Proof-of-concept: Async Rules

Using the new SourceKitten async send support introduced in
https://github.com/jpsim/SourceKitten/pull/762.

.sourcery/GeneratedTests.stencil

@@ -8,8 +8,8 @@ import XCTest
 {% for rule in types.structs %}
 {% if rule.name|hasSuffix:"Rule" %}
 class {{ rule.name }}GeneratedTests: XCTestCase {
-    func testWithDefaultConfiguration() {
-        verifyRule({{ rule.name }}.description)
+    func testWithDefaultConfiguration() async throws {
+        try await verifyRule({{ rule.name }}.description)
     }
 }
 {% if not forloop.last %}

BUILD

@@ -21,6 +21,7 @@ swift_library(
     module_name = "SwiftLintFramework",
     visibility = ["//visibility:public"],
     deps = [
+        "@com_github_johnsundell_collectionconcurrencykit//:CollectionConcurrencyKit",
         "@com_github_jpsim_sourcekitten//:SourceKittenFramework",
         "@com_github_apple_swift_syntax//:optlibs",
         "@sourcekitten_com_github_jpsim_yams//:Yams",

Source/SwiftLintFramework/Extensions/Request+SwiftLint.swift

@@ -11,6 +11,13 @@ extension Request {
         return try send()
     }
 
+    func sendAsyncIfNotDisabled() async throws -> [String: SourceKitRepresentable] {
+        guard !Self.disableSourceKit else {
+            throw Self.Error.connectionInterrupted("SourceKit is disabled by `SWIFTLINT_DISABLE_SOURCEKIT`.")
+        }
+        return try await asyncSend()
+    }
+
     static func cursorInfo(file: String, offset: ByteCount, arguments: [String]) -> Request {
         .customRequest(request: [
             "key.request": UID("source.request.cursorinfo"),

Source/SwiftLintFramework/Extensions/SwiftLintFile+Cache.swift

@@ -10,6 +10,16 @@ import SwiftParserDiagnostics
 import SwiftSyntax
 
 private typealias FileCacheKey = UUID
+private let responseActorCache = ActorCache { file -> [String: SourceKitRepresentable]? in
+    do {
+        return try Request.editorOpen(file: file.file).sendIfNotDisabled()
+    } catch let error as Request.Error {
+        queuedPrintError(error.description)
+        return nil
+    } catch {
+        return nil
+    }
+}
 private let responseCache = Cache { file -> [String: SourceKitRepresentable]? in
     do {
         return try Request.editorOpen(file: file.file).sendIfNotDisabled()
@@ -20,6 +30,9 @@ private let responseCache = Cache { file -> [String: SourceKitRepresentable]? in
         return nil
     }
 }
+private let structureDictionaryActorCache = ActorCache { file in
+    await responseActorCache.get(file).map(Structure.init).map { SourceKittenDictionary($0.dictionary) }
+}
 private let structureDictionaryCache = Cache { file in
     return responseCache.get(file).map(Structure.init).map { SourceKittenDictionary($0.dictionary) }
 }
@@ -58,6 +71,41 @@ public var parserDiagnosticsDisabledForTests = false
 private let assertHandlers = [FileCacheKey: AssertHandler]()
 private let assertHandlerCache = Cache { file in assertHandlers[file.cacheKey] }
 
+private actor ActorCache<T> {
+    private var values = [FileCacheKey: T]()
+    private let factory: (SwiftLintFile) async -> T
+
+    init(_ factory: @escaping (SwiftLintFile) async -> T) {
+        self.factory = factory
+    }
+
+    func get(_ file: SwiftLintFile) async -> T {
+        let key = file.cacheKey
+        if let cachedValue = values[key] {
+            return cachedValue
+        }
+        let value = await factory(file)
+        values[key] = value
+        return value
+    }
+
+    func invalidate(_ file: SwiftLintFile) {
+        values.removeValue(forKey: file.cacheKey)
+    }
+
+    func clear() {
+        values.removeAll(keepingCapacity: false)
+    }
+
+    func set(key: FileCacheKey, value: T) {
+        values[key] = value
+    }
+
+    func unset(key: FileCacheKey) {
+        values.removeValue(forKey: key)
+    }
+}
+
 private class Cache<T> {
     private var values = [FileCacheKey: T]()
     private let factory: (SwiftLintFile) -> T
@@ -146,6 +194,17 @@ extension SwiftLintFile {
         return structureDictionary
     }
 
+    internal func getStructureDictionary() async throws -> SourceKittenDictionary {
+        guard let structureDictionary = await structureDictionaryActorCache.get(self) else {
+            if let handler = assertHandler {
+                handler()
+                return SourceKittenDictionary([:])
+            }
+            queuedFatalError("Never call this for file that sourcekitd fails.")
+        }
+        return structureDictionary
+    }
+
     internal var syntaxClassifications: SyntaxClassifications { syntaxClassificationsCache.get(self) }
 
     internal var syntaxMap: SwiftLintSyntaxMap {

Source/SwiftLintFramework/Models/Linter.swift

@@ -1,3 +1,4 @@
+import CollectionConcurrencyKit
 import Foundation
 import SourceKittenFramework
 
@@ -61,7 +62,7 @@ private extension Rule {
               storage: RuleStorage,
               configuration: Configuration,
               superfluousDisableCommandRule: SuperfluousDisableCommandRule?,
-              compilerArguments: [String]) -> LintResult? {
+              compilerArguments: [String]) async throws -> LintResult? {
         // Empty files shouldn't trigger violations
         guard !file.isEmpty, SwiftVersion.current >= Self.description.minSwiftVersion else {
             return nil
@@ -78,10 +79,10 @@ private extension Rule {
         let ruleTime: (String, Double)?
         if benchmark {
             let start = Date()
-            violations = validate(file: file, using: storage, compilerArguments: compilerArguments)
+            violations = try await validate(file: file, using: storage, compilerArguments: compilerArguments)
             ruleTime = (ruleID, -start.timeIntervalSinceNow)
         } else {
-            violations = validate(file: file, using: storage, compilerArguments: compilerArguments)
+            violations = try await validate(file: file, using: storage, compilerArguments: compilerArguments)
             ruleTime = nil
         }
 
@@ -193,8 +194,8 @@ public struct CollectedLinter {
     /// - parameter storage: The storage object containing all collected info.
     ///
     /// - returns: All style violations found by this linter.
-    public func styleViolations(using storage: RuleStorage) -> [StyleViolation] {
-        return getStyleViolations(using: storage).0
+    public func styleViolations(using storage: RuleStorage) async throws -> [StyleViolation] {
+        return try await getStyleViolations(using: storage).0
     }
 
     /// Computes or retrieves style violations and the time spent executing each rule.
@@ -203,12 +204,13 @@ public struct CollectedLinter {
     ///
     /// - returns: All style violations found by this linter, and the time spent executing each rule.
     public func styleViolationsAndRuleTimes(using storage: RuleStorage)
-        -> ([StyleViolation], [(id: String, time: Double)]) {
-            return getStyleViolations(using: storage, benchmark: true)
+        async throws -> ([StyleViolation], [(id: String, time: Double)]) {
+            return try await getStyleViolations(using: storage, benchmark: true)
     }
 
     private func getStyleViolations(using storage: RuleStorage,
-                                    benchmark: Bool = false) -> ([StyleViolation], [(id: String, time: Double)]) {
+                                    benchmark: Bool = false) async throws
+        -> ([StyleViolation], [(id: String, time: Double)]) {
         guard !file.isEmpty else {
             // Empty files shouldn't trigger violations
             return ([], [])
@@ -222,12 +224,12 @@ public struct CollectedLinter {
         let superfluousDisableCommandRule = rules.first(where: {
             $0 is SuperfluousDisableCommandRule
         }) as? SuperfluousDisableCommandRule
-        let validationResults = rules.parallelCompactMap {
-            $0.lint(file: self.file, regions: regions, benchmark: benchmark,
-                    storage: storage,
-                    configuration: self.configuration,
-                    superfluousDisableCommandRule: superfluousDisableCommandRule,
-                    compilerArguments: self.compilerArguments)
+        let validationResults = try await rules.concurrentCompactMap {
+            try await $0.lint(file: self.file, regions: regions, benchmark: benchmark,
+                              storage: storage,
+                              configuration: self.configuration,
+                              superfluousDisableCommandRule: superfluousDisableCommandRule,
+                              compilerArguments: self.compilerArguments)
         }
         let undefinedSuperfluousCommandViolations = self.undefinedSuperfluousCommandViolations(
             regions: regions, configuration: configuration,

Source/SwiftLintFramework/Protocols/ASTRule.swift

@@ -26,8 +26,8 @@ public protocol ASTRule: Rule {
 }
 
 public extension ASTRule {
-    func validate(file: SwiftLintFile) -> [StyleViolation] {
-        return validate(file: file, dictionary: file.structureDictionary)
+    func validate(file: SwiftLintFile) async throws -> [StyleViolation] {
+        return validate(file: file, dictionary: try await file.getStructureDictionary())
     }
 
     /// Executes the rule on a file and a subset of its AST structure, returning any violations to the rule's

Source/SwiftLintFramework/Protocols/CollectingRule.swift

@@ -60,10 +60,10 @@ public extension CollectingRule {
                   compilerArguments: [String]) -> [StyleViolation] {
         return validate(file: file, collectedInfo: collectedInfo)
     }
-    func validate(file: SwiftLintFile) -> [StyleViolation] {
+    func validate(file: SwiftLintFile) async throws -> [StyleViolation] {
         queuedFatalError("Must call `validate(file:collectedInfo:)` for CollectingRule")
     }
-    func validate(file: SwiftLintFile, compilerArguments: [String]) -> [StyleViolation] {
+    func validate(file: SwiftLintFile, compilerArguments: [String]) async throws -> [StyleViolation] {
         queuedFatalError("Must call `validate(file:collectedInfo:compilerArguments:)` for CollectingRule")
     }
 }
@@ -74,7 +74,7 @@ public extension CollectingRule where Self: AnalyzerRule {
             "Must call `collect(infoFor:compilerArguments:)` for AnalyzerRule & CollectingRule"
         )
     }
-    func validate(file: SwiftLintFile) -> [StyleViolation] {
+    func validate(file: SwiftLintFile) async throws -> [StyleViolation] {
         queuedFatalError(
             "Must call `validate(file:collectedInfo:compilerArguments:)` for AnalyzerRule & CollectingRule"
         )

Source/SwiftLintFramework/Protocols/Rule.swift

@@ -25,14 +25,14 @@ public protocol Rule {
     /// - parameter compilerArguments: The compiler arguments needed to compile this file.
     ///
     /// - returns: All style violations to the rule's expectations.
-    func validate(file: SwiftLintFile, compilerArguments: [String]) -> [StyleViolation]
+    func validate(file: SwiftLintFile, compilerArguments: [String]) async throws -> [StyleViolation]
 
     /// Executes the rule on a file and returns any violations to the rule's expectations.
     ///
     /// - parameter file: The file for which to execute the rule.
     ///
     /// - returns: All style violations to the rule's expectations.
-    func validate(file: SwiftLintFile) -> [StyleViolation]
+    func validate(file: SwiftLintFile) async throws -> [StyleViolation]
 
     /// Whether or not the specified rule is equivalent to the current rule.
     ///
@@ -60,17 +60,18 @@ public protocol Rule {
     /// - parameter compilerArguments: The compiler arguments needed to compile this file.
     ///
     /// - returns: All style violations to the rule's expectations.
-    func validate(file: SwiftLintFile, using storage: RuleStorage, compilerArguments: [String]) -> [StyleViolation]
+    func validate(file: SwiftLintFile, using storage: RuleStorage, compilerArguments: [String]) async throws
+        -> [StyleViolation]
 }
 
 extension Rule {
     public func validate(file: SwiftLintFile, using storage: RuleStorage,
-                         compilerArguments: [String]) -> [StyleViolation] {
-        return validate(file: file, compilerArguments: compilerArguments)
+                         compilerArguments: [String]) async throws -> [StyleViolation] {
+        return try await validate(file: file, compilerArguments: compilerArguments)
     }
 
-    public func validate(file: SwiftLintFile, compilerArguments: [String]) -> [StyleViolation] {
-        return validate(file: file)
+    public func validate(file: SwiftLintFile, compilerArguments: [String]) async throws -> [StyleViolation] {
+        return try await validate(file: file)
     }
 
     public func isEqualTo(_ rule: Rule) -> Bool {
@@ -200,9 +201,10 @@ public protocol SubstitutionCorrectableASTRule: SubstitutionCorrectableRule, AST
 
 public extension SubstitutionCorrectableASTRule {
     func violationRanges(in file: SwiftLintFile) -> [NSRange] {
-        return file.structureDictionary.traverseDepthFirst { subDict in
-            guard let kind = self.kind(from: subDict) else { return nil }
-            return violationRanges(in: file, kind: kind, dictionary: subDict)
+        file.structureDictionary.traverseDepthFirst { subDict in
+            kind(from: subDict).flatMap { kind in
+                violationRanges(in: file, kind: kind, dictionary: subDict)
+            }
         }
     }
 }
@@ -215,7 +217,7 @@ public protocol SourceKitFreeRule: Rule {}
 public protocol AnalyzerRule: OptInRule {}
 
 public extension AnalyzerRule {
-    func validate(file: SwiftLintFile) -> [StyleViolation] {
+    func validate(file: SwiftLintFile) async throws -> [StyleViolation] {
         queuedFatalError("Must call `validate(file:compilerArguments:)` for AnalyzerRule")
     }
 }

Source/SwiftLintFramework/Protocols/SwiftSyntaxRule.swift

@@ -53,7 +53,7 @@ public extension SwiftSyntaxRule {
             .compactMap { $0.toSourceRange(locationConverter: locationConverter) }
     }
 
-    func validate(file: SwiftLintFile) -> [StyleViolation] {
+    func validate(file: SwiftLintFile) async throws -> [StyleViolation] {
         guard let syntaxTree = preprocess(file: file) else {
             return []
         }

Source/SwiftLintFramework/Rules/Idiomatic/DuplicateImportsRule.swift

@@ -132,7 +132,7 @@ struct DuplicateImportsRule: ConfigurationProviderRule, CorrectableRule {
         })
     }
 
-    func validate(file: SwiftLintFile) -> [StyleViolation] {
+    func validate(file: SwiftLintFile) async throws -> [StyleViolation] {
         return duplicateImports(file: file).map { duplicateImport in
             StyleViolation(
                 ruleDescription: Self.description,

Source/SwiftLintFramework/Rules/Idiomatic/ExplicitACLRule.swift

@@ -122,8 +122,10 @@ struct ExplicitACLRule: OptInRule, ConfigurationProviderRule {
         }
     }
 
-    func validate(file: SwiftLintFile) -> [StyleViolation] {
-        let implicitAndExplicitInternalElements = internalTypeElements(in: file.structureDictionary)
+    func validate(file: SwiftLintFile) async throws -> [StyleViolation] {
+        let implicitAndExplicitInternalElements = internalTypeElements(
+            in: try await file.getStructureDictionary()
+        )
 
         guard implicitAndExplicitInternalElements.isNotEmpty else {
             return []

Source/SwiftLintFramework/Rules/Idiomatic/FileNameNoSpaceRule.swift

@@ -16,7 +16,7 @@ struct FileNameNoSpaceRule: ConfigurationProviderRule, OptInRule, SourceKitFreeR
         kind: .idiomatic
     )
 
-    func validate(file: SwiftLintFile) -> [StyleViolation] {
+    func validate(file: SwiftLintFile) async throws -> [StyleViolation] {
         guard let filePath = file.path,
             case let fileName = filePath.bridge().lastPathComponent,
             !configuration.excluded.contains(fileName),

Source/SwiftLintFramework/Rules/Idiomatic/FileNameRule.swift

@@ -18,7 +18,7 @@ struct FileNameRule: ConfigurationProviderRule, OptInRule, SourceKitFreeRule {
         kind: .idiomatic
     )
 
-    func validate(file: SwiftLintFile) -> [StyleViolation] {
+    func validate(file: SwiftLintFile) async throws -> [StyleViolation] {
         guard let filePath = file.path,
             case let fileName = filePath.bridge().lastPathComponent,
             !configuration.excluded.contains(fileName) else {

Source/SwiftLintFramework/Rules/Idiomatic/NimbleOperatorRule.swift

@@ -98,7 +98,7 @@ struct NimbleOperatorRule: ConfigurationProviderRule, OptInRule, CorrectableRule
         "beNil": (to: "==", toNot: "!=", .nullary(analogueValue: "nil"))
     ]
 
-    func validate(file: SwiftLintFile) -> [StyleViolation] {
+    func validate(file: SwiftLintFile) async throws -> [StyleViolation] {
         let matches = violationMatchesRanges(in: file)
         return matches.map {
             StyleViolation(ruleDescription: Self.description,

Source/SwiftLintFramework/Rules/Idiomatic/NoGroupingExtensionRule.swift

@@ -23,8 +23,10 @@ struct NoGroupingExtensionRule: OptInRule, ConfigurationProviderRule {
         ]
     )
 
-    func validate(file: SwiftLintFile) -> [StyleViolation] {
-        let collector = NamespaceCollector(dictionary: file.structureDictionary)
+    func validate(file: SwiftLintFile) async throws -> [StyleViolation] {
+        let collector = NamespaceCollector(
+            dictionary: try await file.getStructureDictionary()
+        )
         let elements = collector.findAllElements(of: [.class, .enum, .struct, .extension])
 
         let susceptibleNames = Set(elements.compactMap { $0.kind != .extension ? $0.name : nil })

Source/SwiftLintFramework/Rules/Idiomatic/RedundantTypeAnnotationRule.swift

@@ -76,7 +76,7 @@ struct RedundantTypeAnnotationRule: OptInRule, SubstitutionCorrectableRule, Conf
         ]
     )
 
-    func validate(file: SwiftLintFile) -> [StyleViolation] {
+    func validate(file: SwiftLintFile) async throws -> [StyleViolation] {
         return violationRanges(in: file).map { range in
             StyleViolation(
                 ruleDescription: Self.description,

Source/SwiftLintFramework/Rules/Idiomatic/SyntacticSugarRule.swift

@@ -17,7 +17,7 @@ struct SyntacticSugarRule: CorrectableRule, ConfigurationProviderRule, SourceKit
         corrections: SyntacticSugarRuleExamples.corrections
     )
 
-    func validate(file: SwiftLintFile) -> [StyleViolation] {
+    func validate(file: SwiftLintFile) async throws -> [StyleViolation] {
         let visitor = SyntacticSugarRuleVisitor(viewMode: .sourceAccurate)
         return visitor.walk(file: file) { visitor in
             flattenViolations(visitor.violations)

Source/SwiftLintFramework/Rules/Lint/CommentSpacingRule.swift

@@ -150,7 +150,7 @@ struct CommentSpacingRule: SourceKitFreeRule, ConfigurationProviderRule, Substit
             .flatMap { $0 }
     }
 
-    func validate(file: SwiftLintFile) -> [StyleViolation] {
+    func validate(file: SwiftLintFile) async throws -> [StyleViolation] {
         return violationRanges(in: file).map { range in
             StyleViolation(
                 ruleDescription: Self.description,

Source/SwiftLintFramework/Rules/Lint/ExpiringTodoRule.swift

@@ -48,7 +48,7 @@ struct ExpiringTodoRule: ConfigurationProviderRule, OptInRule {
 
     init() {}
 
-    func validate(file: SwiftLintFile) -> [StyleViolation] {
+    func validate(file: SwiftLintFile) async throws -> [StyleViolation] {
         let regex = #"""
         \b(?:TODO|FIXME)(?::|\b)(?:(?!\b(?:TODO|FIXME)(?::|\b)).)*?\#
         \\#(configuration.dateDelimiters.opening)\#

Source/SwiftLintFramework/Rules/Lint/MarkRule.swift

@@ -102,7 +102,7 @@ struct MarkRule: CorrectableRule, ConfigurationProviderRule {
         ].joined(separator: "|")
     }
 
-    func validate(file: SwiftLintFile) -> [StyleViolation] {
+    func validate(file: SwiftLintFile) async throws -> [StyleViolation] {
         return violationRanges(in: file, matching: pattern).map {
             StyleViolation(ruleDescription: Self.description,
                            severity: configuration.severity,

Source/SwiftLintFramework/Rules/Lint/MissingDocsRule.swift

@@ -119,9 +119,9 @@ struct MissingDocsRule: OptInRule, ConfigurationProviderRule {
         ]
     )
 
-    func validate(file: SwiftLintFile) -> [StyleViolation] {
+    func validate(file: SwiftLintFile) async throws -> [StyleViolation] {
         let acls = configuration.parameters.map { $0.value }
-        let dict = file.structureDictionary
+        let dict = try await file.getStructureDictionary()
         return file.missingDocOffsets(
             in: dict,
             acls: acls,

Source/SwiftLintFramework/Rules/Lint/OrphanedDocCommentRule.swift

@@ -46,7 +46,7 @@ struct OrphanedDocCommentRule: SourceKitFreeRule, ConfigurationProviderRule {
         ]
     )
 
-    func validate(file: SwiftLintFile) -> [StyleViolation] {
+    func validate(file: SwiftLintFile) async throws -> [StyleViolation] {
         file.syntaxClassifications
             .filter { $0.kind != .none }
             .pairs()

Source/SwiftLintFramework/Rules/Lint/PeriodSpacingRule.swift

@@ -78,7 +78,7 @@ struct PeriodSpacingRule: SourceKitFreeRule, ConfigurationProviderRule, OptInRul
             .flatMap { $0 }
     }
 
-    func validate(file: SwiftLintFile) -> [StyleViolation] {
+    func validate(file: SwiftLintFile) async throws -> [StyleViolation] {
         return violationRanges(in: file).map { range in
             StyleViolation(
                 ruleDescription: Self.description,

Source/SwiftLintFramework/Rules/Lint/QuickDiscouragedCallRule.swift

@@ -14,8 +14,8 @@ struct QuickDiscouragedCallRule: OptInRule, ConfigurationProviderRule {
         triggeringExamples: QuickDiscouragedCallRuleExamples.triggeringExamples
     )
 
-    func validate(file: SwiftLintFile) -> [StyleViolation] {
-        let dict = file.structureDictionary
+    func validate(file: SwiftLintFile) async throws -> [StyleViolation] {
+        let dict = try await file.getStructureDictionary()
         let testClasses = dict.substructure.filter {
             return $0.inheritedTypes.isNotEmpty &&
                 $0.declarationKind == .class

Source/SwiftLintFramework/Rules/Lint/SuperfluousDisableCommandRule.swift

@@ -14,7 +14,7 @@ public struct SuperfluousDisableCommandRule: ConfigurationProviderRule, SourceKi
         kind: .lint
     )
 
-    public func validate(file: SwiftLintFile) -> [StyleViolation] {
+    public func validate(file: SwiftLintFile) async throws -> [StyleViolation] {
         // This rule is implemented in Linter.swift
         return []
     }

Source/SwiftLintFramework/Rules/Lint/TodoRule.swift

@@ -71,7 +71,7 @@ struct TodoRule: ConfigurationProviderRule {
         return reason
     }
 
-    func validate(file: SwiftLintFile) -> [StyleViolation] {
+    func validate(file: SwiftLintFile) async throws -> [StyleViolation] {
         return file.match(pattern: "\\b(?:TODO|FIXME)(?::|\\b)").compactMap { range, syntaxKinds in
             if syntaxKinds.contains(where: { !$0.isCommentLike }) {
                 return nil

Source/SwiftLintFramework/Rules/Lint/TypesafeArrayInitRule.swift

@@ -58,7 +58,7 @@ struct TypesafeArrayInitRule: AnalyzerRule, ConfigurationProviderRule {
             \\Q(Self) -> ((Self.Element) throws -> T) throws -> [T]\\E
             """)
 
-    func validate(file: SwiftLintFile, compilerArguments: [String]) -> [StyleViolation] {
+    func validate(file: SwiftLintFile, compilerArguments: [String]) async throws -> [StyleViolation] {
         guard let filePath = file.path else {
             return []
         }
@@ -69,7 +69,7 @@ struct TypesafeArrayInitRule: AnalyzerRule, ConfigurationProviderRule {
                 """)
             return []
         }
-        return Self.parentRule.validate(file: file)
+        return try await Self.parentRule.validate(file: file)
             .filter { violation in
                 guard let offset = getOffset(in: file, at: violation.location) else {
                     return false

Source/SwiftLintFramework/Rules/Lint/UnusedImportRule.swift

@@ -20,7 +20,7 @@ struct UnusedImportRule: CorrectableRule, ConfigurationProviderRule, AnalyzerRul
         requiresFileOnDisk: true
     )
 
-    func validate(file: SwiftLintFile, compilerArguments: [String]) -> [StyleViolation] {
+    func validate(file: SwiftLintFile, compilerArguments: [String]) async throws -> [StyleViolation] {
         return importUsage(in: file, compilerArguments: compilerArguments).map { importUsage in
             StyleViolation(ruleDescription: Self.description,
                            severity: configuration.severity.severity,

Source/SwiftLintFramework/Rules/Metrics/FileLengthRule.swift

@@ -20,7 +20,7 @@ struct FileLengthRule: ConfigurationProviderRule {
         ].skipWrappingInCommentTests()
     )
 
-    func validate(file: SwiftLintFile) -> [StyleViolation] {
+    func validate(file: SwiftLintFile) async throws -> [StyleViolation] {
         func lineCountWithoutComments() -> Int {
             let commentKinds = SyntaxKind.commentKinds
             let lineCount = file.syntaxKindsByLines.filter { kinds in

Source/SwiftLintFramework/Rules/Metrics/LargeTupleRule.swift

@@ -14,7 +14,7 @@ struct LargeTupleRule: SourceKitFreeRule, ConfigurationProviderRule {
         triggeringExamples: LargeTupleRuleExamples.triggeringExamples
     )
 
-    func validate(file: SwiftLintFile) -> [StyleViolation] {
+    func validate(file: SwiftLintFile) async throws -> [StyleViolation] {
         LargeTupleRuleVisitor(viewMode: .sourceAccurate)
             .walk(file: file, handler: \.violationPositions)
             .sorted(by: { $0.position < $1.position })

Source/SwiftLintFramework/Rules/Metrics/LineLengthRule.swift

@@ -27,7 +27,7 @@ struct LineLengthRule: ConfigurationProviderRule {
         ].skipWrappingInCommentTests().skipWrappingInStringTests()
     )
 
-    func validate(file: SwiftLintFile) -> [StyleViolation] {
+    func validate(file: SwiftLintFile) async throws -> [StyleViolation] {
         let minValue = configuration.params.map({ $0.value }).min() ?? .max
         let swiftDeclarationKindsByLine = Lazy(file.swiftDeclarationKindsByLine() ?? [])
         let syntaxKindsByLine = Lazy(file.syntaxKindsByLine() ?? [])

Source/SwiftLintFramework/Rules/Metrics/NestingRule.swift

@@ -35,8 +35,9 @@ struct NestingRule: ConfigurationProviderRule {
         }
     }
 
-    func validate(file: SwiftLintFile) -> [StyleViolation] {
-        return validate(file: file, substructure: file.structureDictionary.substructure, args: ValidationArgs())
+    func validate(file: SwiftLintFile) async throws -> [StyleViolation] {
+        let substructure = try await file.getStructureDictionary().substructure
+        return validate(file: file, substructure: substructure, args: ValidationArgs())
     }
 
     private func validate(file: SwiftLintFile, substructure: [SourceKittenDictionary],

Source/SwiftLintFramework/Rules/Style/ClosureEndIndentationRule.swift

@@ -18,7 +18,7 @@ struct ClosureEndIndentationRule: Rule, OptInRule, ConfigurationProviderRule {
 
     fileprivate static let notWhitespace = regex("[^\\s]")
 
-    func validate(file: SwiftLintFile) -> [StyleViolation] {
+    func validate(file: SwiftLintFile) async throws -> [StyleViolation] {
         return violations(in: file).map { violation in
             return styleViolation(for: violation, in: file)
         }

Source/SwiftLintFramework/Rules/Style/ColonRule.swift

@@ -19,7 +19,7 @@ struct ColonRule: SubstitutionCorrectableRule, ConfigurationProviderRule, Source
         corrections: ColonRuleExamples.corrections
     )
 
-    func validate(file: SwiftLintFile) -> [StyleViolation] {
+    func validate(file: SwiftLintFile) async throws -> [StyleViolation] {
         violationRanges(in: file).map { range in
             StyleViolation(ruleDescription: Self.description,
                            severity: configuration.severityConfiguration.severity,

Source/SwiftLintFramework/Rules/Style/CommaInheritanceRule.swift

@@ -62,7 +62,7 @@ struct CommaInheritanceRule: OptInRule, SubstitutionCorrectableRule, Configurati
 
     // MARK: - Rule
 
-    func validate(file: SwiftLintFile) -> [StyleViolation] {
+    func validate(file: SwiftLintFile) async throws -> [StyleViolation] {
         return violationRanges(in: file).map {
             StyleViolation(ruleDescription: Self.description,
                            severity: configuration.severity,

Source/SwiftLintFramework/Rules/Style/CommaRule.swift

@@ -90,7 +90,7 @@ struct CommaRule: CorrectableRule, ConfigurationProviderRule, SourceKitFreeRule
         ]
     )
 
-    func validate(file: SwiftLintFile) -> [StyleViolation] {
+    func validate(file: SwiftLintFile) async throws -> [StyleViolation] {
         return violationRanges(in: file).map {
             StyleViolation(ruleDescription: Self.description,
                            severity: configuration.severity,

Source/SwiftLintFramework/Rules/Style/ControlStatementRule.swift

@@ -80,7 +80,7 @@ struct ControlStatementRule: ConfigurationProviderRule, SubstitutionCorrectableR
         ]
     )
 
-    func validate(file: SwiftLintFile) -> [StyleViolation] {
+    func validate(file: SwiftLintFile) async throws -> [StyleViolation] {
         return violationRanges(in: file).map { match -> StyleViolation in
             return StyleViolation(ruleDescription: Self.description,
                                   severity: configuration.severity,

Source/SwiftLintFramework/Rules/Style/CustomRules.swift

@@ -80,7 +80,7 @@ struct CustomRules: Rule, ConfigurationProviderRule, CacheDescriptionProvider {
 
     var configuration = CustomRulesConfiguration()
 
-    func validate(file: SwiftLintFile) -> [StyleViolation] {
+    func validate(file: SwiftLintFile) async throws -> [StyleViolation] {
         var configurations = configuration.customRuleConfigurations
 
         guard configurations.isNotEmpty else {

Source/SwiftLintFramework/Rules/Style/ExplicitSelfRule.swift

@@ -17,7 +17,7 @@ struct ExplicitSelfRule: CorrectableRule, ConfigurationProviderRule, AnalyzerRul
         requiresFileOnDisk: true
     )
 
-    func validate(file: SwiftLintFile, compilerArguments: [String]) -> [StyleViolation] {
+    func validate(file: SwiftLintFile, compilerArguments: [String]) async throws -> [StyleViolation] {
         return violationRanges(in: file, compilerArguments: compilerArguments).map {
             StyleViolation(ruleDescription: Self.description,
                            severity: configuration.severity,

Source/SwiftLintFramework/Rules/Style/FileHeaderRule.swift

@@ -33,7 +33,7 @@ struct FileHeaderRule: ConfigurationProviderRule, OptInRule {
         ].skipWrappingInCommentTests()
     )
 
-    func validate(file: SwiftLintFile) -> [StyleViolation] {
+    func validate(file: SwiftLintFile) async throws -> [StyleViolation] {
         var firstToken: SwiftLintSyntaxToken?
         var lastToken: SwiftLintSyntaxToken?
         var firstNonCommentToken: SwiftLintSyntaxToken?

Source/SwiftLintFramework/Rules/Style/FileTypesOrderRule.swift

@@ -17,26 +17,26 @@ struct FileTypesOrderRule: ConfigurationProviderRule, OptInRule {
         triggeringExamples: FileTypesOrderRuleExamples.triggeringExamples
     )
 
-    func validate(file: SwiftLintFile) -> [StyleViolation] {
-        guard let mainTypeSubstructure = mainTypeSubstructure(in: file),
+    func validate(file: SwiftLintFile) async throws -> [StyleViolation] {
+        guard let mainTypeSubstructure = try await mainTypeSubstructure(in: file),
               let mainTypeSubstuctureOffset = mainTypeSubstructure.offset else { return [] }
 
-        let extensionsSubstructures = self.extensionsSubstructures(
+        let extensionsSubstructures = try await self.extensionsSubstructures(
             in: file,
             mainTypeSubstructure: mainTypeSubstructure
         )
 
-        let supportingTypesSubstructures = self.supportingTypesSubstructures(
+        let supportingTypesSubstructures = try await self.supportingTypesSubstructures(
             in: file,
             mainTypeSubstructure: mainTypeSubstructure
         )
 
-        let previewProviderSubstructures = self.substructures(
+        let previewProviderSubstructures = try await self.substructures(
             in: file,
             withInheritedType: "PreviewProvider"
         )
 
-        let libraryContentSubstructures = self.substructures(
+        let libraryContentSubstructures = try await self.substructures(
             in: file,
             withInheritedType: "LibraryContentProvider"
         )
@@ -95,8 +95,8 @@ struct FileTypesOrderRule: ConfigurationProviderRule, OptInRule {
     private func extensionsSubstructures(
         in file: SwiftLintFile,
         mainTypeSubstructure: SourceKittenDictionary
-    ) -> [SourceKittenDictionary] {
-        let dict = file.structureDictionary
+    ) async throws -> [SourceKittenDictionary] {
+        let dict = try await file.getStructureDictionary()
         return dict.substructure.filter { substructure in
             guard let kind = substructure.kind else { return false }
             return substructure.offset != mainTypeSubstructure.offset
@@ -107,11 +107,11 @@ struct FileTypesOrderRule: ConfigurationProviderRule, OptInRule {
     private func supportingTypesSubstructures(
         in file: SwiftLintFile,
         mainTypeSubstructure: SourceKittenDictionary
-    ) -> [SourceKittenDictionary] {
+    ) async throws -> [SourceKittenDictionary] {
         var supportingTypeKinds = SwiftDeclarationKind.typeKinds
         supportingTypeKinds.insert(SwiftDeclarationKind.protocol)
 
-        let dict = file.structureDictionary
+        let dict = try await file.getStructureDictionary()
         return dict.substructure.filter { substructure in
             guard let declarationKind = substructure.declarationKind else { return false }
             guard !substructure.hasExcludedInheritedType else { return false }
@@ -124,14 +124,14 @@ struct FileTypesOrderRule: ConfigurationProviderRule, OptInRule {
     private func substructures(
         in file: SwiftLintFile,
         withInheritedType inheritedType: String
-    ) -> [SourceKittenDictionary] {
-        file.structureDictionary.substructure.filter { substructure in
+    ) async throws -> [SourceKittenDictionary] {
+        try await file.getStructureDictionary().substructure.filter { substructure in
             substructure.inheritedTypes.contains(inheritedType)
         }
     }
 
-    private func mainTypeSubstructure(in file: SwiftLintFile) -> SourceKittenDictionary? {
-        let dict = file.structureDictionary
+    private func mainTypeSubstructure(in file: SwiftLintFile) async throws -> SourceKittenDictionary? {
+        let dict = try await file.getStructureDictionary()
 
         guard let filePath = file.path else {
             return self.mainTypeSubstructure(in: dict)
@@ -140,7 +140,7 @@ struct FileTypesOrderRule: ConfigurationProviderRule, OptInRule {
         let fileName = URL(fileURLWithPath: filePath, isDirectory: false)
             .lastPathComponent.replacingOccurrences(of: ".swift", with: "")
         guard let mainTypeSubstructure = dict.substructure.first(where: { $0.name == fileName }) else {
-            return self.mainTypeSubstructure(in: file.structureDictionary)
+            return self.mainTypeSubstructure(in: try await file.getStructureDictionary())
         }
 
         // specify type with name matching the files name as main type

Source/SwiftLintFramework/Rules/Style/ImplicitReturnRule.swift

@@ -16,7 +16,7 @@ struct ImplicitReturnRule: ConfigurationProviderRule, SubstitutionCorrectableRul
         corrections: ImplicitReturnRuleExamples.corrections
     )
 
-    func validate(file: SwiftLintFile) -> [StyleViolation] {
+    func validate(file: SwiftLintFile) async throws -> [StyleViolation] {
         return violationRanges(in: file).compactMap {
             StyleViolation(ruleDescription: Self.description,
                            severity: configuration.severityConfiguration.severity,

Source/SwiftLintFramework/Rules/Style/IndentationWidthRule.swift

@@ -47,7 +47,7 @@ struct IndentationWidthRule: ConfigurationProviderRule, OptInRule {
     init() {}
 
     // MARK: - Methods: Validation
-    func validate(file: SwiftLintFile) -> [StyleViolation] { // swiftlint:disable:this function_body_length
+    func validate(file: SwiftLintFile) async throws -> [StyleViolation] { // swiftlint:disable:this function_body_length
         var violations: [StyleViolation] = []
         var previousLineIndentations: [Indentation] = []
 

Source/SwiftLintFramework/Rules/Style/LeadingWhitespaceRule.swift

@@ -23,7 +23,7 @@ struct LeadingWhitespaceRule: CorrectableRule, ConfigurationProviderRule, Source
         ]
     )
 
-    func validate(file: SwiftLintFile) -> [StyleViolation] {
+    func validate(file: SwiftLintFile) async throws -> [StyleViolation] {
         let countOfLeadingWhitespace = file.contents.countOfLeadingCharacters(in: .whitespacesAndNewlines)
         if countOfLeadingWhitespace == 0 {
             return []

Source/SwiftLintFramework/Rules/Style/LetVarWhitespaceRule.swift

@@ -62,8 +62,8 @@ struct LetVarWhitespaceRule: ConfigurationProviderRule, OptInRule {
         ]
     )
 
-    func validate(file: SwiftLintFile) -> [StyleViolation] {
-        let dict = file.structureDictionary
+    func validate(file: SwiftLintFile) async throws -> [StyleViolation] {
+        let dict = try await file.getStructureDictionary()
 
         var attributeLines = attributeLineNumbers(file: file)
         var varLines = Set<Int>()

Source/SwiftLintFramework/Rules/Style/LiteralExpressionEndIdentationRule.swift

@@ -123,7 +123,7 @@ struct LiteralExpressionEndIdentationRule: Rule, ConfigurationProviderRule, OptI
         ]
     )
 
-    func validate(file: SwiftLintFile) -> [StyleViolation] {
+    func validate(file: SwiftLintFile) async throws -> [StyleViolation] {
         return violations(in: file).map { violation in
             return styleViolation(for: violation, in: file)
         }

Source/SwiftLintFramework/Rules/Style/MultilineParametersBracketsRule.swift

@@ -92,8 +92,8 @@ struct MultilineParametersBracketsRule: OptInRule, ConfigurationProviderRule {
         ]
     )
 
-    func validate(file: SwiftLintFile) -> [StyleViolation] {
-        return violations(in: file.structureDictionary, file: file)
+    func validate(file: SwiftLintFile) async throws -> [StyleViolation] {
+        return violations(in: try await file.getStructureDictionary(), file: file)
     }
 
     private func violations(in substructure: SourceKittenDictionary, file: SwiftLintFile) -> [StyleViolation] {

Source/SwiftLintFramework/Rules/Style/OpeningBraceRule.swift

@@ -175,7 +175,7 @@ struct OpeningBraceRule: CorrectableRule, ConfigurationProviderRule {
         ]
     )
 
-    func validate(file: SwiftLintFile) -> [StyleViolation] {
+    func validate(file: SwiftLintFile) async throws -> [StyleViolation] {
         return file.violatingOpeningBraceRanges(allowMultilineFunc: configuration.allowMultilineFunc).map {
             StyleViolation(ruleDescription: Self.description,
                            severity: configuration.severityConfiguration.severity,

Source/SwiftLintFramework/Rules/Style/OperatorUsageWhitespaceRule.swift

@@ -17,7 +17,7 @@ struct OperatorUsageWhitespaceRule: OptInRule, CorrectableRule, ConfigurationPro
         corrections: OperatorUsageWhitespaceRuleExamples.corrections
     )
 
-    func validate(file: SwiftLintFile) -> [StyleViolation] {
+    func validate(file: SwiftLintFile) async throws -> [StyleViolation] {
         return violationRanges(file: file).map { range, _ in
             StyleViolation(ruleDescription: Self.description,
                            severity: configuration.severityConfiguration.severity,

Source/SwiftLintFramework/Rules/Style/SingleTestClassRule.swift

@@ -51,7 +51,7 @@ struct SingleTestClassRule: SourceKitFreeRule, OptInRule, ConfigurationProviderR
 
     init() {}
 
-    func validate(file: SwiftLintFile) -> [StyleViolation] {
+    func validate(file: SwiftLintFile) async throws -> [StyleViolation] {
         let classes = TestClassVisitor(viewMode: .sourceAccurate, testClasses: configuration.testParentClasses)
             .walk(tree: file.syntaxTree, handler: \.violations)
 

Source/SwiftLintFramework/Rules/Style/SortedImportsRule.swift

@@ -133,7 +133,7 @@ struct SortedImportsRule: CorrectableRule, ConfigurationProviderRule, OptInRule
         ]
     )
 
-    func validate(file: SwiftLintFile) -> [StyleViolation] {
+    func validate(file: SwiftLintFile) async throws -> [StyleViolation] {
         let groups = importGroups(in: file, filterEnabled: false)
         return violatingOffsets(inGroups: groups).map { index -> StyleViolation in
             let location = Location(file: file, characterOffset: index)

Source/SwiftLintFramework/Rules/Style/StatementPositionRule.swift

@@ -63,7 +63,7 @@ struct StatementPositionRule: CorrectableRule, ConfigurationProviderRule {
         ]
     )
 
-    func validate(file: SwiftLintFile) -> [StyleViolation] {
+    func validate(file: SwiftLintFile) async throws -> [StyleViolation] {
         switch configuration.statementMode {
         case .default:
             return defaultValidate(file: file)

Source/SwiftLintFramework/Rules/Style/TrailingClosureRule.swift

@@ -30,8 +30,8 @@ struct TrailingClosureRule: OptInRule, ConfigurationProviderRule {
         ]
     )
 
-    func validate(file: SwiftLintFile) -> [StyleViolation] {
-        let dict = file.structureDictionary
+    func validate(file: SwiftLintFile) async throws -> [StyleViolation] {
+        let dict = try await file.getStructureDictionary()
         return violationOffsets(for: dict, file: file).map {
             StyleViolation(ruleDescription: Self.description,
                            severity: configuration.severityConfiguration.severity,

Source/SwiftLintFramework/Rules/Style/TrailingNewlineRule.swift

@@ -42,7 +42,7 @@ struct TrailingNewlineRule: CorrectableRule, ConfigurationProviderRule, SourceKi
         ]
     )
 
-    func validate(file: SwiftLintFile) -> [StyleViolation] {
+    func validate(file: SwiftLintFile) async throws -> [StyleViolation] {
         if file.contents.trailingNewlineCount() == 1 {
             return []
         }

Source/SwiftLintFramework/Rules/Style/TrailingWhitespaceRule.swift

@@ -25,7 +25,7 @@ struct TrailingWhitespaceRule: CorrectableRule, ConfigurationProviderRule {
         ]
     )
 
-    func validate(file: SwiftLintFile) -> [StyleViolation] {
+    func validate(file: SwiftLintFile) async throws -> [StyleViolation] {
         let filteredLines = file.lines.filter {
             guard $0.content.hasTrailingWhitespace() else { return false }
 

Source/SwiftLintFramework/Rules/Style/TypeContentsOrderRule.swift

@@ -16,8 +16,8 @@ struct TypeContentsOrderRule: ConfigurationProviderRule, OptInRule {
         triggeringExamples: TypeContentsOrderRuleExamples.triggeringExamples
     )
 
-    func validate(file: SwiftLintFile) -> [StyleViolation] {
-        let dict = file.structureDictionary
+    func validate(file: SwiftLintFile) async throws -> [StyleViolation] {
+        let dict = try await file.getStructureDictionary()
         let substructures = dict.substructure
         return substructures.reduce(into: [StyleViolation]()) { violations, substructure in
             violations.append(contentsOf: validateTypeSubstructure(substructure, in: file))

Source/SwiftLintFramework/Rules/Style/VerticalWhitespaceBetweenCasesRule.swift

@@ -148,7 +148,7 @@ extension VerticalWhitespaceBetweenCasesRule: OptInRule {
         corrections: violatingToValidExamples.removingViolationMarkers()
     )
 
-    func validate(file: SwiftLintFile) -> [StyleViolation] {
+    func validate(file: SwiftLintFile) async throws -> [StyleViolation] {
         let patternRegex = regex(pattern)
         return violationRanges(in: file).compactMap { violationRange in
             let substring = file.contents.substring(from: violationRange.location, length: violationRange.length)

Source/SwiftLintFramework/Rules/Style/VerticalWhitespaceClosingBracesRule.swift

@@ -69,7 +69,7 @@ extension VerticalWhitespaceClosingBracesRule: OptInRule {
         corrections: examples.violatingToValidExamples.removingViolationMarkers()
     )
 
-    func validate(file: SwiftLintFile) -> [StyleViolation] {
+    func validate(file: SwiftLintFile) async throws -> [StyleViolation] {
         let pattern = configuration.onlyEnforceBeforeTrivialLines ? self.trivialLinePattern : self.pattern
 
         let patternRegex: NSRegularExpression = regex(pattern)

Source/SwiftLintFramework/Rules/Style/VerticalWhitespaceOpeningBracesRule.swift

@@ -155,7 +155,7 @@ extension VerticalWhitespaceOpeningBracesRule: OptInRule {
         corrections: violatingToValidExamples.removingViolationMarkers()
     )
 
-    func validate(file: SwiftLintFile) -> [StyleViolation] {
+    func validate(file: SwiftLintFile) async throws -> [StyleViolation] {
         let patternRegex: NSRegularExpression = regex(pattern)
 
         return file.violatingRanges(for: pattern).map { violationRange in

Source/SwiftLintFramework/Rules/Style/VerticalWhitespaceRule.swift

@@ -38,7 +38,7 @@ struct VerticalWhitespaceRule: CorrectableRule, ConfigurationProviderRule {
         return defaultDescriptionReason
     }
 
-    func validate(file: SwiftLintFile) -> [StyleViolation] {
+    func validate(file: SwiftLintFile) async throws -> [StyleViolation] {
         let linesSections = violatingLineSections(in: file)
         guard linesSections.isNotEmpty else {
             return []

Source/SwiftLintFramework/Rules/Style/VoidReturnRule.swift

@@ -49,7 +49,7 @@ struct VoidReturnRule: ConfigurationProviderRule, SubstitutionCorrectableRule {
         ]
     )
 
-    func validate(file: SwiftLintFile) -> [StyleViolation] {
+    func validate(file: SwiftLintFile) async throws -> [StyleViolation] {
         return violationRanges(in: file).map {
             StyleViolation(ruleDescription: Self.description,
                            severity: configuration.severity,

Source/swiftlint/Extensions/Configuration+CommandLine.swift

@@ -66,9 +66,9 @@ extension Configuration {
                               duplicateFileNames: duplicateFileNames)
             }
         }
-        let result = await Signposts.record(name: "Configuration.VisitLintableFiles.Visit") {
-            await collected.asyncMap { linters, duplicateFileNames in
-                await visit(linters: linters, visitor: visitor, duplicateFileNames: duplicateFileNames)
+        let result = try await Signposts.record(name: "Configuration.VisitLintableFiles.Visit") {
+            try await collected.asyncMap { linters, duplicateFileNames in
+                try await visit(linters: linters, visitor: visitor, duplicateFileNames: duplicateFileNames)
             }
         }
         return result.flatMap { $0 }
@@ -181,7 +181,7 @@ extension Configuration {
 
     private func visit(linters: [CollectedLinter],
                        visitor: LintableFilesVisitor,
-                       duplicateFileNames: Set<String>) async -> [SwiftLintFile] {
+                       duplicateFileNames: Set<String>) async throws -> [SwiftLintFile] {
         let counter = CounterActor()
         let progress = ProgressBar(count: linters.count)
         if visitor.showProgressBar {
@@ -198,12 +198,12 @@ extension Configuration {
                 }
             }
 
-            await Signposts.record(name: "Configuration.Visit", span: .file(linter.file.path ?? "")) {
-                await visitor.block(linter)
+            try await Signposts.record(name: "Configuration.Visit", span: .file(linter.file.path ?? "")) {
+                try await visitor.block(linter)
             }
             return linter.file
         }
-        return await visitor.parallel ?
+        return try await visitor.parallel ?
             linters.concurrentMap(visit) :
             linters.asyncMap(visit)
     }
@@ -244,7 +244,8 @@ extension Configuration {
     }
 
     func visitLintableFiles(options: LintOrAnalyzeOptions, cache: LinterCache? = nil, storage: RuleStorage,
-                            visitorBlock: @escaping (CollectedLinter) async -> Void) async throws -> [SwiftLintFile] {
+                            visitorBlock: @escaping (CollectedLinter) async throws -> Void) async throws
+        -> [SwiftLintFile] {
         let visitor = try LintableFilesVisitor.create(options, cache: cache,
                                                       allowZeroLintableFiles: allowZeroLintableFiles,
                                                       block: visitorBlock)

Source/swiftlint/Helpers/LintOrAnalyzeCommand.swift

@@ -58,7 +58,7 @@ struct LintOrAnalyzeCommand {
             if options.benchmark {
                 CustomRuleTimer.shared.activate()
                 let start = Date()
-                let (violationsBeforeLeniency, currentRuleTimes) = linter
+                let (violationsBeforeLeniency, currentRuleTimes) = try await linter
                     .styleViolationsAndRuleTimes(using: builder.storage)
                 currentViolations = applyLeniency(options: options, violations: violationsBeforeLeniency)
                 visitorMutationQueue.sync {
@@ -68,7 +68,7 @@ struct LintOrAnalyzeCommand {
                 }
             } else {
                 currentViolations = applyLeniency(options: options,
-                                                  violations: linter.styleViolations(using: builder.storage))
+                                                  violations: try await linter.styleViolations(using: builder.storage))
                 visitorMutationQueue.sync {
                     builder.violations += currentViolations
                 }

Source/swiftlint/Helpers/LintableFilesVisitor.swift

@@ -81,12 +81,12 @@ struct LintableFilesVisitor {
     let parallel: Bool
     let allowZeroLintableFiles: Bool
     let mode: LintOrAnalyzeModeWithCompilerArguments
-    let block: (CollectedLinter) async -> Void
+    let block: (CollectedLinter) async throws -> Void
 
     private init(paths: [String], action: String, useSTDIN: Bool, quiet: Bool, showProgressBar: Bool,
                  useScriptInputFiles: Bool, forceExclude: Bool, useExcludingByPrefix: Bool,
                  cache: LinterCache?, compilerInvocations: CompilerInvocations?,
-                 allowZeroLintableFiles: Bool, block: @escaping (CollectedLinter) async -> Void) {
+                 allowZeroLintableFiles: Bool, block: @escaping (CollectedLinter) async throws -> Void) {
         self.paths = resolveParamsFiles(args: paths)
         self.action = action
         self.useSTDIN = useSTDIN
@@ -113,7 +113,7 @@ struct LintableFilesVisitor {
     static func create(_ options: LintOrAnalyzeOptions,
                        cache: LinterCache?,
                        allowZeroLintableFiles: Bool,
-                       block: @escaping (CollectedLinter) async -> Void)
+                       block: @escaping (CollectedLinter) async throws -> Void)
         throws -> LintableFilesVisitor {
         try Signposts.record(name: "LintableFilesVisitor.Create") {
             let compilerInvocations: CompilerInvocations?

Tests/CLITests/RulesFilterTests.swift

@@ -139,7 +139,7 @@ private struct RuleMock1: Rule {
     init() {}
     init(configuration: Any) throws { self.init() }
 
-    func validate(file: SwiftLintFile) -> [StyleViolation] {
+    func validate(file: SwiftLintFile) async throws -> [StyleViolation] {
         return []
     }
 }
@@ -152,7 +152,7 @@ private struct RuleMock2: Rule {
     init() {}
     init(configuration: Any) throws { self.init() }
 
-    func validate(file: SwiftLintFile) -> [StyleViolation] {
+    func validate(file: SwiftLintFile) async throws -> [StyleViolation] {
         return []
     }
 }
@@ -165,7 +165,7 @@ private struct CorrectableRuleMock: CorrectableRule {
     init() {}
     init(configuration: Any) throws { self.init() }
 
-    func validate(file: SwiftLintFile) -> [StyleViolation] {
+    func validate(file: SwiftLintFile) async throws -> [StyleViolation] {
         return []
     }
 

Tests/ExtraRulesTests/ExtraRulesTests.swift

@@ -3,15 +3,15 @@ import SwiftLintTestHelpers
 import XCTest
 
 final class ExtraRulesTests: XCTestCase {
-    func testWithDefaultConfiguration() {
+    func testWithDefaultConfiguration() async throws {
         for ruleType in extraRules() {
-            verifyRule(ruleType.description)
+            try await verifyRule(ruleType.description)
         }
     }
 }
 
 extension ExtraRulesTests {
-    static var allTests: [(String, (ExtraRulesTests) -> () throws -> Void)] {
+    static var allTests: [(String, (ExtraRulesTests) -> () async throws -> Void)] {
         [("testWithDefaultConfiguration", testWithDefaultConfiguration)]
     }
 }

Tests/IntegrationTests/IntegrationTests.swift

@@ -1,3 +1,4 @@
+import CollectionConcurrencyKit
 import Foundation
 import SourceKittenFramework
 @_spi(TestHelper)
@@ -15,7 +16,7 @@ private let config: Configuration = {
 }()
 
 class IntegrationTests: XCTestCase {
-    func testSwiftLintLints() {
+    func testSwiftLintLints() async throws {
         // This is as close as we're ever going to get to a self-hosting linter.
         let swiftFiles = config.lintableFiles(inPath: "", forceExclude: false)
         XCTAssert(
@@ -24,8 +25,8 @@ class IntegrationTests: XCTestCase {
         )
 
         let storage = RuleStorage()
-        let violations = swiftFiles.parallelFlatMap {
-            Linter(file: $0, configuration: config).collect(into: storage).styleViolations(using: storage)
+        let violations = try await swiftFiles.concurrentFlatMap {
+            try await Linter(file: $0, configuration: config).collect(into: storage).styleViolations(using: storage)
         }
         violations.forEach { violation in
             violation.location.file!.withStaticString {

Tests/SwiftLintFrameworkTests/AttributesRuleTests.swift

@@ -2,7 +2,7 @@
 import XCTest
 
 class AttributesRuleTests: XCTestCase {
-    func testAttributesWithAlwaysOnSameLine() {
+    func testAttributesWithAlwaysOnSameLine() async throws {
         // Test with custom `always_on_same_line`
         let nonTriggeringExamples = [
             Example("@objc var x: String"),
@@ -28,11 +28,11 @@ class AttributesRuleTests: XCTestCase {
             .with(triggeringExamples: triggeringExamples)
             .with(nonTriggeringExamples: nonTriggeringExamples)
 
-        verifyRule(alwaysOnSameLineDescription,
-                   ruleConfiguration: ["always_on_same_line": ["@objc"]])
+        try await verifyRule(alwaysOnSameLineDescription,
+                             ruleConfiguration: ["always_on_same_line": ["@objc"]])
     }
 
-    func testAttributesWithAlwaysOnLineAbove() {
+    func testAttributesWithAlwaysOnLineAbove() async throws {
         // Test with custom `always_on_line_above`
         let nonTriggeringExamples = [
             Example("@objc\n var x: String"),
@@ -49,11 +49,11 @@ class AttributesRuleTests: XCTestCase {
             .with(triggeringExamples: triggeringExamples)
             .with(nonTriggeringExamples: nonTriggeringExamples)
 
-        verifyRule(alwaysOnNewLineDescription,
-                   ruleConfiguration: ["always_on_line_above": ["@objc"]])
+        try await verifyRule(alwaysOnNewLineDescription,
+                             ruleConfiguration: ["always_on_line_above": ["@objc"]])
     }
 
-    func testAttributesWithAttributesOnLineAboveButOnOtherDeclaration() {
+    func testAttributesWithAttributesOnLineAboveButOnOtherDeclaration() async throws {
         let nonTriggeringExamples = [
             Example("""
             @IBDesignable open class TagListView: UIView {
@@ -92,8 +92,11 @@ class AttributesRuleTests: XCTestCase {
             .with(triggeringExamples: triggeringExamples)
             .with(nonTriggeringExamples: nonTriggeringExamples)
 
-        verifyRule(alwaysOnNewLineDescription,
-                   ruleConfiguration: ["always_on_same_line": ["@discardableResult", "@objc",
-                                                               "@IBAction", "@IBDesignable"]])
+        try await verifyRule(
+            alwaysOnNewLineDescription,
+            ruleConfiguration: [
+                "always_on_same_line": ["@discardableResult", "@objc", "@IBAction", "@IBDesignable"]
+            ]
+        )
     }
 }

Tests/SwiftLintFrameworkTests/CollectingRuleTests.swift

@@ -5,7 +5,7 @@ import SwiftLintTestHelpers
 import XCTest
 
 class CollectingRuleTests: XCTestCase {
-    func testCollectsIntoStorage() {
+    func testCollectsIntoStorage() async throws {
         struct Spec: MockCollectingRule {
             func collectInfo(for file: SwiftLintFile) -> Int {
                 return 42
@@ -17,10 +17,11 @@ class CollectingRuleTests: XCTestCase {
             }
         }
 
-        XCTAssertFalse(violations(Example("_ = 0"), config: Spec.configuration!).isEmpty)
+        let violations = try await violations(Example("_ = 0"), config: Spec.configuration!)
+        XCTAssertNotEqual(violations, [])
     }
 
-    func testCollectsAllFiles() {
+    func testCollectsAllFiles() async throws {
         struct Spec: MockCollectingRule {
             func collectInfo(for file: SwiftLintFile) -> String {
                 return file.contents
@@ -36,10 +37,11 @@ class CollectingRuleTests: XCTestCase {
         }
 
         let inputs = ["foo", "bar", "baz"]
-        XCTAssertEqual(inputs.violations(config: Spec.configuration!).count, inputs.count)
+        let violations = try await inputs.violations(config: Spec.configuration!)
+        XCTAssertEqual(violations.count, inputs.count)
     }
 
-    func testCollectsAnalyzerFiles() {
+    func testCollectsAnalyzerFiles() async throws {
         struct Spec: MockCollectingRule, AnalyzerRule {
             func collectInfo(for file: SwiftLintFile, compilerArguments: [String]) -> [String] {
                 return compilerArguments
@@ -52,7 +54,8 @@ class CollectingRuleTests: XCTestCase {
             }
         }
 
-        XCTAssertFalse(violations(Example("_ = 0"), config: Spec.configuration!, requiresFileOnDisk: true).isEmpty)
+        let violations = try await violations(Example("_ = 0"), config: Spec.configuration!, requiresFileOnDisk: true)
+        XCTAssertNotEqual(violations, [])
     }
 
     func testCorrects() {

Tests/SwiftLintFrameworkTests/CollectionAlignmentRuleTests.swift

@@ -2,23 +2,23 @@
 import XCTest
 
 class CollectionAlignmentRuleTests: XCTestCase {
-    func testCollectionAlignmentWithAlignLeft() {
+    func testCollectionAlignmentWithAlignLeft() async throws {
         let baseDescription = CollectionAlignmentRule.description
         let examples = CollectionAlignmentRule.Examples(alignColons: false)
 
         let description = baseDescription.with(nonTriggeringExamples: examples.nonTriggeringExamples,
                                                triggeringExamples: examples.triggeringExamples)
 
-        verifyRule(description)
+        try await verifyRule(description)
     }
 
-    func testCollectionAlignmentWithAlignColons() {
+    func testCollectionAlignmentWithAlignColons() async throws {
         let baseDescription = CollectionAlignmentRule.description
         let examples = CollectionAlignmentRule.Examples(alignColons: true)
 
         let description = baseDescription.with(nonTriggeringExamples: examples.nonTriggeringExamples,
                                                triggeringExamples: examples.triggeringExamples)
 
-        verifyRule(description, ruleConfiguration: ["align_colons": true])
+        try await verifyRule(description, ruleConfiguration: ["align_colons": true])
     }
 }

Tests/SwiftLintFrameworkTests/ColonRuleTests.swift

@@ -2,7 +2,7 @@
 import XCTest
 
 class ColonRuleTests: XCTestCase {
-    func testColonWithFlexibleRightSpace() {
+    func testColonWithFlexibleRightSpace() async throws {
         // Verify Colon rule with test values for when flexible_right_spacing
         // is true.
         let nonTriggeringExamples = ColonRule.description.nonTriggeringExamples + [
@@ -65,10 +65,10 @@ class ColonRuleTests: XCTestCase {
                                                .with(nonTriggeringExamples: nonTriggeringExamples)
                                                .with(corrections: corrections)
 
-        verifyRule(description, ruleConfiguration: ["flexible_right_spacing": true])
+        try await verifyRule(description, ruleConfiguration: ["flexible_right_spacing": true])
     }
 
-    func testColonWithoutApplyToDictionaries() {
+    func testColonWithoutApplyToDictionaries() async throws {
         let nonTriggeringExamples = ColonRule.description.nonTriggeringExamples + [
             Example("let abc = [Void:Void]()\n"),
             Example("let abc = [Void : Void]()\n"),
@@ -130,6 +130,6 @@ class ColonRuleTests: XCTestCase {
                                                .with(nonTriggeringExamples: nonTriggeringExamples)
                                                .with(corrections: corrections)
 
-        verifyRule(description, ruleConfiguration: ["apply_to_dictionaries": false])
+        try await verifyRule(description, ruleConfiguration: ["apply_to_dictionaries": false])
     }
 }

Tests/SwiftLintFrameworkTests/CommandTests.swift

@@ -4,6 +4,8 @@ import SourceKittenFramework
 @testable import SwiftLintFramework
 import XCTest
 
+// swiftlint:disable file_length
+
 private extension Command {
     init?(string: String) {
         let nsString = string.bridge()
@@ -234,161 +236,184 @@ class CommandTests: XCTestCase {
 
     // MARK: Superfluous Disable Command Detection
 
-    func testSuperfluousDisableCommands() {
-        XCTAssertEqual(
-            violations(Example("// swiftlint:disable nesting\nprint(123)\n"))[0].ruleIdentifier,
-            "superfluous_disable_command"
-        )
-        XCTAssertEqual(
-            violations(Example("// swiftlint:disable:next nesting\nprint(123)\n"))[0].ruleIdentifier,
-            "superfluous_disable_command"
-        )
-        XCTAssertEqual(
-            violations(Example("print(123) // swiftlint:disable:this nesting\n"))[0].ruleIdentifier,
-            "superfluous_disable_command"
-        )
-        XCTAssertEqual(
-            violations(Example("print(123)\n// swiftlint:disable:previous nesting\n"))[0].ruleIdentifier,
-            "superfluous_disable_command"
-        )
+    func testSuperfluousDisableCommands() async throws {
+        do {
+            let first = try await violations(Example("// swiftlint:disable nesting\nprint(123)\n"))[0]
+            XCTAssertEqual(first.ruleIdentifier, "superfluous_disable_command")
+        }
+        do {
+            let first = try await violations(Example("// swiftlint:disable:next nesting\nprint(123)\n"))[0]
+            XCTAssertEqual(first.ruleIdentifier, "superfluous_disable_command")
+        }
+        do {
+            let first = try await violations(Example("print(123) // swiftlint:disable:this nesting\n"))[0]
+            XCTAssertEqual(first.ruleIdentifier, "superfluous_disable_command")
+        }
+        do {
+            let first = try await violations(Example("print(123)\n// swiftlint:disable:previous nesting\n"))[0]
+            XCTAssertEqual(first.ruleIdentifier, "superfluous_disable_command")
+        }
     }
 
-    func testDisableAllOverridesSuperfluousDisableCommand() {
-        XCTAssert(
-            violations(
+    func testDisableAllOverridesSuperfluousDisableCommand() async throws {
+        do {
+            let violations = try await violations(
                 Example("// swiftlint:disable all\n// swiftlint:disable nesting\nprint(123)\n")
-            ).isEmpty
-        )
-        XCTAssert(
-            violations(
+            )
+            XCTAssertEqual(violations, [])
+        }
+        do {
+            let violations = try await violations(
                 Example("// swiftlint:disable all\n// swiftlint:disable:next nesting\nprint(123)\n")
-            ).isEmpty
-        )
-        XCTAssert(
-            violations(
+            )
+            XCTAssertEqual(violations, [])
+        }
+        do {
+            let violations = try await violations(
                 Example("// swiftlint:disable all\n// swiftlint:disable:this nesting\nprint(123)\n")
-            ).isEmpty
-        )
-        XCTAssert(
-            violations(
+            )
+            XCTAssertEqual(violations, [])
+        }
+        do {
+            let violations = try await violations(
                 Example("// swiftlint:disable all\n// swiftlint:disable:previous nesting\nprint(123)\n")
-            ).isEmpty
-        )
+            )
+            XCTAssertEqual(violations, [])
+        }
     }
 
-    func testSuperfluousDisableCommandsIgnoreDelimiter() {
+    func testSuperfluousDisableCommandsIgnoreDelimiter() async throws {
         let longComment = "Comment with a large number of words that shouldn't register as superfluous"
-        XCTAssertEqual(
-            violations(Example("// swiftlint:disable nesting - \(longComment)\nprint(123)\n"))[0]
-                .ruleIdentifier,
-            "superfluous_disable_command"
-        )
-        XCTAssertEqual(
-            violations(Example("// swiftlint:disable:next nesting - Comment\nprint(123)\n"))[0]
-                .ruleIdentifier,
-            "superfluous_disable_command"
-        )
-        XCTAssertEqual(
-            violations(Example("print(123) // swiftlint:disable:this nesting - Comment\n"))[0]
-                .ruleIdentifier,
-            "superfluous_disable_command"
-        )
-        XCTAssertEqual(
-            violations(Example("print(123)\n// swiftlint:disable:previous nesting - Comment\n"))[0]
-                .ruleIdentifier,
-            "superfluous_disable_command"
-        )
+        do {
+            let first = try await violations(Example("// swiftlint:disable nesting - \(longComment)\nprint(123)\n"))[0]
+            XCTAssertEqual(first.ruleIdentifier, "superfluous_disable_command")
+        }
+        do {
+            let first = try await violations(Example("// swiftlint:disable:next nesting - Comment\nprint(123)\n"))[0]
+            XCTAssertEqual(first.ruleIdentifier, "superfluous_disable_command")
+        }
+        do {
+            let first = try await violations(Example("print(123) // swiftlint:disable:this nesting - Comment\n"))[0]
+            XCTAssertEqual(first.ruleIdentifier, "superfluous_disable_command")
+        }
+        do {
+            let first = try await violations(
+                Example("print(123)\n// swiftlint:disable:previous nesting - Comment\n")
+            )[0]
+            XCTAssertEqual(first.ruleIdentifier, "superfluous_disable_command")
+        }
     }
 
-    func testInvalidDisableCommands() {
-        XCTAssertEqual(
-            violations(Example("// swiftlint:disable nesting_foo\nprint(123)\n"))[0]
-                .ruleIdentifier,
-            "superfluous_disable_command"
-        )
-        XCTAssertEqual(
-            violations(Example("// swiftlint:disable:next nesting_foo\nprint(123)\n"))[0]
-                .ruleIdentifier,
-            "superfluous_disable_command"
-        )
-        XCTAssertEqual(
-            violations(Example("print(123) // swiftlint:disable:this nesting_foo\n"))[0]
-                .ruleIdentifier,
-            "superfluous_disable_command"
-        )
-        XCTAssertEqual(
-            violations(Example("print(123)\n// swiftlint:disable:previous nesting_foo\n"))[0]
-                .ruleIdentifier,
-            "superfluous_disable_command"
-        )
+    func testInvalidDisableCommands() async throws {
+        do {
+            let first = try await violations(Example("// swiftlint:disable nesting_foo\nprint(123)\n"))[0]
+            XCTAssertEqual(first.ruleIdentifier, "superfluous_disable_command")
+        }
+        do {
+            let first = try await violations(Example("// swiftlint:disable:next nesting_foo\nprint(123)\n"))[0]
+            XCTAssertEqual(first.ruleIdentifier, "superfluous_disable_command")
+        }
+        do {
+            let first = try await violations(Example("print(123) // swiftlint:disable:this nesting_foo\n"))[0]
+            XCTAssertEqual(first.ruleIdentifier, "superfluous_disable_command")
+        }
+        do {
+            let first = try await violations(Example("print(123)\n// swiftlint:disable:previous nesting_foo\n"))[0]
+            XCTAssertEqual(first.ruleIdentifier, "superfluous_disable_command")
+        }
 
-        XCTAssertEqual(
-            violations(Example("print(123)\n// swiftlint:disable:previous nesting_foo \n")).count,
-            1
-        )
+        do {
+            let violations = try await violations(Example("print(123)\n// swiftlint:disable:previous nesting_foo \n"))
+            XCTAssertEqual(violations.count, 1)
+        }
 
-        let multipleViolations = violations(Example("// swiftlint:disable nesting this is a comment\n"))
+        let multipleViolations = try await violations(Example("// swiftlint:disable nesting this is a comment\n"))
         XCTAssertEqual(multipleViolations.count, 5)
         XCTAssertTrue(multipleViolations.allSatisfy { $0.ruleIdentifier == "superfluous_disable_command" })
 
-        let onlyNonExistentRulesViolations = violations(Example("// swiftlint:disable this is a comment\n"))
+        let onlyNonExistentRulesViolations = try await violations(Example("// swiftlint:disable this is a comment\n"))
         XCTAssertEqual(onlyNonExistentRulesViolations.count, 4)
         XCTAssertTrue(onlyNonExistentRulesViolations.allSatisfy {
             $0.ruleIdentifier == "superfluous_disable_command"
         })
 
-        XCTAssertEqual(
-            violations(Example("print(123)\n// swiftlint:disable:previous nesting_foo\n"))[0].reason,
-            "'nesting_foo' is not a valid SwiftLint rule; remove it from the disable command"
-        )
+        do {
+            let first = try await violations(Example("print(123)\n// swiftlint:disable:previous nesting_foo\n"))[0]
+            XCTAssertEqual(first.reason,
+                           "'nesting_foo' is not a valid SwiftLint rule; remove it from the disable command")
+        }
 
-        XCTAssertEqual(violations(Example("/* swiftlint:disable nesting */\n")).count, 1)
+        do {
+            let violations = try await violations(Example("/* swiftlint:disable nesting */\n"))
+            XCTAssertEqual(violations.count, 1)
+        }
     }
 
-    func testSuperfluousDisableCommandsDisabled() {
-        XCTAssertEqual(
-            violations(Example("// swiftlint:disable superfluous_disable_command nesting\nprint(123)\n")),
-            []
-        )
-        XCTAssertEqual(
-            violations(Example("// swiftlint:disable superfluous_disable_command\n" +
-                       "// swiftlint:disable nesting\n" +
-                       "print(123)\n")),
-            []
-        )
-        XCTAssertEqual(
-            violations(Example("// swiftlint:disable:next superfluous_disable_command nesting\nprint(123)\n")),
-            []
-        )
-        XCTAssertEqual(
-            violations(Example("print(123) // swiftlint:disable:this superfluous_disable_command nesting\n")),
-            []
-        )
-        XCTAssertEqual(
-            violations(Example("print(123)\n// swiftlint:disable:previous superfluous_disable_command nesting\n")),
-            []
-        )
+    func testSuperfluousDisableCommandsDisabled() async throws {
+        do {
+            let violations = try await violations(
+                Example("// swiftlint:disable superfluous_disable_command nesting\nprint(123)\n")
+            )
+            XCTAssertEqual(violations, [])
+        }
+        do {
+            let violations = try await violations(
+                Example("// swiftlint:disable superfluous_disable_command\n" +
+                        "// swiftlint:disable nesting\n" +
+                        "print(123)\n")
+            )
+            XCTAssertEqual(
+                violations,
+                []
+            )
+        }
+        do {
+            let violations = try await violations(
+                Example("// swiftlint:disable:next superfluous_disable_command nesting\nprint(123)\n")
+            )
+            XCTAssertEqual(violations, [])
+        }
+        do {
+            let violations = try await violations(
+                Example("print(123) // swiftlint:disable:this superfluous_disable_command nesting\n")
+            )
+            XCTAssertEqual(violations, [])
+        }
+        do {
+            let violations = try await violations(
+                Example("print(123)\n// swiftlint:disable:previous superfluous_disable_command nesting\n")
+            )
+            XCTAssertEqual(violations, [])
+        }
     }
 
-    func testSuperfluousDisableCommandsDisabledOnConfiguration() {
+    func testSuperfluousDisableCommandsDisabledOnConfiguration() async throws {
         let rulesMode = Configuration.RulesMode.default(disabled: ["superfluous_disable_command"], optIn: [])
         let configuration = Configuration(rulesMode: rulesMode)
 
-        XCTAssertEqual(
-            violations(Example("// swiftlint:disable nesting\nprint(123)\n"), config: configuration),
-            []
-        )
-        XCTAssertEqual(
-            violations(Example("// swiftlint:disable:next nesting\nprint(123)\n"), config: configuration),
-            []
-        )
-        XCTAssertEqual(
-            violations(Example("print(123) // swiftlint:disable:this nesting\n"), config: configuration),
-            []
-        )
-        XCTAssertEqual(
-            violations(Example("print(123)\n// swiftlint:disable:previous nesting\n"), config: configuration),
-            []
-        )
+        do {
+            let violations = try await violations(
+                Example("// swiftlint:disable nesting\nprint(123)\n"), config: configuration
+            )
+            XCTAssertEqual(violations, [])
+        }
+        do {
+            let violations = try await violations(
+                Example("// swiftlint:disable:next nesting\nprint(123)\n"), config: configuration
+            )
+            XCTAssertEqual(violations, [])
+        }
+        do {
+            let violations = try await violations(
+                Example("print(123) // swiftlint:disable:this nesting\n"), config: configuration
+            )
+            XCTAssertEqual(violations, [])
+        }
+        do {
+            let violations = try await violations(
+                Example("print(123)\n// swiftlint:disable:previous nesting\n"), config: configuration
+            )
+            XCTAssertEqual(violations, [])
+        }
     }
 }

Tests/SwiftLintFrameworkTests/CompilerProtocolInitRuleTests.swift

@@ -4,9 +4,9 @@ import XCTest
 class CompilerProtocolInitRuleTests: XCTestCase {
     private let ruleID = CompilerProtocolInitRule.description.identifier
 
-    func testViolationMessageForExpressibleByIntegerLiteral() throws {
+    func testViolationMessageForExpressibleByIntegerLiteral() async throws {
         let config = try XCTUnwrap(makeConfig(nil, ruleID))
-        let allViolations = violations(Example("let a = NSNumber(integerLiteral: 1)"), config: config)
+        let allViolations = try await violations(Example("let a = NSNumber(integerLiteral: 1)"), config: config)
 
         let compilerProtocolInitViolation = allViolations.first { $0.ruleIdentifier == ruleID }
         let violation = try XCTUnwrap(

Tests/SwiftLintFrameworkTests/ComputedAccessorsOrderRuleTests.swift

@@ -2,7 +2,7 @@
 import XCTest
 
 class ComputedAccessorsOrderRuleTests: XCTestCase {
-    func testSetGetConfiguration() {
+    func testSetGetConfiguration() async throws {
         let nonTriggeringExamples = [
             Example("""
             class Foo {
@@ -36,10 +36,10 @@ class ComputedAccessorsOrderRuleTests: XCTestCase {
             .with(triggeringExamples: triggeringExamples)
             .with(nonTriggeringExamples: nonTriggeringExamples)
 
-        verifyRule(description, ruleConfiguration: ["order": "set_get"])
+        try await verifyRule(description, ruleConfiguration: ["order": "set_get"])
     }
 
-    func testGetSetPropertyReason() {
+    func testGetSetPropertyReason() async throws {
         let example = Example("""
         class Foo {
             var foo: Int {
@@ -53,13 +53,14 @@ class ComputedAccessorsOrderRuleTests: XCTestCase {
         }
         """)
 
+        let ruleViolations = try await ruleViolations(example)
         XCTAssertEqual(
-            ruleViolations(example).first?.reason,
+            ruleViolations.first?.reason,
             "Computed properties should first declare the getter and then the setter"
         )
     }
 
-    func testGetSetSubscriptReason() {
+    func testGetSetSubscriptReason() async throws {
         let example = Example("""
         class Foo {
             subscript(i: Int) -> Int {
@@ -73,13 +74,14 @@ class ComputedAccessorsOrderRuleTests: XCTestCase {
         }
         """)
 
+        let ruleViolations = try await ruleViolations(example)
         XCTAssertEqual(
-            ruleViolations(example).first?.reason,
+            ruleViolations.first?.reason,
             "Computed subscripts should first declare the getter and then the setter"
         )
     }
 
-    func testSetGetPropertyReason() {
+    func testSetGetPropertyReason() async throws {
         let example = Example("""
         class Foo {
             var foo: Int {
@@ -93,13 +95,14 @@ class ComputedAccessorsOrderRuleTests: XCTestCase {
         }
         """)
 
+        let ruleViolations = try await ruleViolations(example, ruleConfiguration: ["order": "set_get"])
         XCTAssertEqual(
-            ruleViolations(example, ruleConfiguration: ["order": "set_get"]).first?.reason,
+            ruleViolations.first?.reason,
             "Computed properties should first declare the setter and then the getter"
         )
     }
 
-    func testSetGetSubscriptReason() {
+    func testSetGetSubscriptReason() async throws {
         let example = Example("""
         class Foo {
             subscript(i: Int) -> Int {
@@ -113,17 +116,18 @@ class ComputedAccessorsOrderRuleTests: XCTestCase {
         }
         """)
 
+        let ruleViolations = try await ruleViolations(example, ruleConfiguration: ["order": "set_get"])
         XCTAssertEqual(
-            ruleViolations(example, ruleConfiguration: ["order": "set_get"]).first?.reason,
+            ruleViolations.first?.reason,
             "Computed subscripts should first declare the setter and then the getter"
         )
     }
 
-    private func ruleViolations(_ example: Example, ruleConfiguration: Any? = nil) -> [StyleViolation] {
+    private func ruleViolations(_ example: Example, ruleConfiguration: Any? = nil) async throws -> [StyleViolation] {
         guard let config = makeConfig(ruleConfiguration, ComputedAccessorsOrderRule.description.identifier) else {
             return []
         }
 
-        return violations(example, config: config)
+        return try await violations(example, config: config)
     }
 }

Tests/SwiftLintFrameworkTests/ConditionalReturnsOnNewlineRuleTests.swift

@@ -2,7 +2,7 @@
 import XCTest
 
 class ConditionalReturnsOnNewlineRuleTests: XCTestCase {
-    func testConditionalReturnsOnNewlineWithIfOnly() {
+    func testConditionalReturnsOnNewlineWithIfOnly() async throws {
         // Test with `if_only` set to true
         let nonTriggeringExamples = [
             Example("guard true else {\n return true\n}"),
@@ -25,6 +25,6 @@ class ConditionalReturnsOnNewlineRuleTests: XCTestCase {
             .with(triggeringExamples: triggeringExamples)
             .with(nonTriggeringExamples: nonTriggeringExamples)
 
-        verifyRule(description, ruleConfiguration: ["if_only": true])
+        try await verifyRule(description, ruleConfiguration: ["if_only": true])
     }
 }

Tests/SwiftLintFrameworkTests/ContainsOverFirstNotNilRuleTests.swift

@@ -2,17 +2,17 @@
 import XCTest
 
 class ContainsOverFirstNotNilRuleTests: XCTestCase {
-    func testFirstReason() {
+    func testFirstReason() async throws {
         let example = Example("↓myList.first { $0 % 2 == 0 } != nil")
-        let violations = self.violations(example)
+        let violations = try await self.violations(example)
 
         XCTAssertEqual(violations.count, 1)
         XCTAssertEqual(violations.first?.reason, "Prefer `contains` over `first(where:) != nil`")
     }
 
-    func testFirstIndexReason() {
+    func testFirstIndexReason() async throws {
         let example = Example("↓myList.firstIndex { $0 % 2 == 0 } != nil")
-        let violations = self.violations(example)
+        let violations = try await self.violations(example)
 
         XCTAssertEqual(violations.count, 1)
         XCTAssertEqual(violations.first?.reason, "Prefer `contains` over `firstIndex(where:) != nil`")
@@ -20,11 +20,11 @@ class ContainsOverFirstNotNilRuleTests: XCTestCase {
 
     // MARK: - Private
 
-    private func violations(_ example: Example, config: Any? = nil) -> [StyleViolation] {
+    private func violations(_ example: Example, config: Any? = nil) async throws -> [StyleViolation] {
         guard let config = makeConfig(config, ContainsOverFirstNotNilRule.description.identifier) else {
             return []
         }
 
-        return SwiftLintFrameworkTests.violations(example, config: config)
+        return try await SwiftLintFrameworkTests.violations(example, config: config)
     }
 }

Tests/SwiftLintFrameworkTests/CustomRulesTests.swift

@@ -99,77 +99,80 @@ class CustomRulesTests: XCTestCase {
         XCTAssertEqual(identifier, "my_custom_rule")
     }
 
-    func testCustomRules() {
+    func testCustomRules() async throws {
         let (regexConfig, customRules) = getCustomRules()
 
         let file = SwiftLintFile(contents: "// My file with\n// a pattern")
-        XCTAssertEqual(customRules.validate(file: file),
+        let violations = try await customRules.validate(file: file)
+        XCTAssertEqual(violations,
                        [StyleViolation(ruleDescription: regexConfig.description,
                                        severity: .warning,
                                        location: Location(file: nil, line: 2, character: 6),
                                        reason: regexConfig.message)])
     }
 
-    func testLocalDisableCustomRule() {
+    func testLocalDisableCustomRule() async throws {
         let (_, customRules) = getCustomRules()
         let file = SwiftLintFile(contents: "//swiftlint:disable custom \n// file with a pattern")
-        XCTAssertEqual(customRules.validate(file: file), [])
+        let violations = try await customRules.validate(file: file)
+        XCTAssertEqual(violations, [])
     }
 
-    func testLocalDisableCustomRuleWithMultipleRules() {
+    func testLocalDisableCustomRuleWithMultipleRules() async throws {
         let (configs, customRules) = getCustomRulesWithTwoRules()
         let file = SwiftLintFile(contents: "//swiftlint:disable \(configs.1.identifier) \n// file with a pattern")
-        XCTAssertEqual(customRules.validate(file: file),
+        let violations = try await customRules.validate(file: file)
+        XCTAssertEqual(violations,
                        [StyleViolation(ruleDescription: configs.0.description,
                                        severity: .warning,
                                        location: Location(file: nil, line: 2, character: 16),
                                        reason: configs.0.message)])
     }
 
-    func testCustomRulesIncludedDefault() {
+    func testCustomRulesIncludedDefault() async throws {
         // Violation detected when included is omitted.
         let (_, customRules) = getCustomRules()
-        let violations = customRules.validate(file: getTestTextFile())
+        let violations = try await customRules.validate(file: getTestTextFile())
         XCTAssertEqual(violations.count, 1)
     }
 
-    func testCustomRulesIncludedExcludesFile() {
+    func testCustomRulesIncludedExcludesFile() async throws {
         var (regexConfig, customRules) = getCustomRules(["included": "\\.yml$"])
 
         var customRuleConfiguration = CustomRulesConfiguration()
         customRuleConfiguration.customRuleConfigurations = [regexConfig]
         customRules.configuration = customRuleConfiguration
 
-        let violations = customRules.validate(file: getTestTextFile())
+        let violations = try await customRules.validate(file: getTestTextFile())
         XCTAssertEqual(violations.count, 0)
     }
 
-    func testCustomRulesExcludedExcludesFile() {
+    func testCustomRulesExcludedExcludesFile() async throws {
         var (regexConfig, customRules) = getCustomRules(["excluded": "\\.txt$"])
 
         var customRuleConfiguration = CustomRulesConfiguration()
         customRuleConfiguration.customRuleConfigurations = [regexConfig]
         customRules.configuration = customRuleConfiguration
 
-        let violations = customRules.validate(file: getTestTextFile())
+        let violations = try await customRules.validate(file: getTestTextFile())
         XCTAssertEqual(violations.count, 0)
     }
 
-    func testCustomRulesExcludedArrayExcludesFile() {
+    func testCustomRulesExcludedArrayExcludesFile() async throws {
         var (regexConfig, customRules) = getCustomRules(["excluded": ["\\.pdf$", "\\.txt$"]])
 
         var customRuleConfiguration = CustomRulesConfiguration()
         customRuleConfiguration.customRuleConfigurations = [regexConfig]
         customRules.configuration = customRuleConfiguration
 
-        let violations = customRules.validate(file: getTestTextFile())
+        let violations = try await customRules.validate(file: getTestTextFile())
         XCTAssertEqual(violations.count, 0)
     }
 
-    func testCustomRulesCaptureGroup() {
+    func testCustomRulesCaptureGroup() async throws {
         let (_, customRules) = getCustomRules(["regex": #"\ba\s+(\w+)"#,
                                                "capture_group": 1])
-        let violations = customRules.validate(file: getTestTextFile())
+        let violations = try await customRules.validate(file: getTestTextFile())
         XCTAssertEqual(violations.count, 1)
         XCTAssertEqual(violations[0].location.line, 2)
         XCTAssertEqual(violations[0].location.character, 6)

Tests/SwiftLintFrameworkTests/CyclomaticComplexityRuleTests.swift

@@ -30,11 +30,12 @@ class CyclomaticComplexityRuleTests: XCTestCase {
         return Example(example)
     }()
 
-    func testCyclomaticComplexity() {
-        verifyRule(CyclomaticComplexityRule.description, commentDoesntViolate: true, stringDoesntViolate: true)
+    func testCyclomaticComplexity() async throws {
+        try await verifyRule(CyclomaticComplexityRule.description, commentDoesntViolate: true,
+                             stringDoesntViolate: true)
     }
 
-    func testIgnoresCaseStatementsConfigurationEnabled() {
+    func testIgnoresCaseStatementsConfigurationEnabled() async throws {
         let baseDescription = CyclomaticComplexityRule.description
         let triggeringExamples = [complexIfExample]
         let nonTriggeringExamples = baseDescription.nonTriggeringExamples + [complexSwitchExample]
@@ -42,11 +43,11 @@ class CyclomaticComplexityRuleTests: XCTestCase {
         let description = baseDescription.with(nonTriggeringExamples: nonTriggeringExamples)
                                          .with(triggeringExamples: triggeringExamples)
 
-        verifyRule(description, ruleConfiguration: ["ignores_case_statements": true],
-                   commentDoesntViolate: true, stringDoesntViolate: true)
+        try await verifyRule(description, ruleConfiguration: ["ignores_case_statements": true],
+                             commentDoesntViolate: true, stringDoesntViolate: true)
     }
 
-    func testIgnoresCaseStatementsConfigurationDisabled() {
+    func testIgnoresCaseStatementsConfigurationDisabled() async throws {
         let baseDescription = CyclomaticComplexityRule.description
         let triggeringExamples = baseDescription.triggeringExamples + [complexSwitchExample]
         let nonTriggeringExamples = baseDescription.nonTriggeringExamples
@@ -54,7 +55,7 @@ class CyclomaticComplexityRuleTests: XCTestCase {
         let description = baseDescription.with(nonTriggeringExamples: nonTriggeringExamples)
                                          .with(triggeringExamples: triggeringExamples)
 
-        verifyRule(description, ruleConfiguration: ["ignores_case_statements": false],
-                   commentDoesntViolate: true, stringDoesntViolate: true)
+        try await verifyRule(description, ruleConfiguration: ["ignores_case_statements": false],
+                             commentDoesntViolate: true, stringDoesntViolate: true)
     }
 }

Tests/SwiftLintFrameworkTests/DeploymentTargetRuleTests.swift

@@ -2,9 +2,9 @@
 import XCTest
 
 class DeploymentTargetRuleTests: XCTestCase {
-    func testMacOSAttributeReason() {
+    func testMacOSAttributeReason() async throws {
         let example = Example("@available(macOS 10.11, *)\nclass A {}")
-        let violations = self.violations(example, config: ["macOS_deployment_target": "10.14.0"])
+        let violations = try await self.violations(example, config: ["macOS_deployment_target": "10.14.0"])
 
         let expectedMessage = "Availability attribute is using a version (10.11) that is satisfied by " +
                               "the deployment target (10.14) for platform macOS"
@@ -12,9 +12,9 @@ class DeploymentTargetRuleTests: XCTestCase {
         XCTAssertEqual(violations.first?.reason, expectedMessage)
     }
 
-    func testWatchOSConditionReason() {
+    func testWatchOSConditionReason() async throws {
         let example = Example("if #available(watchOS 4, *) {}")
-        let violations = self.violations(example, config: ["watchOS_deployment_target": "5.0.1"])
+        let violations = try await self.violations(example, config: ["watchOS_deployment_target": "5.0.1"])
 
         let expectedMessage = "Availability condition is using a version (4) that is satisfied by " +
                               "the deployment target (5.0.1) for platform watchOS"
@@ -22,11 +22,11 @@ class DeploymentTargetRuleTests: XCTestCase {
         XCTAssertEqual(violations.first?.reason, expectedMessage)
     }
 
-    func testiOSNegativeAttributeReason() throws {
+    func testiOSNegativeAttributeReason() async throws {
         try XCTSkipUnless(SwiftVersion.current >= .fiveDotSix)
 
         let example = Example("if #unavailable(iOS 14) { legacyImplementation() }")
-        let violations = self.violations(example, config: ["iOS_deployment_target": "15.0"])
+        let violations = try await self.violations(example, config: ["iOS_deployment_target": "15.0"])
 
         let expectedMessage = "Availability negative condition is using a version (14) that is satisfied by " +
                               "the deployment target (15.0) for platform iOS"
@@ -34,11 +34,11 @@ class DeploymentTargetRuleTests: XCTestCase {
         XCTAssertEqual(violations.first?.reason, expectedMessage)
     }
 
-    private func violations(_ example: Example, config: Any?) -> [StyleViolation] {
+    private func violations(_ example: Example, config: Any?) async throws -> [StyleViolation] {
         guard let config = makeConfig(config, DeploymentTargetRule.description.identifier) else {
             return []
         }
 
-        return SwiftLintFrameworkTests.violations(example, config: config)
+        return try await SwiftLintFrameworkTests.violations(example, config: config)
     }
 }

Tests/SwiftLintFrameworkTests/DisableAllTests.swift

@@ -11,10 +11,11 @@ class DisableAllTests: XCTestCase {
 
     // MARK: Violating Phrase
     /// Tests whether example violating phrases trigger when not applying disable rule
-    func testViolatingPhrase() {
+    func testViolatingPhrase() async throws {
         for violatingPhrase in violatingPhrases {
+            let violations = try await violations(violatingPhrase.with(code: violatingPhrase.code + "\n"))
             XCTAssertEqual(
-                violations(violatingPhrase.with(code: violatingPhrase.code + "\n")).count,
+                violations.count,
                 1,
                 #function,
                 file: violatingPhrase.file,
@@ -24,11 +25,12 @@ class DisableAllTests: XCTestCase {
 
     // MARK: Enable / Disable Base
     /// Tests whether swiftlint:disable all protects properly
-    func testDisableAll() {
+    func testDisableAll() async throws {
         for violatingPhrase in violatingPhrases {
             let protectedPhrase = violatingPhrase.with(code: "// swiftlint:disable all\n" + violatingPhrase.code)
+            let violations = try await violations(protectedPhrase)
             XCTAssertEqual(
-                violations(protectedPhrase).count,
+                violations.count,
                 0,
                 #function,
                 file: violatingPhrase.file,
@@ -37,7 +39,7 @@ class DisableAllTests: XCTestCase {
     }
 
     /// Tests whether swiftlint:enable all unprotects properly
-    func testEnableAll() {
+    func testEnableAll() async throws {
         for violatingPhrase in violatingPhrases {
             let unprotectedPhrase = violatingPhrase.with(code: """
                 // swiftlint:disable all
@@ -45,8 +47,9 @@ class DisableAllTests: XCTestCase {
                 // swiftlint:enable all
                 \(violatingPhrase.code)\n
                 """)
+            let violations = try await violations(unprotectedPhrase)
             XCTAssertEqual(
-                violations(unprotectedPhrase).count,
+                violations.count,
                 1,
                 #function,
                 file: violatingPhrase.file,
@@ -56,15 +59,16 @@ class DisableAllTests: XCTestCase {
 
     // MARK: Enable / Disable Previous
     /// Tests whether swiftlint:disable:previous all protects properly
-    func testDisableAllPrevious() {
+    func testDisableAllPrevious() async throws {
         for violatingPhrase in violatingPhrases {
             let protectedPhrase = violatingPhrase
                 .with(code: """
                     \(violatingPhrase.code)
                     // swiftlint:disable:previous all\n
                     """)
+            let violations = try await violations(protectedPhrase)
             XCTAssertEqual(
-                violations(protectedPhrase).count,
+                violations.count,
                 0,
                 #function,
                 file: violatingPhrase.file,
@@ -73,7 +77,7 @@ class DisableAllTests: XCTestCase {
     }
 
     /// Tests whether swiftlint:enable:previous all unprotects properly
-    func testEnableAllPrevious() {
+    func testEnableAllPrevious() async throws {
         for violatingPhrase in violatingPhrases {
             let unprotectedPhrase = violatingPhrase.with(code: """
                 // swiftlint:disable all
@@ -81,8 +85,9 @@ class DisableAllTests: XCTestCase {
                 \(violatingPhrase.code)
                 // swiftlint:enable:previous all\n
                 """)
+            let violations = try await violations(unprotectedPhrase)
             XCTAssertEqual(
-                violations(unprotectedPhrase).count,
+                violations.count,
                 1,
                 #function,
                 file: violatingPhrase.file,
@@ -92,11 +97,12 @@ class DisableAllTests: XCTestCase {
 
     // MARK: Enable / Disable Next
     /// Tests whether swiftlint:disable:next all protects properly
-    func testDisableAllNext() {
+    func testDisableAllNext() async throws {
         for violatingPhrase in violatingPhrases {
             let protectedPhrase = violatingPhrase.with(code: "// swiftlint:disable:next all\n" + violatingPhrase.code)
+            let violations = try await violations(protectedPhrase)
             XCTAssertEqual(
-                violations(protectedPhrase).count,
+                violations.count,
                 0,
                 #function,
                 file: violatingPhrase.file,
@@ -105,7 +111,7 @@ class DisableAllTests: XCTestCase {
     }
 
     /// Tests whether swiftlint:enable:next all unprotects properly
-    func testEnableAllNext() {
+    func testEnableAllNext() async throws {
         for violatingPhrase in violatingPhrases {
             let unprotectedPhrase = violatingPhrase.with(code: """
                 // swiftlint:disable all
@@ -113,8 +119,9 @@ class DisableAllTests: XCTestCase {
                 // swiftlint:enable:next all
                 \(violatingPhrase.code)\n
                 """)
+            let violations = try await violations(unprotectedPhrase)
             XCTAssertEqual(
-                violations(unprotectedPhrase).count,
+                violations.count,
                 1,
                 #function,
                 file: violatingPhrase.file,
@@ -124,12 +131,13 @@ class DisableAllTests: XCTestCase {
 
     // MARK: Enable / Disable This
     /// Tests whether swiftlint:disable:this all protects properly
-    func testDisableAllThis() {
+    func testDisableAllThis() async throws {
         for violatingPhrase in violatingPhrases {
             let rawViolatingPhrase = violatingPhrase.code.replacingOccurrences(of: "\n", with: "")
             let protectedPhrase = violatingPhrase.with(code: rawViolatingPhrase + "// swiftlint:disable:this all\n")
+            let violations = try await violations(protectedPhrase)
             XCTAssertEqual(
-                violations(protectedPhrase).count,
+                violations.count,
                 0,
                 #function,
                 file: violatingPhrase.file,
@@ -138,7 +146,7 @@ class DisableAllTests: XCTestCase {
     }
 
     /// Tests whether swiftlint:enable:next all unprotects properly
-    func testEnableAllThis() {
+    func testEnableAllThis() async throws {
         for violatingPhrase in violatingPhrases {
             let rawViolatingPhrase = violatingPhrase.code.replacingOccurrences(of: "\n", with: "")
             let unprotectedPhrase = violatingPhrase.with(code: """
@@ -146,8 +154,9 @@ class DisableAllTests: XCTestCase {
                 \(violatingPhrase.code)
                 \(rawViolatingPhrase)// swiftlint:enable:this all\n"
                 """)
+            let violations = try await violations(unprotectedPhrase)
             XCTAssertEqual(
-                violations(unprotectedPhrase).count,
+                violations.count,
                 1,
                 #function,
                 file: violatingPhrase.file,

Tests/SwiftLintFrameworkTests/DiscouragedDirectInitRuleTests.swift

@@ -4,11 +4,11 @@ import XCTest
 class DiscouragedDirectInitRuleTests: XCTestCase {
     private let baseDescription = DiscouragedDirectInitRule.description
 
-    func testDiscouragedDirectInitWithConfiguredSeverity() {
-        verifyRule(baseDescription, ruleConfiguration: ["severity": "error"])
+    func testDiscouragedDirectInitWithConfiguredSeverity() async throws {
+        try await verifyRule(baseDescription, ruleConfiguration: ["severity": "error"])
     }
 
-    func testDiscouragedDirectInitWithNewIncludedTypes() {
+    func testDiscouragedDirectInitWithNewIncludedTypes() async throws {
         let triggeringExamples = [
             Example("let foo = ↓Foo()"),
             Example("let bar = ↓Bar()")
@@ -23,10 +23,10 @@ class DiscouragedDirectInitRuleTests: XCTestCase {
             .with(triggeringExamples: triggeringExamples)
             .with(nonTriggeringExamples: nonTriggeringExamples)
 
-        verifyRule(description, ruleConfiguration: ["types": ["Foo", "Bar"]])
+        try await verifyRule(description, ruleConfiguration: ["types": ["Foo", "Bar"]])
     }
 
-    func testDiscouragedDirectInitWithReplacedTypes() {
+    func testDiscouragedDirectInitWithReplacedTypes() async throws {
         let triggeringExamples = [
             Example("let bundle = ↓Bundle()")
         ]
@@ -39,6 +39,6 @@ class DiscouragedDirectInitRuleTests: XCTestCase {
             .with(triggeringExamples: triggeringExamples)
             .with(nonTriggeringExamples: nonTriggeringExamples)
 
-        verifyRule(description, ruleConfiguration: ["types": ["Bundle"]])
+        try await verifyRule(description, ruleConfiguration: ["types": ["Bundle"]])
     }
 }

Tests/SwiftLintFrameworkTests/DiscouragedObjectLiteralRuleTests.swift

@@ -2,7 +2,7 @@
 import XCTest
 
 class DiscouragedObjectLiteralRuleTests: XCTestCase {
-    func testWithImageLiteral() {
+    func testWithImageLiteral() async throws {
         let baseDescription = DiscouragedObjectLiteralRule.description
         let nonTriggeringExamples = baseDescription.nonTriggeringExamples + [
             Example("let color = #colorLiteral(red: 0.9607843161, green: 0.7058823705, blue: 0.200000003, alpha: 1)")
@@ -14,10 +14,10 @@ class DiscouragedObjectLiteralRuleTests: XCTestCase {
         let description = baseDescription.with(nonTriggeringExamples: nonTriggeringExamples,
                                                triggeringExamples: triggeringExamples)
 
-        verifyRule(description, ruleConfiguration: ["image_literal": true, "color_literal": false])
+        try await verifyRule(description, ruleConfiguration: ["image_literal": true, "color_literal": false])
     }
 
-    func testWithColorLiteral() {
+    func testWithColorLiteral() async throws {
         let baseDescription = DiscouragedObjectLiteralRule.description
         let nonTriggeringExamples = baseDescription.nonTriggeringExamples + [
             Example("let image = #imageLiteral(resourceName: \"image.jpg\")")
@@ -29,6 +29,6 @@ class DiscouragedObjectLiteralRuleTests: XCTestCase {
         let description = baseDescription.with(nonTriggeringExamples: nonTriggeringExamples,
                                                triggeringExamples: triggeringExamples)
 
-        verifyRule(description, ruleConfiguration: ["image_literal": false, "color_literal": true])
+        try await verifyRule(description, ruleConfiguration: ["image_literal": false, "color_literal": true])
     }
 }

Tests/SwiftLintFrameworkTests/EmptyCountRuleTests.swift

@@ -2,7 +2,7 @@
 import XCTest
 
 class EmptyCountRuleTests: XCTestCase {
-    func testEmptyCountWithOnlyAfterDot() {
+    func testEmptyCountWithOnlyAfterDot() async throws {
         // Test with `only_after_dot` set to true
         let nonTriggeringExamples = [
             Example("var count = 0\n"),
@@ -30,6 +30,6 @@ class EmptyCountRuleTests: XCTestCase {
             .with(triggeringExamples: triggeringExamples)
             .with(nonTriggeringExamples: nonTriggeringExamples)
 
-        verifyRule(description, ruleConfiguration: ["only_after_dot": true])
+        try await verifyRule(description, ruleConfiguration: ["only_after_dot": true])
     }
 }

Tests/SwiftLintFrameworkTests/ExpiringTodoRuleTests.swift

@@ -10,49 +10,50 @@ class ExpiringTodoRuleTests: XCTestCase {
         config = makeConfiguration()
     }
 
-    func testExpiringTodo() {
-        verifyRule(ExpiringTodoRule.description, commentDoesntViolate: false)
+    func testExpiringTodo() async throws {
+        try await verifyRule(ExpiringTodoRule.description, commentDoesntViolate: false)
     }
 
-    func testExpiredTodo() {
+    func testExpiredTodo() async throws {
         let example = Example("fatalError() // TODO: [\(dateString(for: .expired))] Implement")
-        let violations = self.violations(example)
+        let violations = try await self.violations(example)
         XCTAssertEqual(violations.count, 1)
         XCTAssertEqual(violations.first!.reason, "TODO/FIXME has expired and must be resolved")
     }
 
-    func testExpiredFixMe() {
+    func testExpiredFixMe() async throws {
         let example = Example("fatalError() // FIXME: [\(dateString(for: .expired))] Implement")
-        let violations = self.violations(example)
+        let violations = try await self.violations(example)
         XCTAssertEqual(violations.count, 1)
         XCTAssertEqual(violations.first!.reason, "TODO/FIXME has expired and must be resolved")
     }
 
-    func testApproachingExpiryTodo() {
+    func testApproachingExpiryTodo() async throws {
         let example = Example("fatalError() // TODO: [\(dateString(for: .approachingExpiry))] Implement")
-        let violations = self.violations(example)
+        let violations = try await self.violations(example)
         XCTAssertEqual(violations.count, 1)
         XCTAssertEqual(violations.first!.reason, "TODO/FIXME is approaching its expiry and should be resolved soon")
     }
 
-    func testNonExpiredTodo() {
+    func testNonExpiredTodo() async throws {
         let example = Example("fatalError() // TODO: [\(dateString(for: nil))] Implement")
-        XCTAssertEqual(violations(example).count, 0)
+        let violations = try await violations(example)
+        XCTAssertEqual(violations, [])
     }
 
-    func testExpiredCustomDelimiters() {
+    func testExpiredCustomDelimiters() async throws {
         let ruleConfig: ExpiringTodoConfiguration = .init(
             dateDelimiters: .init(opening: "<", closing: ">")
         )
         config = makeConfiguration(with: ruleConfig)
 
         let example = Example("fatalError() // TODO: <\(dateString(for: .expired))> Implement")
-        let violations = self.violations(example)
+        let violations = try await self.violations(example)
         XCTAssertEqual(violations.count, 1)
         XCTAssertEqual(violations.first!.reason, "TODO/FIXME has expired and must be resolved")
     }
 
-    func testExpiredCustomSeparator() {
+    func testExpiredCustomSeparator() async throws {
         let ruleConfig: ExpiringTodoConfiguration = .init(
             dateFormat: "MM-dd-yyyy",
             dateSeparator: "-"
@@ -60,31 +61,31 @@ class ExpiringTodoRuleTests: XCTestCase {
         config = makeConfiguration(with: ruleConfig)
 
         let example = Example("fatalError() // TODO: [\(dateString(for: .expired))] Implement")
-        let violations = self.violations(example)
+        let violations = try await self.violations(example)
         XCTAssertEqual(violations.count, 1)
         XCTAssertEqual(violations.first!.reason, "TODO/FIXME has expired and must be resolved")
     }
 
-    func testExpiredCustomFormat() {
+    func testExpiredCustomFormat() async throws {
         let ruleConfig: ExpiringTodoConfiguration = .init(
             dateFormat: "yyyy/MM/dd"
         )
         config = makeConfiguration(with: ruleConfig)
 
         let example = Example("fatalError() // TODO: [\(dateString(for: .expired))] Implement")
-        let violations = self.violations(example)
+        let violations = try await self.violations(example)
         XCTAssertEqual(violations.count, 1)
         XCTAssertEqual(violations.first!.reason, "TODO/FIXME has expired and must be resolved")
     }
 
-    func testMultipleExpiredTodos() {
+    func testMultipleExpiredTodos() async throws {
         let example = Example(
             """
             fatalError() // TODO: [\(dateString(for: .expired))] Implement one
             fatalError() // TODO: Implement two by [\(dateString(for: .expired))]
             """
         )
-        let violations = self.violations(example)
+        let violations = try await self.violations(example)
         XCTAssertEqual(violations.count, 2)
         XCTAssertEqual(violations[0].reason, "TODO/FIXME has expired and must be resolved")
         XCTAssertEqual(violations[0].location.line, 1)
@@ -92,7 +93,7 @@ class ExpiringTodoRuleTests: XCTestCase {
         XCTAssertEqual(violations[1].location.line, 2)
     }
 
-    func testTodoAndExpiredTodo() {
+    func testTodoAndExpiredTodo() async throws {
         let example = Example(
             """
             // TODO: Implement one - without deadline
@@ -100,13 +101,13 @@ class ExpiringTodoRuleTests: XCTestCase {
             // TODO: Implement two by [\(dateString(for: .expired))]
             """
         )
-        let violations = self.violations(example)
+        let violations = try await self.violations(example)
         XCTAssertEqual(violations.count, 1)
         XCTAssertEqual(violations[0].reason, "TODO/FIXME has expired and must be resolved")
         XCTAssertEqual(violations[0].location.line, 3)
     }
 
-    func testMultilineExpiredTodo() {
+    func testMultilineExpiredTodo() async throws {
         let example = Example(
             """
             // TODO: Multi-line task
@@ -115,39 +116,39 @@ class ExpiringTodoRuleTests: XCTestCase {
             //       severity: fatal
             """
         )
-        let violations = self.violations(example)
+        let violations = try await self.violations(example)
         XCTAssertEqual(violations.count, 1)
         XCTAssertEqual(violations[0].reason, "TODO/FIXME has expired and must be resolved")
         XCTAssertEqual(violations[0].location.line, 3)
     }
 
-    func testTodoFunctionAndExpiredTodo() {
+    func testTodoFunctionAndExpiredTodo() async throws {
         let example = Example(
             """
             TODO()
             // TODO: Implement two by [\(dateString(for: .expired))]
             """
         )
-        let violations = self.violations(example)
+        let violations = try await self.violations(example)
         XCTAssertEqual(violations.count, 1)
         XCTAssertEqual(violations[0].reason, "TODO/FIXME has expired and must be resolved")
         XCTAssertEqual(violations[0].location.line, 2)
     }
 
-    func testBadExpiryTodoFormat() throws {
+    func testBadExpiryTodoFormat() async throws {
         let ruleConfig: ExpiringTodoConfiguration = .init(
             dateFormat: "dd/yyyy/MM"
         )
         config = makeConfiguration(with: ruleConfig)
 
         let example = Example("fatalError() // TODO: [31/01/2020] Implement")
-        let violations = self.violations(example)
+        let violations = try await self.violations(example)
         XCTAssertEqual(violations.count, 1)
         XCTAssertEqual(violations.first?.reason, "Expiring TODO/FIXME is incorrectly formatted")
     }
 
-    private func violations(_ example: Example) -> [StyleViolation] {
-        return SwiftLintFrameworkTests.violations(example, config: config)
+    private func violations(_ example: Example) async throws -> [StyleViolation] {
+        return try await SwiftLintFrameworkTests.violations(example, config: config)
     }
 
     private func dateString(for status: ExpiringTodoRule.ExpiryViolationLevel?) -> String {

Tests/SwiftLintFrameworkTests/ExplicitTypeInterfaceRuleTests.swift

@@ -2,7 +2,7 @@
 import XCTest
 
 class ExplicitTypeInterfaceRuleTests: XCTestCase {
-    func testLocalVars() {
+    func testLocalVars() async throws {
         let nonTriggeringExamples = [
             Example("func foo() {\nlet intVal: Int = 1\n}"),
             Example("""
@@ -27,10 +27,10 @@ class ExplicitTypeInterfaceRuleTests: XCTestCase {
             .with(triggeringExamples: triggeringExamples)
             .with(nonTriggeringExamples: nonTriggeringExamples)
 
-        verifyRule(description)
+        try await verifyRule(description)
     }
 
-    func testExcludeLocalVars() {
+    func testExcludeLocalVars() async throws {
         let nonTriggeringExamples = ExplicitTypeInterfaceRule.description.nonTriggeringExamples + [
             Example("func foo() {\nlet intVal = 1\n}")
         ]
@@ -39,10 +39,10 @@ class ExplicitTypeInterfaceRuleTests: XCTestCase {
             .with(triggeringExamples: triggeringExamples)
             .with(nonTriggeringExamples: nonTriggeringExamples)
 
-        verifyRule(description, ruleConfiguration: ["excluded": ["local"]])
+        try await verifyRule(description, ruleConfiguration: ["excluded": ["local"]])
     }
 
-    func testExcludeClassVars() {
+    func testExcludeClassVars() async throws {
         let nonTriggeringExamples = ExplicitTypeInterfaceRule.description.nonTriggeringExamples + [
             Example("class Foo {\n  static var myStaticVar = 0\n}\n"),
             Example("class Foo {\n  static let myStaticLet = 0\n}\n")
@@ -56,10 +56,10 @@ class ExplicitTypeInterfaceRuleTests: XCTestCase {
             .with(triggeringExamples: triggeringExamples)
             .with(nonTriggeringExamples: nonTriggeringExamples)
 
-        verifyRule(description, ruleConfiguration: ["excluded": ["static"]])
+        try await verifyRule(description, ruleConfiguration: ["excluded": ["static"]])
     }
 
-    func testAllowRedundancy() {
+    func testAllowRedundancy() async throws {
         let nonTriggeringExamples: [Example] = [
             Example("class Foo {\n  var myVar: Int? = 0\n}\n"),
             Example("class Foo {\n  let myVar: Int? = 0\n}\n"),
@@ -87,10 +87,10 @@ class ExplicitTypeInterfaceRuleTests: XCTestCase {
             .with(triggeringExamples: triggeringExamples)
             .with(nonTriggeringExamples: nonTriggeringExamples)
 
-        verifyRule(description, ruleConfiguration: ["allow_redundancy": true])
+        try await verifyRule(description, ruleConfiguration: ["allow_redundancy": true])
     }
 
-    func testEmbeddedInStatements() {
+    func testEmbeddedInStatements() async throws {
         let nonTriggeringExamples = [
             Example("""
             func foo() {
@@ -114,10 +114,10 @@ class ExplicitTypeInterfaceRuleTests: XCTestCase {
             .with(triggeringExamples: triggeringExamples)
             .with(nonTriggeringExamples: nonTriggeringExamples)
 
-        verifyRule(description)
+        try await verifyRule(description)
     }
 
-    func testCaptureGroup() {
+    func testCaptureGroup() async throws {
         let nonTriggeringExamples = [
             Example("""
             var k: Int = 0
@@ -147,10 +147,10 @@ class ExplicitTypeInterfaceRuleTests: XCTestCase {
             .with(triggeringExamples: triggeringExamples)
             .with(nonTriggeringExamples: nonTriggeringExamples)
 
-        verifyRule(description)
+        try await verifyRule(description)
     }
 
-    func testFastEnumerationDeclaration() {
+    func testFastEnumerationDeclaration() async throws {
         let nonTriggeringExaples = [
             Example("""
             func foo() {
@@ -170,10 +170,10 @@ class ExplicitTypeInterfaceRuleTests: XCTestCase {
         let description = ExplicitTypeInterfaceRule.description
             .with(triggeringExamples: triggeringExamples)
             .with(nonTriggeringExamples: nonTriggeringExaples)
-        verifyRule(description)
+        try await verifyRule(description)
     }
 
-    func testSwitchCaseDeclarations() {
+    func testSwitchCaseDeclarations() async throws {
         let nonTriggeringExamples = [
             Example("""
             enum Foo {
@@ -233,6 +233,6 @@ class ExplicitTypeInterfaceRuleTests: XCTestCase {
         let description = ExplicitTypeInterfaceRule.description
             .with(triggeringExamples: triggeringExamples)
             .with(nonTriggeringExamples: nonTriggeringExamples)
-        verifyRule(description)
+        try await verifyRule(description)
     }
 }

Tests/SwiftLintFrameworkTests/FileHeaderRuleTests.swift

@@ -4,17 +4,17 @@ import XCTest
 private let fixturesDirectory = "\(TestResources.path)/FileHeaderRuleFixtures"
 
 class FileHeaderRuleTests: XCTestCase {
-    private func validate(fileName: String, using configuration: Any) throws -> [StyleViolation] {
+    private func validate(fileName: String, using configuration: Any) async throws -> [StyleViolation] {
         let file = SwiftLintFile(path: fixturesDirectory.stringByAppendingPathComponent(fileName))!
         let rule = try FileHeaderRule(configuration: configuration)
-        return rule.validate(file: file)
+        return try await rule.validate(file: file)
     }
 
-    func testFileHeaderWithDefaultConfiguration() {
-        verifyRule(FileHeaderRule.description, skipCommentTests: true)
+    func testFileHeaderWithDefaultConfiguration() async throws {
+        try await verifyRule(FileHeaderRule.description, skipCommentTests: true)
     }
 
-    func testFileHeaderWithRequiredString() {
+    func testFileHeaderWithRequiredString() async throws {
         let nonTriggeringExamples = [
             Example("// **Header"),
             Example("//\n// **Header")
@@ -30,12 +30,12 @@ class FileHeaderRuleTests: XCTestCase {
             .with(nonTriggeringExamples: nonTriggeringExamples)
             .with(triggeringExamples: triggeringExamples)
 
-        verifyRule(description, ruleConfiguration: ["required_string": "**Header"],
-                   stringDoesntViolate: false, skipCommentTests: true,
-                   testMultiByteOffsets: false, testShebang: false)
+        try await verifyRule(description, ruleConfiguration: ["required_string": "**Header"],
+                             stringDoesntViolate: false, skipCommentTests: true,
+                             testMultiByteOffsets: false, testShebang: false)
     }
 
-    func testFileHeaderWithRequiredPattern() {
+    func testFileHeaderWithRequiredPattern() async throws {
         let nonTriggeringExamples = [
             Example("// Copyright © 2016 Realm"),
             Example("//\n// Copyright © 2016 Realm)")
@@ -49,12 +49,12 @@ class FileHeaderRuleTests: XCTestCase {
             .with(nonTriggeringExamples: nonTriggeringExamples)
             .with(triggeringExamples: triggeringExamples)
 
-        verifyRule(description, ruleConfiguration: ["required_pattern": "\\d{4} Realm"],
-                   stringDoesntViolate: false, skipCommentTests: true,
-                   testMultiByteOffsets: false)
+        try await verifyRule(description, ruleConfiguration: ["required_pattern": "\\d{4} Realm"],
+                             stringDoesntViolate: false, skipCommentTests: true,
+                             testMultiByteOffsets: false)
     }
 
-    func testFileHeaderWithRequiredStringAndURLComment() {
+    func testFileHeaderWithRequiredStringAndURLComment() async throws {
         let nonTriggeringExamples = [
             Example("/* Check this url: https://github.com/realm/SwiftLint */")
         ]
@@ -66,12 +66,12 @@ class FileHeaderRuleTests: XCTestCase {
             .with(triggeringExamples: triggeringExamples)
 
         let config = ["required_string": "/* Check this url: https://github.com/realm/SwiftLint */"]
-        verifyRule(description, ruleConfiguration: config,
-                   stringDoesntViolate: false, skipCommentTests: true,
-                   testMultiByteOffsets: false)
+        try await verifyRule(description, ruleConfiguration: config,
+                             stringDoesntViolate: false, skipCommentTests: true,
+                             testMultiByteOffsets: false)
     }
 
-    func testFileHeaderWithForbiddenString() {
+    func testFileHeaderWithForbiddenString() async throws {
         let nonTriggeringExamples = [
             Example("// Copyright\n"),
             Example("let foo = \"**All rights reserved.\""),
@@ -87,11 +87,11 @@ class FileHeaderRuleTests: XCTestCase {
             .with(nonTriggeringExamples: nonTriggeringExamples)
             .with(triggeringExamples: triggeringExamples)
 
-        verifyRule(description, ruleConfiguration: ["forbidden_string": "**All rights reserved."],
-                   skipCommentTests: true)
+        try await verifyRule(description, ruleConfiguration: ["forbidden_string": "**All rights reserved."],
+                             skipCommentTests: true)
     }
 
-    func testFileHeaderWithForbiddenPattern() {
+    func testFileHeaderWithForbiddenPattern() async throws {
         let nonTriggeringExamples = [
             Example("// Copyright\n"),
             Example("// FileHeaderRuleTests.m\n"),
@@ -107,11 +107,11 @@ class FileHeaderRuleTests: XCTestCase {
             .with(nonTriggeringExamples: nonTriggeringExamples)
             .with(triggeringExamples: triggeringExamples)
 
-        verifyRule(description, ruleConfiguration: ["forbidden_pattern": "\\s\\w+\\.swift"],
-                   skipCommentTests: true)
+        try await verifyRule(description, ruleConfiguration: ["forbidden_pattern": "\\s\\w+\\.swift"],
+                             skipCommentTests: true)
     }
 
-    func testFileHeaderWithForbiddenPatternAndDocComment() {
+    func testFileHeaderWithForbiddenPatternAndDocComment() async throws {
         let nonTriggeringExamples = [
             Example("/// This is great tool with tests.\nclass GreatTool {}"),
             Example("class GreatTool {}")
@@ -124,64 +124,127 @@ class FileHeaderRuleTests: XCTestCase {
             .with(nonTriggeringExamples: nonTriggeringExamples)
             .with(triggeringExamples: triggeringExamples)
 
-        verifyRule(description, ruleConfiguration: ["forbidden_pattern": "[tT]ests"],
-                   skipCommentTests: true, testMultiByteOffsets: false)
+        try await verifyRule(description, ruleConfiguration: ["forbidden_pattern": "[tT]ests"],
+                             skipCommentTests: true, testMultiByteOffsets: false)
     }
 
-    func testFileHeaderWithRequiredStringUsingFilenamePlaceholder() {
+    func testFileHeaderWithRequiredStringUsingFilenamePlaceholder() async throws {
         let configuration = ["required_string": "// SWIFTLINT_CURRENT_FILENAME"]
 
         // Non triggering tests
-        XCTAssert(try validate(fileName: "FileNameMatchingSimple.swift", using: configuration).isEmpty)
+        do {
+            let violations = try await validate(fileName: "FileNameMatchingSimple.swift", using: configuration)
+            XCTAssert(violations.isEmpty)
+        }
 
         // Triggering tests
-        XCTAssertEqual(try validate(fileName: "FileNameCaseMismatch.swift", using: configuration).count, 1)
-        XCTAssertEqual(try validate(fileName: "FileNameMismatch.swift", using: configuration).count, 1)
-        XCTAssertEqual(try validate(fileName: "FileNameMissing.swift", using: configuration).count, 1)
+        do {
+            let violations = try await validate(fileName: "FileNameCaseMismatch.swift", using: configuration)
+            XCTAssertEqual(violations.count, 1)
+        }
+        do {
+            let violations = try await validate(fileName: "FileNameMismatch.swift", using: configuration)
+            XCTAssertEqual(violations.count, 1)
+        }
+        do {
+            let violations = try await validate(fileName: "FileNameMissing.swift", using: configuration)
+            XCTAssertEqual(violations.count, 1)
+        }
     }
 
-    func testFileHeaderWithForbiddenStringUsingFilenamePlaceholder() {
+    func testFileHeaderWithForbiddenStringUsingFilenamePlaceholder() async throws {
         let configuration = ["forbidden_string": "// SWIFTLINT_CURRENT_FILENAME"]
 
         // Non triggering tests
-        XCTAssert(try validate(fileName: "FileNameCaseMismatch.swift", using: configuration).isEmpty)
-        XCTAssert(try validate(fileName: "FileNameMismatch.swift", using: configuration).isEmpty)
-        XCTAssert(try validate(fileName: "FileNameMissing.swift", using: configuration).isEmpty)
+        do {
+            let violations = try await validate(fileName: "FileNameCaseMismatch.swift", using: configuration)
+            XCTAssert(violations.isEmpty)
+        }
+        do {
+            let violations = try await validate(fileName: "FileNameMismatch.swift", using: configuration)
+            XCTAssert(violations.isEmpty)
+        }
+        do {
+            let violations = try await validate(fileName: "FileNameMissing.swift", using: configuration)
+            XCTAssert(violations.isEmpty)
+        }
 
         // Triggering tests
-        XCTAssertEqual(try validate(fileName: "FileNameMatchingSimple.swift", using: configuration).count, 1)
+        do {
+            let violations = try await validate(fileName: "FileNameMatchingSimple.swift", using: configuration)
+            XCTAssertEqual(violations.count, 1)
+        }
     }
 
-    func testFileHeaderWithRequiredPatternUsingFilenamePlaceholder() {
+    func testFileHeaderWithRequiredPatternUsingFilenamePlaceholder() async throws {
         let configuration1 = ["required_pattern": "// SWIFTLINT_CURRENT_FILENAME\n.*\\d{4}"]
         let configuration2 = ["required_pattern":
             "// Copyright © \\d{4}\n// File: \"SWIFTLINT_CURRENT_FILENAME\""]
 
         // Non triggering tests
-        XCTAssert(try validate(fileName: "FileNameMatchingSimple.swift", using: configuration1).isEmpty)
-        XCTAssert(try validate(fileName: "FileNameMatchingComplex.swift", using: configuration2).isEmpty)
+        do {
+            let violations = try await validate(fileName: "FileNameMatchingSimple.swift", using: configuration1)
+            XCTAssert(violations.isEmpty)
+        }
+        do {
+            let violations = try await validate(fileName: "FileNameMatchingComplex.swift", using: configuration2)
+            XCTAssert(violations.isEmpty)
+        }
 
         // Triggering tests
-        XCTAssertEqual(try validate(fileName: "FileNameCaseMismatch.swift", using: configuration1).count, 1)
-        XCTAssertEqual(try validate(fileName: "FileNameMismatch.swift", using: configuration1).count, 1)
-        XCTAssertEqual(try validate(fileName: "FileNameMissing.swift", using: configuration1).count, 1)
+        do {
+            let violations = try await validate(fileName: "FileNameCaseMismatch.swift", using: configuration1)
+            XCTAssertEqual(violations.count, 1)
+        }
+        do {
+            let violations = try await validate(fileName: "FileNameMismatch.swift", using: configuration1)
+            XCTAssertEqual(violations.count, 1)
+        }
+        do {
+            let violations = try await validate(fileName: "FileNameMissing.swift", using: configuration1)
+            XCTAssertEqual(violations.count, 1)
+        }
     }
 
-    func testFileHeaderWithForbiddenPatternUsingFilenamePlaceholder() {
+    func testFileHeaderWithForbiddenPatternUsingFilenamePlaceholder() async throws {
         let configuration1 = ["forbidden_pattern": "// SWIFTLINT_CURRENT_FILENAME\n.*\\d{4}"]
         let configuration2 = ["forbidden_pattern": "//.*(\\s|\")SWIFTLINT_CURRENT_FILENAME(\\s|\").*"]
 
         // Non triggering tests
-        XCTAssert(try validate(fileName: "FileNameCaseMismatch.swift", using: configuration1).isEmpty)
-        XCTAssert(try validate(fileName: "FileNameMismatch.swift", using: configuration1).isEmpty)
-        XCTAssert(try validate(fileName: "FileNameMissing.swift", using: configuration1).isEmpty)
+        do {
+            let violations = try await validate(fileName: "FileNameCaseMismatch.swift", using: configuration1)
+            XCTAssert(violations.isEmpty)
+        }
+        do {
+            let violations = try await validate(fileName: "FileNameMismatch.swift", using: configuration1)
+            XCTAssert(violations.isEmpty)
+        }
+        do {
+            let violations = try await validate(fileName: "FileNameMissing.swift", using: configuration1)
+            XCTAssert(violations.isEmpty)
+        }
 
-        XCTAssert(try validate(fileName: "FileNameCaseMismatch.swift", using: configuration2).isEmpty)
-        XCTAssert(try validate(fileName: "FileNameMismatch.swift", using: configuration2).isEmpty)
-        XCTAssert(try validate(fileName: "FileNameMissing.swift", using: configuration2).isEmpty)
+        do {
+            let violations = try await validate(fileName: "FileNameCaseMismatch.swift", using: configuration2)
+            XCTAssert(violations.isEmpty)
+        }
+        do {
+            let violations = try await validate(fileName: "FileNameMismatch.swift", using: configuration2)
+            XCTAssert(violations.isEmpty)
+        }
+        do {
+            let violations = try await validate(fileName: "FileNameMissing.swift", using: configuration2)
+            XCTAssert(violations.isEmpty)
+        }
 
         // Triggering tests
-        XCTAssertEqual(try validate(fileName: "FileNameMatchingSimple.swift", using: configuration1).count, 1)
-        XCTAssertEqual(try validate(fileName: "FileNameMatchingComplex.swift", using: configuration2).count, 1)
+        do {
+            let violations = try await validate(fileName: "FileNameMatchingSimple.swift", using: configuration1)
+            XCTAssertEqual(violations.count, 1)
+        }
+        do {
+            let violations = try await validate(fileName: "FileNameMatchingComplex.swift", using: configuration2)
+            XCTAssertEqual(violations.count, 1)
+        }
     }
 }

Tests/SwiftLintFrameworkTests/FileLengthRuleTests.swift

@@ -2,12 +2,12 @@
 import XCTest
 
 class FileLengthRuleTests: XCTestCase {
-    func testFileLengthWithDefaultConfiguration() {
-        verifyRule(FileLengthRule.description, commentDoesntViolate: false,
-                   testMultiByteOffsets: false, testShebang: false)
+    func testFileLengthWithDefaultConfiguration() async throws {
+        try await verifyRule(FileLengthRule.description, commentDoesntViolate: false,
+                             testMultiByteOffsets: false, testShebang: false)
     }
 
-    func testFileLengthIgnoringLinesWithOnlyComments() {
+    func testFileLengthIgnoringLinesWithOnlyComments() async throws {
         let triggeringExamples = [
             Example(repeatElement("print(\"swiftlint\")\n", count: 401).joined())
         ]
@@ -21,7 +21,7 @@ class FileLengthRuleTests: XCTestCase {
             .with(nonTriggeringExamples: nonTriggeringExamples)
             .with(triggeringExamples: triggeringExamples)
 
-        verifyRule(description, ruleConfiguration: ["ignore_comment_only_lines": true],
-                   testMultiByteOffsets: false, testShebang: false)
+        try await verifyRule(description, ruleConfiguration: ["ignore_comment_only_lines": true],
+                             testMultiByteOffsets: false, testShebang: false)
     }
 }

Tests/SwiftLintFrameworkTests/FileNameRuleTests.swift

@@ -6,7 +6,7 @@ private let fixturesDirectory = "\(TestResources.path)/FileNameRuleFixtures"
 class FileNameRuleTests: XCTestCase {
     private func validate(fileName: String, excludedOverride: [String]? = nil,
                           prefixPattern: String? = nil, suffixPattern: String? = nil,
-                          nestedTypeSeparator: String? = nil) throws -> [StyleViolation] {
+                          nestedTypeSeparator: String? = nil) async throws -> [StyleViolation] {
         let file = SwiftLintFile(path: fixturesDirectory.stringByAppendingPathComponent(fileName))!
         let rule: FileNameRule
         if let excluded = excludedOverride {
@@ -23,81 +23,124 @@ class FileNameRuleTests: XCTestCase {
             rule = FileNameRule()
         }
 
-        return rule.validate(file: file)
+        return try await rule.validate(file: file)
     }
 
-    func testMainDoesntTrigger() {
-        XCTAssert(try validate(fileName: "main.swift").isEmpty)
+    func testMainDoesntTrigger() async throws {
+        let violations = try await validate(fileName: "main.swift")
+        XCTAssert(violations.isEmpty)
     }
 
-    func testLinuxMainDoesntTrigger() {
-        XCTAssert(try validate(fileName: "LinuxMain.swift").isEmpty)
+    func testLinuxMainDoesntTrigger() async throws {
+        let violations = try await validate(fileName: "LinuxMain.swift")
+        XCTAssert(violations.isEmpty)
     }
 
-    func testClassNameDoesntTrigger() {
-        XCTAssert(try validate(fileName: "MyClass.swift").isEmpty)
+    func testClassNameDoesntTrigger() async throws {
+        let violations = try await validate(fileName: "MyClass.swift")
+        XCTAssert(violations.isEmpty)
     }
 
-    func testStructNameDoesntTrigger() {
-        XCTAssert(try validate(fileName: "MyStruct.swift").isEmpty)
+    func testStructNameDoesntTrigger() async throws {
+        let violations = try await validate(fileName: "MyStruct.swift")
+        XCTAssert(violations.isEmpty)
     }
 
-    func testExtensionNameDoesntTrigger() {
-        XCTAssert(try validate(fileName: "NSString+Extension.swift").isEmpty)
+    func testExtensionNameDoesntTrigger() async throws {
+        let violations = try await validate(fileName: "NSString+Extension.swift")
+        XCTAssert(violations.isEmpty)
     }
 
-    func testNestedExtensionDoesntTrigger() {
-        XCTAssert(try validate(fileName: "Notification.Name+Extension.swift").isEmpty)
+    func testNestedExtensionDoesntTrigger() async throws {
+        let violations = try await validate(fileName: "Notification.Name+Extension.swift")
+        XCTAssert(violations.isEmpty)
     }
 
-    func testNestedTypeSeparatorDoesntTrigger() {
-        XCTAssert(try validate(fileName: "NotificationName+Extension.swift", nestedTypeSeparator: "").isEmpty)
-        XCTAssert(try validate(fileName: "Notification__Name+Extension.swift", nestedTypeSeparator: "__").isEmpty)
+    func testNestedTypeSeparatorDoesntTrigger() async throws {
+        do {
+            let violations = try await validate(fileName: "NotificationName+Extension.swift",
+                                                nestedTypeSeparator: "")
+            XCTAssert(violations.isEmpty)
+        }
+        do {
+            let violations = try await validate(fileName: "Notification__Name+Extension.swift",
+                                                nestedTypeSeparator: "__")
+            XCTAssert(violations.isEmpty)
+        }
     }
 
-    func testWrongNestedTypeSeparatorDoesTrigger() {
-        XCTAssert(try !validate(fileName: "Notification__Name+Extension.swift", nestedTypeSeparator: ".").isEmpty)
-        XCTAssert(try !validate(fileName: "NotificationName+Extension.swift", nestedTypeSeparator: "__").isEmpty)
+    func testWrongNestedTypeSeparatorDoesTrigger() async throws {
+        do {
+            let violations = try await validate(fileName: "Notification__Name+Extension.swift",
+                                                nestedTypeSeparator: ".")
+            XCTAssert(!violations.isEmpty)
+        }
+        do {
+            let violations = try await validate(fileName: "NotificationName+Extension.swift",
+                                                nestedTypeSeparator: "__")
+            XCTAssert(!violations.isEmpty)
+        }
     }
 
-    func testMisspelledNameDoesTrigger() {
-        XCTAssertEqual(try validate(fileName: "MyStructf.swift").count, 1)
+    func testMisspelledNameDoesTrigger() async throws {
+        let violations = try await validate(fileName: "MyStructf.swift")
+        XCTAssertEqual(violations.count, 1)
     }
 
-    func testMisspelledNameDoesntTriggerWithOverride() {
-        XCTAssert(try validate(fileName: "MyStructf.swift", excludedOverride: ["MyStructf.swift"]).isEmpty)
+    func testMisspelledNameDoesntTriggerWithOverride() async throws {
+        let violations = try await validate(fileName: "MyStructf.swift", excludedOverride: ["MyStructf.swift"])
+        XCTAssert(violations.isEmpty)
     }
 
-    func testMainDoesTriggerWithoutOverride() {
-        XCTAssertEqual(try validate(fileName: "main.swift", excludedOverride: []).count, 1)
+    func testMainDoesTriggerWithoutOverride() async throws {
+        let violations = try await validate(fileName: "main.swift", excludedOverride: [])
+        XCTAssertEqual(violations.count, 1)
     }
 
-    func testCustomSuffixPattern() {
-        XCTAssert(try validate(fileName: "BoolExtension.swift", suffixPattern: "Extensions?").isEmpty)
-        XCTAssert(try validate(fileName: "BoolExtensions.swift", suffixPattern: "Extensions?").isEmpty)
-        XCTAssert(try validate(fileName: "BoolExtensionTests.swift", suffixPattern: "Extensions?|\\+.*").isEmpty)
+    func testCustomSuffixPattern() async throws {
+        do {
+            let violations = try await validate(fileName: "BoolExtension.swift", suffixPattern: "Extensions?")
+            XCTAssert(violations.isEmpty)
+        }
+        do {
+            let violations = try await validate(fileName: "BoolExtensions.swift", suffixPattern: "Extensions?")
+            XCTAssert(violations.isEmpty)
+        }
+        do {
+            let violations = try await validate(fileName: "BoolExtensionTests.swift",
+                                                suffixPattern: "Extensions?|\\+.*")
+            XCTAssert(violations.isEmpty)
+        }
     }
 
-    func testCustomPrefixPattern() {
-        XCTAssert(try validate(fileName: "ExtensionBool.swift", prefixPattern: "Extensions?").isEmpty)
-        XCTAssert(try validate(fileName: "ExtensionsBool.swift", prefixPattern: "Extensions?").isEmpty)
+    func testCustomPrefixPattern() async throws {
+        do {
+            let violations = try await validate(fileName: "ExtensionBool.swift", prefixPattern: "Extensions?")
+            XCTAssert(violations.isEmpty)
+        }
+        do {
+            let violations = try await validate(fileName: "ExtensionsBool.swift", prefixPattern: "Extensions?")
+            XCTAssert(violations.isEmpty)
+        }
     }
 
-    func testCustomPrefixAndSuffixPatterns() {
-        XCTAssert(
-            try validate(
+    func testCustomPrefixAndSuffixPatterns() async throws {
+        do {
+            let violations = try await validate(
                 fileName: "SLBoolExtension.swift",
                 prefixPattern: "SL",
                 suffixPattern: "Extensions?|\\+.*"
-            ).isEmpty
-        )
+            )
+            XCTAssertEqual(violations, [])
+        }
 
-        XCTAssert(
-            try validate(
+        do {
+            let violations = try await validate(
                 fileName: "ExtensionBool+SwiftLint.swift",
                 prefixPattern: "Extensions?",
                 suffixPattern: "Extensions?|\\+.*"
-            ).isEmpty
-        )
+            )
+            XCTAssertEqual(violations, [])
+        }
     }
 }

Tests/SwiftLintFrameworkTests/FileTypesOrderRuleTests.swift

@@ -3,7 +3,7 @@ import XCTest
 
 class FileTypesOrderRuleTests: XCTestCase {
     // swiftlint:disable:next function_body_length
-    func testFileTypesOrderReversedOrder() {
+    func testFileTypesOrderReversedOrder() async throws {
         // Test with reversed `order` entries
         let nonTriggeringExamples = [
             Example(FileTypesOrderRuleExamples.defaultOrderParts.reversed().joined(separator: "\n\n"))
@@ -74,7 +74,7 @@ class FileTypesOrderRuleTests: XCTestCase {
             .with(triggeringExamples: triggeringExamples)
             .with(nonTriggeringExamples: nonTriggeringExamples)
 
-        verifyRule(
+        try await verifyRule(
             reversedOrderDescription,
             ruleConfiguration: [
                 "order": ["library_content_provider", "preview_provider", "extension", "main_type", "supporting_type"]
@@ -82,7 +82,7 @@ class FileTypesOrderRuleTests: XCTestCase {
         )
     }
 
-    func testFileTypesOrderGroupedOrder() {
+    func testFileTypesOrderGroupedOrder() async throws {
         // Test with grouped `order` entries
         let nonTriggeringExamples = [
             Example("""
@@ -140,7 +140,7 @@ class FileTypesOrderRuleTests: XCTestCase {
             .with(triggeringExamples: triggeringExamples)
             .with(nonTriggeringExamples: nonTriggeringExamples)
 
-        verifyRule(
+        try await verifyRule(
             groupedOrderDescription,
             ruleConfiguration: [
                 "order": ["main_type", ["extension", "supporting_type"], "preview_provider"]

Tests/SwiftLintFrameworkTests/FunctionBodyLengthRuleTests.swift

@@ -14,76 +14,121 @@ private func violatingFuncWithBody(_ body: String, file: StaticString = #file, l
 }
 
 class FunctionBodyLengthRuleTests: XCTestCase {
-    func testFunctionBodyLengths() {
-        let longFunctionBody = funcWithBody(repeatElement("x = 0\n", count: 49).joined())
-        XCTAssertEqual(self.violations(longFunctionBody), [])
+    func testFunctionBodyLengths() async throws {
+        do {
+            let longFunctionBody = funcWithBody(repeatElement("x = 0\n", count: 49).joined())
+            let violations = try await self.violations(longFunctionBody)
+            XCTAssertEqual(violations, [])
+        }
 
-        let longerFunctionBody = violatingFuncWithBody(repeatElement("x = 0\n", count: 51).joined())
-        XCTAssertEqual(self.violations(longerFunctionBody), [StyleViolation(
-            ruleDescription: FunctionBodyLengthRule.description,
-            location: Location(file: nil, line: 1, character: 6),
-            reason: "Function body should span 50 lines or less excluding comments and " +
-            "whitespace: currently spans 51 lines")])
+        do {
+            let longerFunctionBody = violatingFuncWithBody(repeatElement("x = 0\n", count: 51).joined())
+            let violations = try await self.violations(longerFunctionBody)
+            XCTAssertEqual(violations, [StyleViolation(
+                ruleDescription: FunctionBodyLengthRule.description,
+                location: Location(file: nil, line: 1, character: 6),
+                reason: "Function body should span 50 lines or less excluding comments and " +
+                "whitespace: currently spans 51 lines")])
+        }
 
-        let longerFunctionBodyWithEmptyLines = funcWithBody(
-            repeatElement("\n", count: 100).joined()
-        )
-        XCTAssertEqual(self.violations(longerFunctionBodyWithEmptyLines), [])
+        do {
+            let longerFunctionBodyWithEmptyLines = funcWithBody(
+                repeatElement("\n", count: 100).joined()
+            )
+            let violations = try await self.violations(longerFunctionBodyWithEmptyLines)
+            XCTAssertEqual(violations, [])
+        }
     }
 
-    func testFunctionBodyLengthsWithComments() {
-        let longFunctionBodyWithComments = funcWithBody(
-            repeatElement("x = 0\n", count: 49).joined() +
-            "// comment only line should be ignored.\n"
-        )
-        XCTAssertEqual(violations(longFunctionBodyWithComments), [])
+    func testFunctionBodyLengthsWithComments() async throws {
+        do {
+            let longFunctionBodyWithComments = funcWithBody(
+                repeatElement("x = 0\n", count: 49).joined() +
+                "// comment only line should be ignored.\n"
+            )
+            let violations = try await violations(longFunctionBodyWithComments)
+            XCTAssertEqual(violations, [])
+        }
 
-        let longerFunctionBodyWithComments = violatingFuncWithBody(
-            repeatElement("x = 0\n", count: 51).joined() +
-            "// comment only line should be ignored.\n"
-        )
-        XCTAssertEqual(self.violations(longerFunctionBodyWithComments), [StyleViolation(
-            ruleDescription: FunctionBodyLengthRule.description,
-            location: Location(file: nil, line: 1, character: 6),
-            reason: "Function body should span 50 lines or less excluding comments and " +
-            "whitespace: currently spans 51 lines")])
+        do {
+            let longerFunctionBodyWithComments = violatingFuncWithBody(
+                repeatElement("x = 0\n", count: 51).joined() +
+                "// comment only line should be ignored.\n"
+            )
+            let violations = try await self.violations(longerFunctionBodyWithComments)
+            XCTAssertEqual(violations, [StyleViolation(
+                ruleDescription: FunctionBodyLengthRule.description,
+                location: Location(file: nil, line: 1, character: 6),
+                reason: "Function body should span 50 lines or less excluding comments and " +
+                "whitespace: currently spans 51 lines")])
+        }
     }
 
-    func testFunctionBodyLengthsWithMultilineComments() {
-        let longFunctionBodyWithMultilineComments = funcWithBody(
-            repeatElement("x = 0\n", count: 49).joined() +
-            "/* multi line comment only line should be ignored.\n*/\n"
-        )
-        XCTAssertEqual(self.violations(longFunctionBodyWithMultilineComments), [])
+    func testFunctionBodyLengthsWithMultilineComments() async throws {
+        do {
+            let longFunctionBodyWithMultilineComments = funcWithBody(
+                repeatElement("x = 0\n", count: 49).joined() +
+                "/* multi line comment only line should be ignored.\n*/\n"
+            )
+            let violations = try await self.violations(longFunctionBodyWithMultilineComments)
+            XCTAssertEqual(violations, [])
+        }
 
-        let longerFunctionBodyWithMultilineComments = violatingFuncWithBody(
-            repeatElement("x = 0\n", count: 51).joined() +
-            "/* multi line comment only line should be ignored.\n*/\n"
-        )
-        XCTAssertEqual(self.violations(longerFunctionBodyWithMultilineComments), [StyleViolation(
-            ruleDescription: FunctionBodyLengthRule.description,
-            location: Location(file: nil, line: 1, character: 6),
-            reason: "Function body should span 50 lines or less excluding comments and " +
-            "whitespace: currently spans 51 lines")])
+        do {
+            let longerFunctionBodyWithMultilineComments = violatingFuncWithBody(
+                repeatElement("x = 0\n", count: 51).joined() +
+                "/* multi line comment only line should be ignored.\n*/\n"
+            )
+            let violations = try await self.violations(longerFunctionBodyWithMultilineComments)
+            XCTAssertEqual(violations, [StyleViolation(
+                ruleDescription: FunctionBodyLengthRule.description,
+                location: Location(file: nil, line: 1, character: 6),
+                reason: "Function body should span 50 lines or less excluding comments and " +
+                "whitespace: currently spans 51 lines")])
+        }
     }
 
-    func testConfiguration() {
+    func testConfiguration() async throws {
         let function = violatingFuncWithBody(repeatElement("x = 0\n", count: 10).joined())
 
-        XCTAssertEqual(self.violations(function, configuration: ["warning": 12]).count, 0)
-        XCTAssertEqual(self.violations(function, configuration: ["warning": 12, "error": 14]).count, 0)
-        XCTAssertEqual(
-            self.violations(function, configuration: ["warning": 8]).map(\.reason),
-            ["Function body should span 8 lines or less excluding comments and whitespace: currently spans 10 lines"]
-        )
-        XCTAssertEqual(
-            self.violations(function, configuration: ["warning": 12, "error": 8]).map(\.reason),
-            ["Function body should span 8 lines or less excluding comments and whitespace: currently spans 10 lines"]
-        )
+        do {
+            let violations = try await self.violations(function, configuration: ["warning": 12])
+            XCTAssertEqual(violations, [])
+        }
+
+        do {
+            let violations = try await self.violations(function, configuration: ["warning": 12, "error": 14])
+            XCTAssertEqual(violations, [])
+        }
+
+        do {
+            let violations = try await self.violations(function, configuration: ["warning": 8])
+            XCTAssertEqual(
+                violations.map(\.reason),
+                [
+                    """
+                    Function body should span 8 lines or less excluding comments and whitespace: \
+                    currently spans 10 lines
+                    """
+                ]
+            )
+        }
+        do {
+            let violations = try await self.violations(function, configuration: ["warning": 12, "error": 8])
+            XCTAssertEqual(
+                violations.map(\.reason),
+                [
+                    """
+                    Function body should span 8 lines or less excluding comments and whitespace: \
+                    currently spans 10 lines
+                    """
+                ]
+            )
+        }
     }
 
-    private func violations(_ example: Example, configuration: Any? = nil) -> [StyleViolation] {
+    private func violations(_ example: Example, configuration: Any? = nil) async throws -> [StyleViolation] {
         let config = makeConfig(configuration, FunctionBodyLengthRule.description.identifier)!
-        return SwiftLintFrameworkTests.violations(example, config: config)
+        return try await SwiftLintFrameworkTests.violations(example, config: config)
     }
 }

Tests/SwiftLintFrameworkTests/FunctionParameterCountRuleTests.swift

@@ -11,7 +11,7 @@ private func funcWithParameters(_ parameters: String,
 }
 
 class FunctionParameterCountRuleTests: XCTestCase {
-    func testFunctionParameterCount() {
+    func testFunctionParameterCount() async throws {
         let baseDescription = FunctionParameterCountRule.description
         let nonTriggeringExamples = [
             funcWithParameters(repeatElement("x: Int, ", count: 3).joined() + "x: Int")
@@ -24,10 +24,10 @@ class FunctionParameterCountRuleTests: XCTestCase {
         let description = baseDescription.with(nonTriggeringExamples: nonTriggeringExamples)
             .with(triggeringExamples: triggeringExamples)
 
-        verifyRule(description)
+        try await verifyRule(description)
     }
 
-    func testDefaultFunctionParameterCount() {
+    func testDefaultFunctionParameterCount() async throws {
         let baseDescription = FunctionParameterCountRule.description
         let nonTriggeringExamples = [
             funcWithParameters(repeatElement("x: Int, ", count: 3).joined() + "x: Int")
@@ -41,6 +41,6 @@ class FunctionParameterCountRuleTests: XCTestCase {
         let description = baseDescription.with(nonTriggeringExamples: nonTriggeringExamples)
             .with(triggeringExamples: triggeringExamples)
 
-        verifyRule(description, ruleConfiguration: ["ignores_default_parameters": false])
+        try await verifyRule(description, ruleConfiguration: ["ignores_default_parameters": false])
     }
 }

Tests/SwiftLintFrameworkTests/GenericTypeNameRuleTests.swift

@@ -2,7 +2,7 @@
 import XCTest
 
 class GenericTypeNameRuleTests: XCTestCase {
-    func testGenericTypeNameWithExcluded() {
+    func testGenericTypeNameWithExcluded() async throws {
         let baseDescription = GenericTypeNameRule.description
         let nonTriggeringExamples = baseDescription.nonTriggeringExamples + [
             Example("func foo<apple> {}\n"),
@@ -15,10 +15,10 @@ class GenericTypeNameRuleTests: XCTestCase {
         ]
         let description = baseDescription.with(nonTriggeringExamples: nonTriggeringExamples,
                                                triggeringExamples: triggeringExamples)
-        verifyRule(description, ruleConfiguration: ["excluded": ["apple", "some.*", ".*st\\d+.*"]])
+        try await verifyRule(description, ruleConfiguration: ["excluded": ["apple", "some.*", ".*st\\d+.*"]])
     }
 
-    func testGenericTypeNameWithAllowedSymbols() {
+    func testGenericTypeNameWithAllowedSymbols() async throws {
         let baseDescription = GenericTypeNameRule.description
         let nonTriggeringExamples = baseDescription.nonTriggeringExamples + [
             Example("func foo<T$>() {}\n"),
@@ -30,20 +30,20 @@ class GenericTypeNameRuleTests: XCTestCase {
         ]
 
         let description = baseDescription.with(nonTriggeringExamples: nonTriggeringExamples)
-        verifyRule(description, ruleConfiguration: ["allowed_symbols": ["$", "%"]])
+        try await verifyRule(description, ruleConfiguration: ["allowed_symbols": ["$", "%"]])
     }
 
-    func testGenericTypeNameWithAllowedSymbolsAndViolation() {
+    func testGenericTypeNameWithAllowedSymbolsAndViolation() async throws {
         let baseDescription = GenericTypeNameRule.description
         let triggeringExamples = [
             Example("func foo<↓T_$>() {}\n")
         ]
 
         let description = baseDescription.with(triggeringExamples: triggeringExamples)
-        verifyRule(description, ruleConfiguration: ["allowed_symbols": ["$", "%"]])
+        try await verifyRule(description, ruleConfiguration: ["allowed_symbols": ["$", "%"]])
     }
 
-    func testGenericTypeNameWithIgnoreStartWithLowercase() {
+    func testGenericTypeNameWithIgnoreStartWithLowercase() async throws {
         let baseDescription = GenericTypeNameRule.description
         let triggeringExamplesToRemove = [
             Example("func foo<↓type>() {}\n"),
@@ -58,6 +58,6 @@ class GenericTypeNameRuleTests: XCTestCase {
 
         let description = baseDescription.with(nonTriggeringExamples: nonTriggeringExamples)
                                          .with(triggeringExamples: triggeringExamples)
-        verifyRule(description, ruleConfiguration: ["validates_start_with_lowercase": false])
+        try await verifyRule(description, ruleConfiguration: ["validates_start_with_lowercase": false])
     }
 }

Tests/SwiftLintFrameworkTests/IdentifierNameRuleTests.swift

@@ -2,7 +2,7 @@
 import XCTest
 
 class IdentifierNameRuleTests: XCTestCase {
-    func testIdentifierNameWithExcluded() {
+    func testIdentifierNameWithExcluded() async throws {
         let baseDescription = IdentifierNameRule.description
         let nonTriggeringExamples = baseDescription.nonTriggeringExamples + [
             Example("let Apple = 0"),
@@ -15,10 +15,10 @@ class IdentifierNameRuleTests: XCTestCase {
         ]
         let description = baseDescription.with(nonTriggeringExamples: nonTriggeringExamples,
                                                triggeringExamples: triggeringExamples)
-        verifyRule(description, ruleConfiguration: ["excluded": ["Apple", "some.*", ".*\\d+.*"]])
+        try await verifyRule(description, ruleConfiguration: ["excluded": ["Apple", "some.*", ".*\\d+.*"]])
     }
 
-    func testIdentifierNameWithAllowedSymbols() {
+    func testIdentifierNameWithAllowedSymbols() async throws {
         let baseDescription = IdentifierNameRule.description
         let nonTriggeringExamples = baseDescription.nonTriggeringExamples + [
             Example("let myLet$ = 0"),
@@ -29,20 +29,20 @@ class IdentifierNameRuleTests: XCTestCase {
         let triggeringExamples = baseDescription.triggeringExamples.filter { !$0.code.contains("_") }
         let description = baseDescription.with(nonTriggeringExamples: nonTriggeringExamples,
                                                triggeringExamples: triggeringExamples)
-        verifyRule(description, ruleConfiguration: ["allowed_symbols": ["$", "%", "_"]])
+        try await verifyRule(description, ruleConfiguration: ["allowed_symbols": ["$", "%", "_"]])
     }
 
-    func testIdentifierNameWithAllowedSymbolsAndViolation() {
+    func testIdentifierNameWithAllowedSymbolsAndViolation() async throws {
         let baseDescription = IdentifierNameRule.description
         let triggeringExamples = [
             Example("↓let my_Let$ = 0")
         ]
 
         let description = baseDescription.with(triggeringExamples: triggeringExamples)
-        verifyRule(description, ruleConfiguration: ["allowed_symbols": ["$", "%"]])
+        try await verifyRule(description, ruleConfiguration: ["allowed_symbols": ["$", "%"]])
     }
 
-    func testIdentifierNameWithIgnoreStartWithLowercase() {
+    func testIdentifierNameWithIgnoreStartWithLowercase() async throws {
         let baseDescription = IdentifierNameRule.description
         let triggeringExamplesToRemove = [
             Example("↓let MyLet = 0"),
@@ -57,16 +57,16 @@ class IdentifierNameRuleTests: XCTestCase {
         let description = baseDescription.with(nonTriggeringExamples: nonTriggeringExamples)
                                          .with(triggeringExamples: triggeringExamples)
 
-        verifyRule(description, ruleConfiguration: ["validates_start_with_lowercase": false])
+        try await verifyRule(description, ruleConfiguration: ["validates_start_with_lowercase": false])
     }
 
-    func testLinuxCrashOnEmojiNames() {
+    func testLinuxCrashOnEmojiNames() async throws {
         let baseDescription = IdentifierNameRule.description
         let triggeringExamples = [
             Example("let 👦🏼 = \"👦🏼\"")
         ]
 
         let description = baseDescription.with(triggeringExamples: triggeringExamples)
-        verifyRule(description, ruleConfiguration: ["allowed_symbols": ["$", "%"]])
+        try await verifyRule(description, ruleConfiguration: ["allowed_symbols": ["$", "%"]])
     }
 }

Tests/SwiftLintFrameworkTests/ImplicitGetterRuleTests.swift

@@ -2,7 +2,7 @@
 import XCTest
 
 final class ImplicitGetterRuleTests: XCTestCase {
-    func testPropertyReason() throws {
+    func testPropertyReason() async throws {
         let config = try XCTUnwrap(makeConfig(nil, ImplicitGetterRule.description.identifier))
         let example = Example("""
         class Foo {
@@ -14,12 +14,12 @@ final class ImplicitGetterRuleTests: XCTestCase {
         }
         """)
 
-        let violations = violations(example, config: config)
+        let violations = try await violations(example, config: config)
         XCTAssertEqual(violations.count, 1)
         XCTAssertEqual(violations.first?.reason, "Computed read-only properties should avoid using the get keyword")
     }
 
-    func testSubscriptReason() throws {
+    func testSubscriptReason() async throws {
         let config = try XCTUnwrap(makeConfig(nil, ImplicitGetterRule.description.identifier))
         let example = Example("""
         class Foo {
@@ -31,7 +31,7 @@ final class ImplicitGetterRuleTests: XCTestCase {
         }
         """)
 
-        let violations = violations(example, config: config)
+        let violations = try await violations(example, config: config)
         XCTAssertEqual(violations.count, 1)
         XCTAssertEqual(violations.first?.reason, "Computed read-only subscripts should avoid using the get keyword")
     }

Tests/SwiftLintFrameworkTests/ImplicitReturnRuleTests.swift

@@ -2,7 +2,7 @@
 import XCTest
 
 class ImplicitReturnRuleTests: XCTestCase {
-    func testOnlyClosureKindIncluded() {
+    func testOnlyClosureKindIncluded() async throws {
         let nonTriggeringExamples = ImplicitReturnRuleExamples.GenericExamples.nonTriggeringExamples +
             ImplicitReturnRuleExamples.ClosureExamples.nonTriggeringExamples +
             ImplicitReturnRuleExamples.FunctionExamples.nonTriggeringExamples +
@@ -17,10 +17,10 @@ class ImplicitReturnRuleTests: XCTestCase {
             .with(triggeringExamples: triggeringExamples)
             .with(corrections: corrections)
 
-        self.verifyRule(description, returnKind: .closure)
+        try await self.verifyRule(description, returnKind: .closure)
     }
 
-    func testOnlyFunctionKindIncluded() {
+    func testOnlyFunctionKindIncluded() async throws {
         let nonTriggeringExamples = ImplicitReturnRuleExamples.GenericExamples.nonTriggeringExamples +
             ImplicitReturnRuleExamples.ClosureExamples.nonTriggeringExamples +
             ImplicitReturnRuleExamples.ClosureExamples.triggeringExamples +
@@ -35,10 +35,10 @@ class ImplicitReturnRuleTests: XCTestCase {
             .with(triggeringExamples: triggeringExamples)
             .with(corrections: corrections)
 
-        self.verifyRule(description, returnKind: .function)
+        try await self.verifyRule(description, returnKind: .function)
     }
 
-    func testOnlyGetterKindIncluded() {
+    func testOnlyGetterKindIncluded() async throws {
         let nonTriggeringExamples = ImplicitReturnRuleExamples.GenericExamples.nonTriggeringExamples +
             ImplicitReturnRuleExamples.ClosureExamples.nonTriggeringExamples +
             ImplicitReturnRuleExamples.ClosureExamples.triggeringExamples +
@@ -53,10 +53,11 @@ class ImplicitReturnRuleTests: XCTestCase {
             .with(triggeringExamples: triggeringExamples)
             .with(corrections: corrections)
 
-        self.verifyRule(description, returnKind: .getter)
+        try await self.verifyRule(description, returnKind: .getter)
     }
 
-    private func verifyRule(_ ruleDescription: RuleDescription, returnKind: ImplicitReturnConfiguration.ReturnKind) {
-        self.verifyRule(ruleDescription, ruleConfiguration: ["included": [returnKind.rawValue]])
+    private func verifyRule(_ ruleDescription: RuleDescription, returnKind: ImplicitReturnConfiguration.ReturnKind)
+        async throws {
+        try await self.verifyRule(ruleDescription, ruleConfiguration: ["included": [returnKind.rawValue]])
     }
 }

Tests/SwiftLintFrameworkTests/ImplicitlyUnwrappedOptionalRuleTests.swift

@@ -8,7 +8,7 @@ class ImplicitlyUnwrappedOptionalRuleTests: XCTestCase {
         XCTAssertEqual(rule.configuration.severity, .warning)
     }
 
-    func testImplicitlyUnwrappedOptionalRuleWarnsOnOutletsInAllMode() {
+    func testImplicitlyUnwrappedOptionalRuleWarnsOnOutletsInAllMode() async throws {
         let baseDescription = ImplicitlyUnwrappedOptionalRule.description
         let triggeringExamples = [
             Example("@IBOutlet private var label: UILabel!"),
@@ -20,7 +20,7 @@ class ImplicitlyUnwrappedOptionalRuleTests: XCTestCase {
         let description = baseDescription.with(nonTriggeringExamples: nonTriggeringExamples)
                                          .with(triggeringExamples: triggeringExamples)
 
-        verifyRule(description, ruleConfiguration: ["mode": "all"],
-                   commentDoesntViolate: true, stringDoesntViolate: true)
+        try await verifyRule(description, ruleConfiguration: ["mode": "all"],
+                             commentDoesntViolate: true, stringDoesntViolate: true)
     }
 }

Tests/SwiftLintFrameworkTests/InclusiveLanguageRuleTests.swift

@@ -2,21 +2,21 @@
 import XCTest
 
 class InclusiveLanguageRuleTests: XCTestCase {
-    func testNonTriggeringExamplesWithNonDefaultConfig() {
-        InclusiveLanguageRuleExamples.nonTriggeringExamplesWithConfig.forEach { example in
+    func testNonTriggeringExamplesWithNonDefaultConfig() async throws {
+        for example in InclusiveLanguageRuleExamples.nonTriggeringExamplesWithConfig {
             let description = InclusiveLanguageRule.description
                 .with(nonTriggeringExamples: [example])
                 .with(triggeringExamples: [])
-            verifyRule(description, ruleConfiguration: example.configuration)
+            try await verifyRule(description, ruleConfiguration: example.configuration)
         }
     }
 
-    func testTriggeringExamplesWithNonDefaultConfig() {
-        InclusiveLanguageRuleExamples.triggeringExamplesWithConfig.forEach { example in
+    func testTriggeringExamplesWithNonDefaultConfig() async throws {
+        for example in InclusiveLanguageRuleExamples.triggeringExamplesWithConfig {
             let description = InclusiveLanguageRule.description
                 .with(nonTriggeringExamples: [])
                 .with(triggeringExamples: [example])
-            verifyRule(description, ruleConfiguration: example.configuration)
+            try await verifyRule(description, ruleConfiguration: example.configuration)
         }
     }
 }

Tests/SwiftLintFrameworkTests/IndentationWidthRuleTests.swift

@@ -4,166 +4,168 @@ import XCTest
 class IndentationWidthRuleTests: XCTestCase {
     // MARK: Examples
     /// It's not okay to have the first line indented.
-    func testFirstLineIndentation() {
-        assert1Violation(in: "    firstLine")
-        assert1Violation(in: "   firstLine")
-        assert1Violation(in: " firstLine")
-        assert1Violation(in: "\tfirstLine")
+    func testFirstLineIndentation() async throws {
+        try await assert1Violation(in: "    firstLine")
+        try await assert1Violation(in: "   firstLine")
+        try await assert1Violation(in: " firstLine")
+        try await assert1Violation(in: "\tfirstLine")
 
-        assertNoViolation(in: "firstLine")
+        try await assertNoViolation(in: "firstLine")
     }
 
     /// It's not okay to indent using both tabs and spaces in one line.
-    func testMixedTabSpaceIndentation() {
+    func testMixedTabSpaceIndentation() async throws {
         // Expect 2 violations as secondLine is also indented by 8 spaces (which isn't valid)
-        assertViolations(in: "firstLine\n\t    secondLine", equals: 2)
-        assertViolations(in: "firstLine\n    \tsecondLine", equals: 2)
+        try await assertViolations(in: "firstLine\n\t    secondLine", equals: 2)
+        try await assertViolations(in: "firstLine\n    \tsecondLine", equals: 2)
     }
 
     /// It's okay to indent using either tabs or spaces in different lines.
-    func testMixedTabsAndSpacesIndentation() {
-        assertNoViolation(in: "firstLine\n\tsecondLine\n        thirdLine")
-        assertNoViolation(in: "firstLine\n    secondLine\n\t\tthirdLine")
-        assertNoViolation(in: "firstLine\n\tsecondLine\n        thirdLine\n\t\t\tfourthLine")
+    func testMixedTabsAndSpacesIndentation() async throws {
+        try await assertNoViolation(in: "firstLine\n\tsecondLine\n        thirdLine")
+        try await assertNoViolation(in: "firstLine\n    secondLine\n\t\tthirdLine")
+        try await assertNoViolation(in: "firstLine\n\tsecondLine\n        thirdLine\n\t\t\tfourthLine")
     }
 
     /// It's okay to keep the same indentation.
-    func testKeepingIndentation() {
-        assertNoViolation(in: "firstLine\nsecondLine")
-        assertNoViolation(in: "firstLine    \nsecondLine\n    thirdLine")
-        assertNoViolation(in: "firstLine\t\nsecondLine\n\tthirdLine")
+    func testKeepingIndentation() async throws {
+        try await assertNoViolation(in: "firstLine\nsecondLine")
+        try await assertNoViolation(in: "firstLine    \nsecondLine\n    thirdLine")
+        try await assertNoViolation(in: "firstLine\t\nsecondLine\n\tthirdLine")
     }
 
     /// It's only okay to indent using one tab or indentationWidth spaces.
-    func testIndentationLength() {
-        assert1Violation(in: "firstLine\n        secondLine", indentationWidth: 1)
-        assert1Violation(in: "firstLine\n        secondLine", indentationWidth: 2)
-        assert1Violation(in: "firstLine\n        secondLine", indentationWidth: 3)
-        assert1Violation(in: "firstLine\n        secondLine", indentationWidth: 4)
-        assert1Violation(in: "firstLine\n        secondLine", indentationWidth: 5)
-        assert1Violation(in: "firstLine\n        secondLine", indentationWidth: 6)
-        assert1Violation(in: "firstLine\n        secondLine", indentationWidth: 7)
-        assert1Violation(in: "firstLine\n\t\tsecondLine")
-        assert1Violation(in: "firstLine\n\t\t\tsecondLine")
-        assert1Violation(in: "firstLine\n\t\t\t\t\t\tsecondLine")
+    func testIndentationLength() async throws {
+        try await assert1Violation(in: "firstLine\n        secondLine", indentationWidth: 1)
+        try await assert1Violation(in: "firstLine\n        secondLine", indentationWidth: 2)
+        try await assert1Violation(in: "firstLine\n        secondLine", indentationWidth: 3)
+        try await assert1Violation(in: "firstLine\n        secondLine", indentationWidth: 4)
+        try await assert1Violation(in: "firstLine\n        secondLine", indentationWidth: 5)
+        try await assert1Violation(in: "firstLine\n        secondLine", indentationWidth: 6)
+        try await assert1Violation(in: "firstLine\n        secondLine", indentationWidth: 7)
+        try await assert1Violation(in: "firstLine\n\t\tsecondLine")
+        try await assert1Violation(in: "firstLine\n\t\t\tsecondLine")
+        try await assert1Violation(in: "firstLine\n\t\t\t\t\t\tsecondLine")
 
-        assertNoViolation(in: "firstLine\n\tsecondLine")
-        assertNoViolation(in: "firstLine\n secondLine", indentationWidth: 1)
-        assertNoViolation(in: "firstLine\n  secondLine", indentationWidth: 2)
-        assertNoViolation(in: "firstLine\n   secondLine", indentationWidth: 3)
-        assertNoViolation(in: "firstLine\n    secondLine", indentationWidth: 4)
-        assertNoViolation(in: "firstLine\n     secondLine", indentationWidth: 5)
-        assertNoViolation(in: "firstLine\n      secondLine", indentationWidth: 6)
-        assertNoViolation(in: "firstLine\n       secondLine", indentationWidth: 7)
-        assertNoViolation(in: "firstLine\n        secondLine", indentationWidth: 8)
+        try await assertNoViolation(in: "firstLine\n\tsecondLine")
+        try await assertNoViolation(in: "firstLine\n secondLine", indentationWidth: 1)
+        try await assertNoViolation(in: "firstLine\n  secondLine", indentationWidth: 2)
+        try await assertNoViolation(in: "firstLine\n   secondLine", indentationWidth: 3)
+        try await assertNoViolation(in: "firstLine\n    secondLine", indentationWidth: 4)
+        try await assertNoViolation(in: "firstLine\n     secondLine", indentationWidth: 5)
+        try await assertNoViolation(in: "firstLine\n      secondLine", indentationWidth: 6)
+        try await assertNoViolation(in: "firstLine\n       secondLine", indentationWidth: 7)
+        try await assertNoViolation(in: "firstLine\n        secondLine", indentationWidth: 8)
     }
 
     /// It's okay to unindent indentationWidth * (1, 2, 3, ...) - x iff x == 0.
-    func testUnindentation() {
-        assert1Violation(in: "firstLine\n    secondLine\n        thirdLine\n fourthLine")
-        assert1Violation(in: "firstLine\n    secondLine\n        thirdLine\n  fourthLine")
-        assert1Violation(in: "firstLine\n    secondLine\n        thirdLine\n   fourthLine")
-        assert1Violation(in: "firstLine\n    secondLine\n    thirdLine\n   fourthLine")
+    func testUnindentation() async throws {
+        try await assert1Violation(in: "firstLine\n    secondLine\n        thirdLine\n fourthLine")
+        try await assert1Violation(in: "firstLine\n    secondLine\n        thirdLine\n  fourthLine")
+        try await assert1Violation(in: "firstLine\n    secondLine\n        thirdLine\n   fourthLine")
+        try await assert1Violation(in: "firstLine\n    secondLine\n    thirdLine\n   fourthLine")
 
-        assertNoViolation(in: "firstLine\n    secondLine\n        thirdLine\nfourthLine")
-        assertNoViolation(in: "firstLine\n    secondLine\n    thirdLine\nfourthLine")
-        assertNoViolation(in: "firstLine\n\tsecondLine\n\t\tthirdLine\n\t\t\tfourthLine\nfifthLine")
+        try await assertNoViolation(in: "firstLine\n    secondLine\n        thirdLine\nfourthLine")
+        try await assertNoViolation(in: "firstLine\n    secondLine\n    thirdLine\nfourthLine")
+        try await assertNoViolation(in: "firstLine\n\tsecondLine\n\t\tthirdLine\n\t\t\tfourthLine\nfifthLine")
     }
 
     /// It's okay to have empty lines between iff the following indentations obey the rules.
-    func testEmptyLinesBetween() {
-        assertNoViolation(in: "firstLine\n\tsecondLine\n\n\tfourthLine")
-        assertNoViolation(in: "firstLine\n\tsecondLine\n \n\tfourthLine")
-        assertNoViolation(in: "firstLine\n\tsecondLine\n           \n\tfourthLine")
-        assertNoViolation(in: "firstLine\n\tsecondLine\n\n    fourthLine")
-        assertNoViolation(in: "firstLine\n\tsecondLine\n \n    fourthLine")
-        assertNoViolation(in: "firstLine\n\tsecondLine\n           \n    fourthLine")
+    func testEmptyLinesBetween() async throws {
+        try await assertNoViolation(in: "firstLine\n\tsecondLine\n\n\tfourthLine")
+        try await assertNoViolation(in: "firstLine\n\tsecondLine\n \n\tfourthLine")
+        try await assertNoViolation(in: "firstLine\n\tsecondLine\n           \n\tfourthLine")
+        try await assertNoViolation(in: "firstLine\n\tsecondLine\n\n    fourthLine")
+        try await assertNoViolation(in: "firstLine\n\tsecondLine\n \n    fourthLine")
+        try await assertNoViolation(in: "firstLine\n\tsecondLine\n           \n    fourthLine")
 
-        assert1Violation(in: "firstLine\n\tsecondLine\n\n\t\t\tfourthLine")
-        assert1Violation(in: "firstLine\n\tsecondLine\n \n\t\t\tfourthLine")
-        assert1Violation(in: "firstLine\n\tsecondLine\n           \n\t\t\tfourthLine")
-        assert1Violation(in: "firstLine\n\tsecondLine\n\n            fourthLine")
-        assert1Violation(in: "firstLine\n\tsecondLine\n \n            fourthLine")
-        assert1Violation(in: "firstLine\n\tsecondLine\n           \n            fourthLine")
+        try await assert1Violation(in: "firstLine\n\tsecondLine\n\n\t\t\tfourthLine")
+        try await assert1Violation(in: "firstLine\n\tsecondLine\n \n\t\t\tfourthLine")
+        try await assert1Violation(in: "firstLine\n\tsecondLine\n           \n\t\t\tfourthLine")
+        try await assert1Violation(in: "firstLine\n\tsecondLine\n\n            fourthLine")
+        try await assert1Violation(in: "firstLine\n\tsecondLine\n \n            fourthLine")
+        try await assert1Violation(in: "firstLine\n\tsecondLine\n           \n            fourthLine")
     }
 
-    func testsBrackets() {
-        assertNoViolation(
+    func testsBrackets() async throws {
+        try await assertNoViolation(
             in: "firstLine\n    [\n        .thirdLine\n    ]\nfifthLine",
             includeComments: true
         )
 
-        assertNoViolation(
+        try await assertNoViolation(
             in: "firstLine\n    [\n        .thirdLine\n    ]\nfifthLine",
             includeComments: false
         )
 
-        assertNoViolation(
+        try await assertNoViolation(
             in: "firstLine\n    (\n        .thirdLine\n    )\nfifthLine",
             includeComments: true
         )
 
-        assertNoViolation(
+        try await assertNoViolation(
             in: "firstLine\n    (\n        .thirdLine\n    )\nfifthLine",
             includeComments: false
         )
     }
 
     /// It's okay to have comments not following the indentation pattern iff the configuration allows this.
-    func testCommentLines() {
-        assert1Violation(
+    func testCommentLines() async throws {
+        try await assert1Violation(
             in: "firstLine\n\tsecondLine\n\t\tthirdLine\n//test\n\t\tfourthLine",
             includeComments: true
         )
-        assertViolations(
+        try await assertViolations(
             in: "firstLine\n\tsecondLine\n\t\tthirdLine\n//test\n // test\n//test\n\t\tfourthLine",
             equals: 2,
             includeComments: true
         )
-        assertViolations(
+        try await assertViolations(
             in: "firstLine\n\tsecondLine\n\t\tthirdLine\n/*test\n  bad indent...\n test*/\n\t\tfourthLine",
             equals: 3,
             includeComments: true
         )
 
-        assertNoViolation(
+        try await assertNoViolation(
             in: "firstLine\n\tsecondLine\n\t\tthirdLine\n//test\n\t\tfourthLine",
             includeComments: false
         )
-        assertNoViolation(
+        try await assertNoViolation(
             in: "firstLine\n\tsecondLine\n\t\tthirdLine\n//test\n // test\n//test\n\t\tfourthLine",
             includeComments: false
         )
-        assertNoViolation(
+        try await assertNoViolation(
             in: "firstLine\n\tsecondLine\n\t\tthirdLine\n/*test\n  bad indent...\n test*/\n\t\tfourthLine",
             includeComments: false
         )
     }
 
     /// Duplicate warnings for one actual indentation issue should be avoided.
-    func testDuplicateWarningAvoidanceMechanism() {
+    func testDuplicateWarningAvoidanceMechanism() async throws {
         // thirdLine is indented correctly, yet not in-line with the badly indented secondLine. This should be allowed.
-        assert1Violation(in: "firstLine\n secondLine\nthirdLine")
+        try await assert1Violation(in: "firstLine\n secondLine\nthirdLine")
 
         // thirdLine is indented correctly, yet not in-line with the badly indented secondLine. This should be allowed.
-        assert1Violation(in: "firstLine\n     secondLine\n    thirdLine")
+        try await assert1Violation(in: "firstLine\n     secondLine\n    thirdLine")
 
         // thirdLine is indented badly, yet in-line with the badly indented secondLine. This should be allowed.
-        assert1Violation(in: "firstLine\n     secondLine\n     thirdLine")
+        try await assert1Violation(in: "firstLine\n     secondLine\n     thirdLine")
 
         // This pattern should go on indefinitely...
-        assert1Violation(in: "firstLine\n     secondLine\n     thirdLine\n    fourthLine")
-        assert1Violation(in: "firstLine\n     secondLine\n     thirdLine\n     fourthLine")
+        try await assert1Violation(in: "firstLine\n     secondLine\n     thirdLine\n    fourthLine")
+        try await assert1Violation(in: "firstLine\n     secondLine\n     thirdLine\n     fourthLine")
 
         // Still, this won't disable multiple line warnings in one file if suitable...
-        assertViolations(in: "firstLine\n     secondLine\nthirdLine\n     fourthLine", equals: 2)
-        assertViolations(in: "firstLine\n     secondLine\n    thirdLine\n     fourthLine", equals: 2)
-        assertViolations(in: "firstLine\n     secondLine\n     thirdLine\nfourthLine\n     fifthLine", equals: 2)
-        assertViolations(in: "firstLine\n     secondLine\n     thirdLine\n    fourthLine\n     fifthLine", equals: 2)
+        try await assertViolations(in: "firstLine\n     secondLine\nthirdLine\n     fourthLine", equals: 2)
+        try await assertViolations(in: "firstLine\n     secondLine\n    thirdLine\n     fourthLine", equals: 2)
+        try await assertViolations(in: "firstLine\n     secondLine\n     thirdLine\nfourthLine\n     fifthLine",
+                                   equals: 2)
+        try await assertViolations(in: "firstLine\n     secondLine\n     thirdLine\n    fourthLine\n     fifthLine",
+                                   equals: 2)
     }
 
-    func testIgnoredCompilerDirectives() {
-        assertNoViolation(in: """
+    func testIgnoredCompilerDirectives() async throws {
+        try await assertNoViolation(in: """
             struct S {
                             #if os(iOS)
                 var i: Int = 0
@@ -179,7 +181,7 @@ class IndentationWidthRuleTests: XCTestCase {
             }
             """, includeCompilerDirectives: false)
 
-        assertNoViolation(in: """
+        try await assertNoViolation(in: """
             struct S {
                 #if os(iOS)
                     var i: Int = 0
@@ -204,7 +206,7 @@ class IndentationWidthRuleTests: XCTestCase {
         includeCompilerDirectives: Bool? = nil,
         file: StaticString = #file,
         line: UInt = #line
-    ) -> Int {
+    ) async throws -> Int {
         var configDict: [String: Any] = [:]
         if let indentationWidth {
             configDict["indentation_width"] = indentationWidth
@@ -221,7 +223,7 @@ class IndentationWidthRuleTests: XCTestCase {
             return 0
         }
 
-        return violations(example.with(code: example.code + "\n"), config: config).count
+        return try await violations(example.with(code: example.code + "\n"), config: config).count
     }
 
     private func assertViolations(
@@ -232,20 +234,16 @@ class IndentationWidthRuleTests: XCTestCase {
         includeCompilerDirectives: Bool? = nil,
         file: StaticString = #file,
         line: UInt = #line
-    ) {
-        XCTAssertEqual(
-            countViolations(
-                in: Example(string, file: (file), line: line),
-                indentationWidth: indentationWidth,
-                includeComments: includeComments,
-                includeCompilerDirectives: includeCompilerDirectives,
-                file: file,
-                line: line
-            ),
-            expectedCount,
-            file: (file),
+    ) async throws {
+        let actualCount = try await countViolations(
+            in: Example(string, file: (file), line: line),
+            indentationWidth: indentationWidth,
+            includeComments: includeComments,
+            includeCompilerDirectives: includeCompilerDirectives,
+            file: file,
             line: line
         )
+        XCTAssertEqual(actualCount, expectedCount, file: file, line: line)
     }
 
     private func assertNoViolation(
@@ -255,8 +253,8 @@ class IndentationWidthRuleTests: XCTestCase {
         includeCompilerDirectives: Bool? = nil,
         file: StaticString = #file,
         line: UInt = #line
-    ) {
-        assertViolations(
+    ) async throws {
+        try await assertViolations(
             in: string,
             equals: 0,
             indentationWidth: indentationWidth,
@@ -274,8 +272,8 @@ class IndentationWidthRuleTests: XCTestCase {
         includeCompilerDirectives: Bool? = nil,
         file: StaticString = #file,
         line: UInt = #line
-    ) {
-        assertViolations(
+    ) async throws {
+        try await assertViolations(
             in: string,
             equals: 1,
             indentationWidth: indentationWidth,

Tests/SwiftLintFrameworkTests/LineEndingTests.swift

@@ -2,11 +2,8 @@
 import XCTest
 
 class LineEndingTests: XCTestCase {
-    func testCarriageReturnDoesNotCauseError() {
-        XCTAssert(
-            violations(
-                Example("// swiftlint:disable all\r\nprint(123)\r\n")
-            ).isEmpty
-        )
+    func testCarriageReturnDoesNotCauseError() async throws {
+        let violations = try await violations(Example("// swiftlint:disable all\r\nprint(123)\r\n"))
+        XCTAssertEqual(violations, [])
     }
 }