Fix changelog formatting

CHANGELOG.md

@@ -15,6 +15,19 @@
   [Ornithologist Coder](https://github.com/ornithocoder)
   [#52](https://github.com/realm/SwiftLint/issues/52)
 
+* [Experimental] Add a new `CompilerArgumentRule` type which can lint Swift
+  files using the full type-checked AST. Rules of this type will be added over
+  time. The compiler log path containing the clean `swiftc` build command
+  invocation (incremental builds will fail) must be passed to `lint` or
+  `autocorrect` via the `--compiler-log-path` flag.
+  e.g. `--compiler-log-path /path/to/xcodebuild.log`  
+  [JP Simard](https://github.com/jpsim)
+
+* [Experimental] Add a new opt-in `explicit_self` rule to enforce the use of
+  explicit references to `self.` when accessing instance variables or
+  functions.  
+  [JP Simard](https://github.com/jpsim)
+
 #### Bug Fixes
 
 * Fix `comma` rule false positives on object literals (for example, images).  

Rules.md

@@ -35,6 +35,7 @@
 * [Explicit ACL](#explicit-acl)
 * [Explicit Enum Raw Value](#explicit-enum-raw-value)
 * [Explicit Init](#explicit-init)
+* [Explicit Self](#explicit-self)
 * [Explicit Top Level ACL](#explicit-top-level-acl)
 * [Explicit Type Interface](#explicit-type-interface)
 * [Extension Access Modifier](#extension-access-modifier)
@@ -5341,6 +5342,63 @@ func foo() -> [String] {
 
 
 
+## Explicit Self
+
+Identifier | Enabled by default | Supports autocorrection | Kind | Minimum Swift Compiler Version
+--- | --- | --- | --- | ---
+`explicit_self` | Disabled | Yes | style | 3.0.0 
+
+Instance variables and functions should be explicitly accessed with 'self.'.
+
+### Examples
+
+<details>
+<summary>Non Triggering Examples</summary>
+
+```swift
+struct A {
+    func f1() {}
+    func f2() {
+        self.f1()
+    }
+}
+```
+
+```swift
+struct A {
+    let p1: Int
+    func f1() {
+        _ = self.p1
+    }
+}
+```
+
+</details>
+<details>
+<summary>Triggering Examples</summary>
+
+```swift
+struct A {
+    func f1() {}
+    func f2() {
+        ↓f1()
+    }
+}
+```
+
+```swift
+struct A {
+    let p1: Int
+    func f1() {
+        _ = ↓p1
+    }
+}
+```
+
+</details>
+
+
+
 ## Explicit Top Level ACL
 
 Identifier | Enabled by default | Supports autocorrection | Kind | Minimum Swift Compiler Version

Source/SwiftLintFramework/Models/Linter.swift

@@ -46,7 +46,8 @@ private extension Rule {
     }
 
     func lint(file: File, regions: [Region], benchmark: Bool,
-              superfluousDisableCommandRule: SuperfluousDisableCommandRule?) -> LintResult? {
+              superfluousDisableCommandRule: SuperfluousDisableCommandRule?,
+              compilerArguments: [String]) -> LintResult? {
         if !(self is SourceKitFreeRule) && file.sourcekitdFailed {
             return nil
         }
@@ -57,10 +58,10 @@ private extension Rule {
         let ruleTime: (String, Double)?
         if benchmark {
             let start = Date()
-            violations = validate(file: file)
+            violations = validate(file: file, compilerArguments: compilerArguments)
             ruleTime = (ruleID, -start.timeIntervalSinceNow)
         } else {
-            violations = validate(file: file)
+            violations = validate(file: file, compilerArguments: compilerArguments)
             ruleTime = nil
         }
 
@@ -104,6 +105,7 @@ public struct Linter {
     private let rules: [Rule]
     private let cache: LinterCache?
     private let configuration: Configuration
+    private let compilerArguments: [String]
 
     public var styleViolations: [StyleViolation] {
         return getStyleViolations().0
@@ -128,7 +130,8 @@ public struct Linter {
         }) as? SuperfluousDisableCommandRule
         let validationResults = rules.parallelFlatMap {
             $0.lint(file: self.file, regions: regions, benchmark: benchmark,
-                    superfluousDisableCommandRule: superfluousDisableCommandRule)
+                    superfluousDisableCommandRule: superfluousDisableCommandRule,
+                    compilerArguments: self.compilerArguments)
         }
         let violations = validationResults.flatMap { $0.violations }
         let ruleTimes = validationResults.compactMap { $0.ruleTime }
@@ -170,11 +173,13 @@ public struct Linter {
         return (cachedViolations, ruleTimes)
     }
 
-    public init(file: File, configuration: Configuration = Configuration()!, cache: LinterCache? = nil) {
+    public init(file: File, configuration: Configuration = Configuration()!, cache: LinterCache? = nil,
+                compilerArguments: [String] = []) {
         self.file = file
-        self.cache = cache
         self.configuration = configuration
-        rules = configuration.rules
+        self.cache = cache
+        self.compilerArguments = compilerArguments
+        self.rules = configuration.rules
     }
 
     public func correct() -> [Correction] {
@@ -184,7 +189,7 @@ public struct Linter {
 
         var corrections = [Correction]()
         for rule in rules.compactMap({ $0 as? CorrectableRule }) {
-            let newCorrections = rule.correct(file: file)
+            let newCorrections = rule.correct(file: file, compilerArguments: compilerArguments)
             corrections += newCorrections
             if !newCorrections.isEmpty {
                 file.invalidateCache()

Source/SwiftLintFramework/Models/MasterRuleList.swift

@@ -36,6 +36,7 @@ public let masterRuleList = RuleList(rules: [
     ExplicitACLRule.self,
     ExplicitEnumRawValueRule.self,
     ExplicitInitRule.self,
+    ExplicitSelfRule.self,
     ExplicitTopLevelACLRule.self,
     ExplicitTypeInterfaceRule.self,
     ExtensionAccessModifierRule.self,

Source/SwiftLintFramework/Models/RuleDescription.swift

@@ -8,6 +8,7 @@ public struct RuleDescription: Equatable {
     public let corrections: [String: String]
     public let deprecatedAliases: Set<String>
     public let minSwiftVersion: SwiftVersion
+    public let requiresFileOnDisk: Bool
 
     public var consoleDescription: String { return "\(name) (\(identifier)): \(description)" }
 
@@ -19,7 +20,8 @@ public struct RuleDescription: Equatable {
                 minSwiftVersion: SwiftVersion = .three,
                 nonTriggeringExamples: [String] = [], triggeringExamples: [String] = [],
                 corrections: [String: String] = [:],
-                deprecatedAliases: Set<String> = []) {
+                deprecatedAliases: Set<String> = [],
+                requiresFileOnDisk: Bool = false) {
         self.identifier = identifier
         self.name = name
         self.description = description
@@ -29,6 +31,7 @@ public struct RuleDescription: Equatable {
         self.corrections = corrections
         self.deprecatedAliases = deprecatedAliases
         self.minSwiftVersion = minSwiftVersion
+        self.requiresFileOnDisk = requiresFileOnDisk
     }
 }
 

Source/SwiftLintFramework/Protocols/Rule.swift

@@ -7,11 +7,16 @@ public protocol Rule {
     init() // Rules need to be able to be initialized with default values
     init(configuration: Any) throws
 
+    func validate(file: File, compilerArguments: [String]) -> [StyleViolation]
     func validate(file: File) -> [StyleViolation]
     func isEqualTo(_ rule: Rule) -> Bool
 }
 
 extension Rule {
+    public func validate(file: File, compilerArguments: [String]) -> [StyleViolation] {
+        return validate(file: file)
+    }
+
     public func isEqualTo(_ rule: Rule) -> Bool {
         return type(of: self).description == type(of: rule).description
     }
@@ -32,11 +37,32 @@ public protocol ConfigurationProviderRule: Rule {
 }
 
 public protocol CorrectableRule: Rule {
+    func correct(file: File, compilerArguments: [String]) -> [Correction]
     func correct(file: File) -> [Correction]
 }
 
+public extension CorrectableRule {
+    func correct(file: File, compilerArguments: [String]) -> [Correction] {
+        return correct(file: file)
+    }
+}
+
 public protocol SourceKitFreeRule: Rule {}
 
+public protocol CompilerArgumentRule: Rule {}
+
+public extension CompilerArgumentRule {
+    func validate(file: File) -> [StyleViolation] {
+        return validate(file: file, compilerArguments: [])
+    }
+}
+
+public extension CompilerArgumentRule where Self: CorrectableRule {
+    func correct(file: File) -> [Correction] {
+        return correct(file: file, compilerArguments: [])
+    }
+}
+
 // MARK: - ConfigurationProviderRule conformance to Configurable
 
 public extension ConfigurationProviderRule {

Source/SwiftLintFramework/Rules/Style/ExplicitSelfRule.swift

@@ -0,0 +1,199 @@
+import Foundation
+import SourceKittenFramework
+
+public struct ExplicitSelfRule: CorrectableRule, ConfigurationProviderRule, CompilerArgumentRule, OptInRule,
+    AutomaticTestableRule {
+    public var configuration = SeverityConfiguration(.warning)
+
+    public init() {}
+
+    public static let description = RuleDescription(
+        identifier: "explicit_self",
+        name: "Explicit Self",
+        description: "Instance variables and functions should be explicitly accessed with 'self.'.",
+        kind: .style,
+        nonTriggeringExamples: [
+            """
+            struct A {
+                func f1() {}
+                func f2() {
+                    self.f1()
+                }
+            }
+            """,
+            """
+            struct A {
+                let p1: Int
+                func f1() {
+                    _ = self.p1
+                }
+            }
+            """
+        ],
+        triggeringExamples: [
+            """
+            struct A {
+                func f1() {}
+                func f2() {
+                    ↓f1()
+                }
+            }
+            """,
+            """
+            struct A {
+                let p1: Int
+                func f1() {
+                    _ = ↓p1
+                }
+            }
+            """
+        ],
+        corrections: [
+            """
+            struct A {
+                func f1() {}
+                func f2() {
+                    ↓f1()
+                }
+            }
+            """:
+            """
+            struct A {
+                func f1() {}
+                func f2() {
+                    self.f1()
+                }
+            }
+            """,
+            """
+            struct A {
+                let p1: Int
+                func f1() {
+                    _ = ↓p1
+                }
+            }
+            """:
+            """
+            struct A {
+                let p1: Int
+                func f1() {
+                    _ = self.p1
+                }
+            }
+            """
+        ],
+        requiresFileOnDisk: true
+    )
+
+    public func validate(file: File, compilerArguments: [String]) -> [StyleViolation] {
+        return violationRanges(in: file, compilerArguments: compilerArguments).map {
+            StyleViolation(ruleDescription: type(of: self).description,
+                           severity: configuration.severity,
+                           location: Location(file: file, characterOffset: $0.location))
+        }
+    }
+
+    public func correct(file: File, compilerArguments: [String]) -> [Correction] {
+        let violations = violationRanges(in: file, compilerArguments: compilerArguments)
+        let matches = file.ruleEnabled(violatingRanges: violations, for: self)
+        if matches.isEmpty { return [] }
+
+        var contents = file.contents.bridge()
+        let description = type(of: self).description
+        var corrections = [Correction]()
+        for range in matches.reversed() {
+            contents = contents.replacingCharacters(in: range, with: "self.").bridge()
+            let location = Location(file: file, characterOffset: range.location)
+            corrections.append(Correction(ruleDescription: description, location: location))
+        }
+        file.write(contents.bridge())
+        return corrections
+    }
+
+    private func violationRanges(in file: File, compilerArguments: [String]) -> [NSRange] {
+        guard !compilerArguments.isEmpty else {
+            return []
+        }
+
+        let allCursorInfo: [[String: SourceKitRepresentable]]
+        do {
+            let byteOffsets = try binaryOffsets(file: file, compilerArguments: compilerArguments)
+            allCursorInfo = try file.allCursorInfo(compilerArguments: compilerArguments,
+                                                   atByteOffsets: byteOffsets)
+        } catch {
+            queuedPrintError(String(describing: error))
+            return []
+        }
+
+        let cursorsMissingExplicitSelf = allCursorInfo.filter { cursorInfo in
+            guard let kindString = cursorInfo["key.kind"] as? String else { return false }
+            return kindsToFind.contains(kindString)
+        }
+
+        guard !cursorsMissingExplicitSelf.isEmpty else {
+            return []
+        }
+
+        let contents = file.contents.bridge()
+
+        return cursorsMissingExplicitSelf.compactMap { cursorInfo in
+            guard let byteOffset = cursorInfo["swiftlint.offset"] as? Int64 else {
+                queuedPrintError("couldn't convert offsets")
+                return nil
+            }
+
+            return contents.byteRangeToNSRange(start: Int(byteOffset), length: 0)
+        }
+    }
+}
+
+private let kindsToFind = Set([
+    "source.lang.swift.ref.function.method.instance",
+    "source.lang.swift.ref.var.instance"
+])
+
+private extension File {
+    func allCursorInfo(compilerArguments: [String], atByteOffsets byteOffsets: [Int]) throws
+        -> [[String: SourceKitRepresentable]] {
+        return try byteOffsets.compactMap { offset in
+            if contents.bridge().substringWithByteRange(start: offset - 1, length: 1)! == "." { return nil }
+            var cursorInfo = try Request.cursorInfo(file: self.path!, offset: Int64(offset),
+                                                    arguments: compilerArguments).send()
+            cursorInfo["swiftlint.offset"] = Int64(offset)
+            return cursorInfo
+        }
+    }
+}
+
+private extension NSString {
+    func byteOffset(forLine line: Int, column: Int) -> Int {
+        var byteOffset = 0
+        for line in lines()[..<(line - 1)] {
+            byteOffset += line.byteRange.length
+        }
+        return byteOffset + column - 1
+    }
+
+    func recursiveByteOffsets(_ dict: [String: Any]) -> [Int] {
+        let cur: [Int]
+        if let line = dict["key.line"] as? Int64,
+            let column = dict["key.column"] as? Int64,
+            let kindString = dict["key.kind"] as? String,
+            kindsToFind.contains(kindString) {
+            cur = [byteOffset(forLine: Int(line), column: Int(column))]
+        } else {
+            cur = []
+        }
+        if let entities = dict["key.entities"] as? [[String: Any]] {
+            return entities.flatMap(recursiveByteOffsets) + cur
+        }
+        return cur
+    }
+}
+
+private func binaryOffsets(file: File, compilerArguments: [String]) throws -> [Int] {
+    let absoluteFile = file.path!.bridge().absolutePathRepresentation()
+    let index = try Request.index(file: absoluteFile, arguments: compilerArguments).send()
+    let binaryOffsets = file.contents.bridge().recursiveByteOffsets(index)
+    return binaryOffsets.sorted()
+}

Source/swiftlint/Commands/AutoCorrectCommand.swift

@@ -7,47 +7,19 @@ struct AutoCorrectCommand: CommandProtocol {
     let function = "Automatically correct warnings and errors"
 
     func run(_ options: AutoCorrectOptions) -> Result<(), CommandantError<()>> {
-        let configuration = Configuration(options: options)
-        let cache = options.ignoreCache ? nil : LinterCache(configuration: configuration)
-        let indentWidth: Int
-        var useTabs: Bool
-
-        switch configuration.indentation {
-        case .tabs:
-            indentWidth = 4
-            useTabs = true
-        case .spaces(let count):
-            indentWidth = count
-            useTabs = false
-        }
-
-        if options.useTabs {
-            queuedPrintError("'use-tabs' is deprecated and will be completely removed" +
-                " in a future release. 'indentation' can now be defined in a configuration file.")
-            useTabs = options.useTabs
-        }
-
-        return configuration.visitLintableFiles(paths: options.paths, action: "Correcting",
-                                                quiet: options.quiet,
-                                                useScriptInputFiles: options.useScriptInputFiles,
-                                                forceExclude: options.forceExclude,
-                                                cache: cache, parallel: true) { linter in
-            let corrections = linter.correct()
-            if !corrections.isEmpty && !options.quiet {
-                let correctionLogs = corrections.map({ $0.consoleDescription })
-                queuedPrint(correctionLogs.joined(separator: "\n"))
-            }
-            if options.format {
-                linter.format(useTabs: useTabs, indentWidth: indentWidth)
-            }
-        }.flatMap { files in
-            if !options.quiet {
-                let pluralSuffix = { (collection: [Any]) -> String in
-                    return collection.count != 1 ? "s" : ""
+        switch options.visitor {
+        case let .success(visitor):
+            return Configuration(options: options).visitLintableFiles(with: visitor).flatMap { files in
+                if !options.quiet {
+                    let pluralSuffix = { (collection: [Any]) -> String in
+                        return collection.count != 1 ? "s" : ""
+                    }
+                    queuedPrintError("Done correcting \(files.count) file\(pluralSuffix(files))!")
                 }
-                queuedPrintError("Done correcting \(files.count) file\(pluralSuffix(files))!")
+                return .success(())
             }
-            return .success(())
+        case let .failure(error):
+            return .failure(error)
         }
     }
 }
@@ -62,22 +34,23 @@ struct AutoCorrectOptions: OptionsProtocol {
     let cachePath: String
     let ignoreCache: Bool
     let useTabs: Bool
+    let compilerLogPath: String
 
     // swiftlint:disable line_length
-    static func create(_ path: String) -> (_ configurationFile: String) -> (_ useScriptInputFiles: Bool) -> (_ quiet: Bool) -> (_ forceExclude: Bool) -> (_ format: Bool) -> (_ cachePath: String) -> (_ ignoreCache: Bool) -> (_ useTabs: Bool) -> (_ paths: [String]) -> AutoCorrectOptions {
-        return { configurationFile in { useScriptInputFiles in { quiet in { forceExclude in { format in { cachePath in { ignoreCache in { useTabs in { paths in
+    static func create(_ path: String) -> (_ configurationFile: String) -> (_ useScriptInputFiles: Bool) -> (_ quiet: Bool) -> (_ forceExclude: Bool) -> (_ format: Bool) -> (_ cachePath: String) -> (_ ignoreCache: Bool) -> (_ useTabs: Bool) -> (_ compilerLogPath: String) -> (_ paths: [String]) -> AutoCorrectOptions {
+        return { configurationFile in { useScriptInputFiles in { quiet in { forceExclude in { format in { cachePath in { ignoreCache in { useTabs in { compilerLogPath in { paths in
             let allPaths: [String]
             if !path.isEmpty {
                 allPaths = [path]
             } else {
                 allPaths = paths
             }
-            return self.init(paths: allPaths, configurationFile: configurationFile, useScriptInputFiles: useScriptInputFiles, quiet: quiet, forceExclude: forceExclude, format: format, cachePath: cachePath, ignoreCache: ignoreCache, useTabs: useTabs)
-        }}}}}}}}}
+            return self.init(paths: allPaths, configurationFile: configurationFile, useScriptInputFiles: useScriptInputFiles, quiet: quiet, forceExclude: forceExclude, format: format, cachePath: cachePath, ignoreCache: ignoreCache, useTabs: useTabs, compilerLogPath: compilerLogPath)
+            // swiftlint:enable line_length
+        }}}}}}}}}}
     }
 
     static func evaluate(_ mode: CommandMode) -> Result<AutoCorrectOptions, CommandantError<CommandantError<()>>> {
-        // swiftlint:enable line_length
         return create
             <*> mode <| pathOption(action: "correct")
             <*> mode <| configOption
@@ -96,7 +69,54 @@ struct AutoCorrectOptions: OptionsProtocol {
             <*> mode <| Option(key: "use-tabs",
                                defaultValue: false,
                                usage: "should use tabs over spaces when reformatting. Deprecated.")
+            <*> mode <| Option(key: "compiler-log-path", defaultValue: "",
+                               usage: """
+                                      the path of the full xcodebuild log to use when correcting CompilerArgumentRules
+                                      """)
             // This should go last to avoid eating other args
             <*> mode <| pathsArgument(action: "correct")
     }
+
+    fileprivate var visitor: Result<LintableFilesVisitor, CommandantError<()>> {
+        let configuration = Configuration(options: self)
+        let cache = ignoreCache ? nil : LinterCache(configuration: configuration)
+        let indentWidth: Int
+        var useTabs: Bool
+
+        switch configuration.indentation {
+        case .tabs:
+            indentWidth = 4
+            useTabs = true
+        case .spaces(let count):
+            indentWidth = count
+            useTabs = false
+        }
+
+        if useTabs {
+            queuedPrintError("'use-tabs' is deprecated and will be completely removed" +
+                " in a future release. 'indentation' can now be defined in a configuration file.")
+            useTabs = self.useTabs
+        }
+
+        let visitor = LintableFilesVisitor(paths: paths, action: "Correcting", useSTDIN: false, quiet: quiet,
+                                           useScriptInputFiles: useScriptInputFiles, forceExclude: forceExclude,
+                                           cache: cache, parallel: true, compilerLogPath: compilerLogPath) { linter in
+            let corrections = linter.correct()
+            if !corrections.isEmpty && !self.quiet {
+                let correctionLogs = corrections.map({ $0.consoleDescription })
+                queuedPrint(correctionLogs.joined(separator: "\n"))
+            }
+            if self.format {
+                linter.format(useTabs: useTabs, indentWidth: indentWidth)
+            }
+        }
+
+        if let visitor = visitor {
+            return .success(visitor)
+        }
+
+        return .failure(
+            .usageError(description: "Could not read compiler log at path: '\(compilerLogPath)'")
+        )
+    }
 }

Source/swiftlint/Commands/LintCommand.swift

@@ -130,18 +130,19 @@ struct LintOptions: OptionsProtocol {
     let cachePath: String
     let ignoreCache: Bool
     let enableAllRules: Bool
+    let compilerLogPath: String
 
     // swiftlint:disable line_length
-    static func create(_ path: String) -> (_ useSTDIN: Bool) -> (_ configurationFile: String) -> (_ strict: Bool) -> (_ lenient: Bool) -> (_ forceExclude: Bool) -> (_ useScriptInputFiles: Bool) -> (_ benchmark: Bool) -> (_ reporter: String) -> (_ quiet: Bool) -> (_ cachePath: String) -> (_ ignoreCache: Bool) -> (_ enableAllRules: Bool) -> (_ paths: [String]) -> LintOptions {
-        return { useSTDIN in { configurationFile in { strict in { lenient in { forceExclude in { useScriptInputFiles in { benchmark in { reporter in { quiet in { cachePath in { ignoreCache in { enableAllRules in { paths in
+    static func create(_ path: String) -> (_ useSTDIN: Bool) -> (_ configurationFile: String) -> (_ strict: Bool) -> (_ lenient: Bool) -> (_ forceExclude: Bool) -> (_ useScriptInputFiles: Bool) -> (_ benchmark: Bool) -> (_ reporter: String) -> (_ quiet: Bool) -> (_ cachePath: String) -> (_ ignoreCache: Bool) -> (_ enableAllRules: Bool) -> (_ compilerLogPath: String) -> (_ paths: [String]) -> LintOptions {
+        return { useSTDIN in { configurationFile in { strict in { lenient in { forceExclude in { useScriptInputFiles in { benchmark in { reporter in { quiet in { cachePath in { ignoreCache in { enableAllRules in { compilerLogPath in { paths in
             let allPaths: [String]
             if !path.isEmpty {
                 allPaths = [path]
             } else {
                 allPaths = paths
             }
-            return self.init(paths: allPaths, useSTDIN: useSTDIN, configurationFile: configurationFile, strict: strict, lenient: lenient, forceExclude: forceExclude, useScriptInputFiles: useScriptInputFiles, benchmark: benchmark, reporter: reporter, quiet: quiet, cachePath: cachePath, ignoreCache: ignoreCache, enableAllRules: enableAllRules)
-        }}}}}}}}}}}}}
+            return self.init(paths: allPaths, useSTDIN: useSTDIN, configurationFile: configurationFile, strict: strict, lenient: lenient, forceExclude: forceExclude, useScriptInputFiles: useScriptInputFiles, benchmark: benchmark, reporter: reporter, quiet: quiet, cachePath: cachePath, ignoreCache: ignoreCache, enableAllRules: enableAllRules, compilerLogPath: compilerLogPath)
+        }}}}}}}}}}}}}}
     }
 
     static func evaluate(_ mode: CommandMode) -> Result<LintOptions, CommandantError<CommandantError<()>>> {
@@ -170,6 +171,8 @@ struct LintOptions: OptionsProtocol {
                                usage: "ignore cache when linting")
             <*> mode <| Option(key: "enable-all-rules", defaultValue: false,
                                usage: "run all rules, even opt-in and disabled ones, ignoring `whitelist_rules`")
+            <*> mode <| Option(key: "compiler-log-path", defaultValue: "",
+                               usage: "the path of the full xcodebuild log to use when linting CompilerArgumentRules")
             // This should go last to avoid eating other args
             <*> mode <| pathsArgument(action: "lint")
     }

Source/swiftlint/Extensions/Configuration+CommandLine.swift

@@ -48,84 +48,92 @@ private func autoreleasepool(block: () -> Void) { block() }
 
 extension Configuration {
 
-    func visitLintableFiles(paths: [String], action: String, useSTDIN: Bool = false,
-                            quiet: Bool = false, useScriptInputFiles: Bool, forceExclude: Bool,
-                            cache: LinterCache? = nil, parallel: Bool = false,
-                            visitorBlock: @escaping (Linter) -> Void) -> Result<[File], CommandantError<()>> {
-        return getFiles(paths: paths, action: action, useSTDIN: useSTDIN, quiet: quiet, forceExclude: forceExclude,
-                        useScriptInputFiles: useScriptInputFiles)
-        .flatMap { files -> Result<[Configuration: [File]], CommandantError<()>> in
-            if files.isEmpty {
-                let errorMessage = "No lintable files found at paths: '\(paths.joined(separator: ", "))'"
-                return .failure(.usageError(description: errorMessage))
-            }
-            return .success(Dictionary(grouping: files, by: configuration(for:)))
-        }.flatMap { filesPerConfiguration in
-            let queue = DispatchQueue(label: "io.realm.swiftlint.indexIncrementer")
-            var index = 0
-            let fileCount = filesPerConfiguration.reduce(0) { $0 + $1.value.count }
-            let visit = { (file: File, config: Configuration) -> Void in
-                if !quiet, let path = file.path {
-                    let increment = {
-                        index += 1
-                        let filename = path.bridge().lastPathComponent
-                        queuedPrintError("\(action) '\(filename)' (\(index)/\(fileCount))")
-                    }
-                    if parallel {
-                        queue.sync(execute: increment)
-                    } else {
-                        increment()
-                    }
-                }
-                autoreleasepool {
-                    visitorBlock(Linter(file: file, configuration: config, cache: cache))
-                }
-            }
-            var filesAndConfigurations = [(File, Configuration)]()
-            filesAndConfigurations.reserveCapacity(fileCount)
-            for (config, files) in filesPerConfiguration {
-                let newConfig: Configuration
-                if cache != nil {
-                    newConfig = config.withPrecomputedCacheDescription()
-                } else {
-                    newConfig = config
-                }
-                filesAndConfigurations += files.map { ($0, newConfig) }
-            }
-            if parallel {
-                DispatchQueue.concurrentPerform(iterations: fileCount) { index in
-                    let (file, config) = filesAndConfigurations[index]
-                    visit(file, config)
-                }
-            } else {
-                filesAndConfigurations.forEach(visit)
-            }
-            return .success(filesAndConfigurations.compactMap({ $0.0 }))
-        }
+    func visitLintableFiles(with visitor: LintableFilesVisitor) -> Result<[File], CommandantError<()>> {
+        return getFiles(with: visitor)
+            .flatMap { groupFiles($0, visitor: visitor) }
+            .flatMap { visit(filesPerConfiguration: $0, visitor: visitor) }
     }
 
-    // swiftlint:disable function_parameter_count
-    fileprivate func getFiles(paths: [String], action: String, useSTDIN: Bool, quiet: Bool, forceExclude: Bool,
-                              useScriptInputFiles: Bool) -> Result<[File], CommandantError<()>> {
-        if useSTDIN {
+    private func groupFiles(_ files: [File],
+                            visitor: LintableFilesVisitor) -> Result<[Configuration: [File]], CommandantError<()>> {
+        if files.isEmpty {
+            let errorMessage = "No lintable files found at paths: '\(visitor.paths.joined(separator: ", "))'"
+            return .failure(.usageError(description: errorMessage))
+        }
+        return .success(Dictionary(grouping: files, by: configuration(for:)))
+    }
+
+    private func visit(filesPerConfiguration: [Configuration: [File]],
+                       visitor: LintableFilesVisitor) -> Result<[File], CommandantError<()>> {
+        let queue = DispatchQueue(label: "io.realm.swiftlint.indexIncrementer")
+        var index = 0
+        let fileCount = filesPerConfiguration.reduce(0) { $0 + $1.value.count }
+        let visit = { (file: File, config: Configuration) -> Void in
+            if !visitor.quiet, let path = file.path {
+                let increment = {
+                    index += 1
+                    let filename = path.bridge().lastPathComponent
+                    queuedPrintError("\(visitor.action) '\(filename)' (\(index)/\(fileCount))")
+                }
+                if visitor.parallel {
+                    queue.sync(execute: increment)
+                } else {
+                    increment()
+                }
+            }
+            autoreleasepool {
+                let compilerArguments = file.compilerArguments(compilerLogs: visitor.compilerLogContents)
+                let linter = Linter(file: file, configuration: config, cache: visitor.cache,
+                                    compilerArguments: compilerArguments)
+                visitor.block(linter)
+            }
+        }
+        var filesAndConfigurations = [(File, Configuration)]()
+        filesAndConfigurations.reserveCapacity(fileCount)
+        for (config, files) in filesPerConfiguration {
+            let newConfig: Configuration
+            if visitor.cache != nil {
+                newConfig = config.withPrecomputedCacheDescription()
+            } else {
+                newConfig = config
+            }
+            filesAndConfigurations += files.map { ($0, newConfig) }
+        }
+        if visitor.parallel {
+            DispatchQueue.concurrentPerform(iterations: fileCount) { index in
+                let (file, config) = filesAndConfigurations[index]
+                visit(file, config)
+            }
+        } else {
+            filesAndConfigurations.forEach(visit)
+        }
+        return .success(filesAndConfigurations.compactMap({ $0.0 }))
+    }
+
+    fileprivate func getFiles(with visitor: LintableFilesVisitor) -> Result<[File], CommandantError<()>> {
+        if visitor.useSTDIN {
             let stdinData = FileHandle.standardInput.readDataToEndOfFile()
             if let stdinString = String(data: stdinData, encoding: .utf8) {
                 return .success([File(contents: stdinString)])
             }
             return .failure(.usageError(description: "stdin isn't a UTF8-encoded string"))
-        } else if useScriptInputFiles {
+        } else if visitor.useScriptInputFiles {
             return scriptInputFiles()
         }
-        if !quiet {
-            let filesInfo = paths.isEmpty ? "in current working directory" : "at paths \(paths.joined(separator: ", "))"
-            let message = "\(action) Swift files \(filesInfo)"
-            queuedPrintError(message)
+        if !visitor.quiet {
+            let filesInfo: String
+            if visitor.paths.isEmpty {
+                filesInfo = "in current working directory"
+            } else {
+                filesInfo = "at paths \(visitor.paths.joined(separator: ", "))"
+            }
+
+            queuedPrintError("\(visitor.action) Swift files \(filesInfo)")
         }
-        return .success(paths.flatMap {
-            self.lintableFiles(inPath: $0, forceExclude: forceExclude)
+        return .success(visitor.paths.flatMap {
+            self.lintableFiles(inPath: $0, forceExclude: visitor.forceExclude)
         })
     }
-    // swiftlint:enable function_parameter_count
 
     private static func rootPath(from paths: [String]) -> String? {
         // We don't know the root when more than one path is passed (i.e. not useful if the root of 2 paths is ~)
@@ -146,10 +154,17 @@ extension Configuration {
 
     func visitLintableFiles(options: LintOptions, cache: LinterCache? = nil,
                             visitorBlock: @escaping (Linter) -> Void) -> Result<[File], CommandantError<()>> {
-        return visitLintableFiles(paths: options.paths, action: "Linting", useSTDIN: options.useSTDIN,
-                                  quiet: options.quiet, useScriptInputFiles: options.useScriptInputFiles,
-                                  forceExclude: options.forceExclude, cache: cache, parallel: true,
-                                  visitorBlock: visitorBlock)
+        let visitor = LintableFilesVisitor(paths: options.paths, action: "Linting", useSTDIN: options.useSTDIN,
+                                           quiet: options.quiet, useScriptInputFiles: options.useScriptInputFiles,
+                                           forceExclude: options.forceExclude, cache: cache, parallel: true,
+                                           compilerLogPath: options.compilerLogPath, block: visitorBlock)
+        if let visitor = visitor {
+            return visitLintableFiles(with: visitor)
+        }
+
+        return .failure(
+            .usageError(description: "Could not read compiler log at path: '\(options.compilerLogPath)'")
+        )
     }
 
     // MARK: AutoCorrect Command

Source/swiftlint/Extensions/File+CompilerArguments.swift

@@ -0,0 +1,136 @@
+import Foundation
+import SourceKittenFramework
+
+extension File {
+    /// Extracts compiler arguments for this file from the specified compiler logs.
+    ///
+    /// - parameter compilerLogs: xcodebuild log output from a clean & successful build (not incremental).
+    ///
+    /// - returns: The compiler arguments for this file, or an empty array if none were found.
+    func compilerArguments(compilerLogs: String) -> [String] {
+        return path.flatMap { path in
+            return compileCommand(compilerLogs: compilerLogs, sourceFile: path)
+        } ?? []
+    }
+}
+
+// MARK: - Private
+
+#if os(Linux)
+private extension Scanner {
+    func scanString(string: String) -> String? {
+        return scanString(string)
+    }
+}
+#else
+private extension Scanner {
+    func scanUpToString(_ string: String) -> String? {
+        var result: NSString?
+        let success = scanUpTo(string, into: &result)
+        if success {
+            return result?.bridge()
+        }
+        return nil
+    }
+
+    func scanString(string: String) -> String? {
+        var result: NSString?
+        let success = scanString(string, into: &result)
+        if success {
+            return result?.bridge()
+        }
+        return nil
+    }
+}
+#endif
+
+private func compileCommand(compilerLogs: String, sourceFile: String) -> [String]? {
+    let escapedSourceFile = sourceFile.replacingOccurrences(of: " ", with: "\\ ")
+    guard compilerLogs.contains(escapedSourceFile) else {
+        return nil
+    }
+
+    var compileCommand: [String]?
+    compilerLogs.enumerateLines { line, stop in
+        if line.contains(escapedSourceFile),
+            let swiftcIndex = line.range(of: "swiftc ")?.upperBound,
+            line.contains(" -module-name ") {
+            compileCommand = parseCLIArguments(String(line[swiftcIndex...]))
+            stop = true
+        }
+    }
+
+    return compileCommand
+}
+
+private func parseCLIArguments(_ string: String) -> [String] {
+    let escapedSpacePlaceholder = "\u{0}"
+    let scanner = Scanner(string: string)
+    var str = ""
+    var didStart = false
+    while let result = scanner.scanUpToString("\"") {
+        if didStart {
+            str += result.replacingOccurrences(of: " ", with: escapedSpacePlaceholder)
+            str += " "
+        } else {
+            str += result
+        }
+        _ = scanner.scanString(string: "\"")
+        didStart = !didStart
+    }
+    return filter(arguments:
+        str.trimmingCharacters(in: .whitespaces)
+            .replacingOccurrences(of: "\\ ", with: escapedSpacePlaceholder)
+            .components(separatedBy: " ")
+            .map { $0.replacingOccurrences(of: escapedSpacePlaceholder, with: " ") }
+    )
+}
+
+/**
+ Partially filters compiler arguments from `xcodebuild` to something that SourceKit/Clang will accept.
+
+ - parameter args: Compiler arguments, as parsed from `xcodebuild`.
+
+ - returns: A tuple of partially filtered compiler arguments in `.0`, and whether or not there are
+ more flags to remove in `.1`.
+ */
+private func partiallyFilter(arguments args: [String]) -> ([String], Bool) {
+    guard let indexOfFlagToRemove = args.index(of: "-output-file-map") else {
+        return (args, false)
+    }
+    var args = args
+    args.remove(at: args.index(after: indexOfFlagToRemove))
+    args.remove(at: indexOfFlagToRemove)
+    return (args, true)
+}
+
+/**
+ Filters compiler arguments from `xcodebuild` to something that SourceKit/Clang will accept.
+
+ - parameter args: Compiler arguments, as parsed from `xcodebuild`.
+
+ - returns: Filtered compiler arguments.
+ */
+private func filter(arguments args: [String]) -> [String] {
+    var args = args
+    args.append(contentsOf: ["-D", "DEBUG"])
+    var shouldContinueToFilterArguments = true
+    while shouldContinueToFilterArguments {
+        (args, shouldContinueToFilterArguments) = partiallyFilter(arguments: args)
+    }
+    return args.filter {
+        ![
+            "-parseable-output",
+            "-incremental",
+            "-serialize-diagnostics",
+            "-emit-dependencies"
+        ].contains($0)
+    }.map {
+        if $0 == "-O" {
+            return "-Onone"
+        } else if $0 == "-DNDEBUG=1" {
+            return "-DDEBUG=1"
+        }
+        return $0
+    }
+}

Source/swiftlint/Helpers/LintableFilesVisitor.swift

@@ -0,0 +1,43 @@
+import Foundation
+import SwiftLintFramework
+
+struct LintableFilesVisitor {
+    let paths: [String]
+    let action: String
+    let useSTDIN: Bool
+    let quiet: Bool
+    let useScriptInputFiles: Bool
+    let forceExclude: Bool
+    let cache: LinterCache?
+    let parallel: Bool
+    let compilerLogContents: String
+    let block: (Linter) -> Void
+
+    init?(paths: [String], action: String, useSTDIN: Bool, quiet: Bool, useScriptInputFiles: Bool, forceExclude: Bool,
+          cache: LinterCache?, parallel: Bool, compilerLogPath: String, block: @escaping (Linter) -> Void) {
+        self.paths = paths
+        self.action = action
+        self.useSTDIN = useSTDIN
+        self.quiet = quiet
+        self.useScriptInputFiles = useScriptInputFiles
+        self.forceExclude = forceExclude
+        self.cache = cache
+        self.parallel = parallel
+        self.compilerLogContents = LintableFilesVisitor.compilerLogContents(logPath: compilerLogPath)
+        self.block = block
+    }
+
+    private static func compilerLogContents(logPath: String) -> String {
+        if logPath.isEmpty {
+            return ""
+        }
+
+        if let data = FileManager.default.contents(atPath: logPath),
+            let logContents = String(data: data, encoding: .utf8) {
+            return logContents
+        }
+
+        print("couldn't read log file at path '\(logPath)'")
+        return ""
+    }
+}

SwiftLint.xcodeproj/project.pbxproj

@@ -142,7 +142,10 @@
 		8B01E50220A4349100C9233E /* FunctionParameterCountRuleTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 8B01E4FF20A4340A00C9233E /* FunctionParameterCountRuleTests.swift */; };
 		8F2CC1CB20A6A070006ED34F /* FileNameConfiguration.swift in Sources */ = {isa = PBXBuildFile; fileRef = 8F2CC1CA20A6A070006ED34F /* FileNameConfiguration.swift */; };
 		8F2CC1CD20A6A189006ED34F /* FileNameRuleTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 8F2CC1CC20A6A189006ED34F /* FileNameRuleTests.swift */; };
+		8F6AA75B211905B8009BA28A /* LintableFilesVisitor.swift in Sources */ = {isa = PBXBuildFile; fileRef = 8F6AA75A211905B8009BA28A /* LintableFilesVisitor.swift */; };
+		8F6AA75D21190830009BA28A /* File+CompilerArguments.swift in Sources */ = {isa = PBXBuildFile; fileRef = 8F6AA75C21190830009BA28A /* File+CompilerArguments.swift */; };
 		8F8050821FFE0CBB006F5B93 /* Configuration+IndentationStyle.swift in Sources */ = {isa = PBXBuildFile; fileRef = 8F8050811FFE0CBB006F5B93 /* Configuration+IndentationStyle.swift */; };
+		8FC8523B2117BDDE0015269B /* ExplicitSelfRule.swift in Sources */ = {isa = PBXBuildFile; fileRef = 8FC8523A2117BDDE0015269B /* ExplicitSelfRule.swift */; };
 		8FC9F5111F4B8E48006826C1 /* IsDisjointRule.swift in Sources */ = {isa = PBXBuildFile; fileRef = 8FC9F5101F4B8E48006826C1 /* IsDisjointRule.swift */; };
 		8FD216CC205584AF008ED13F /* CharacterSet+SwiftLint.swift in Sources */ = {isa = PBXBuildFile; fileRef = 8FD216CB205584AF008ED13F /* CharacterSet+SwiftLint.swift */; };
 		92CCB2D71E1EEFA300C8E5A3 /* UnusedOptionalBindingRule.swift in Sources */ = {isa = PBXBuildFile; fileRef = 92CCB2D61E1EEFA300C8E5A3 /* UnusedOptionalBindingRule.swift */; };
@@ -543,7 +546,10 @@
 		8B01E4FF20A4340A00C9233E /* FunctionParameterCountRuleTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = FunctionParameterCountRuleTests.swift; sourceTree = "<group>"; };
 		8F2CC1CA20A6A070006ED34F /* FileNameConfiguration.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = FileNameConfiguration.swift; sourceTree = "<group>"; };
 		8F2CC1CC20A6A189006ED34F /* FileNameRuleTests.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = FileNameRuleTests.swift; sourceTree = "<group>"; };
+		8F6AA75A211905B8009BA28A /* LintableFilesVisitor.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = LintableFilesVisitor.swift; sourceTree = "<group>"; };
+		8F6AA75C21190830009BA28A /* File+CompilerArguments.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "File+CompilerArguments.swift"; sourceTree = "<group>"; };
 		8F8050811FFE0CBB006F5B93 /* Configuration+IndentationStyle.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "Configuration+IndentationStyle.swift"; sourceTree = "<group>"; };
+		8FC8523A2117BDDE0015269B /* ExplicitSelfRule.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ExplicitSelfRule.swift; sourceTree = "<group>"; };
 		8FC9F5101F4B8E48006826C1 /* IsDisjointRule.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = IsDisjointRule.swift; sourceTree = "<group>"; };
 		8FD216CB205584AF008ED13F /* CharacterSet+SwiftLint.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = "CharacterSet+SwiftLint.swift"; sourceTree = "<group>"; };
 		92CCB2D61E1EEFA300C8E5A3 /* UnusedOptionalBindingRule.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = UnusedOptionalBindingRule.swift; sourceTree = "<group>"; };
@@ -989,6 +995,7 @@
 				D4470D581EB6B4D1008A1B2E /* EmptyEnumArgumentsRule.swift */,
 				D47079AC1DFE2FA700027086 /* EmptyParametersRule.swift */,
 				D47079A61DFCEB2D00027086 /* EmptyParenthesesWithTrailingClosureRule.swift */,
+				8FC8523A2117BDDE0015269B /* ExplicitSelfRule.swift */,
 				D4C4A34D1DEA877200E0E04C /* FileHeaderRule.swift */,
 				E88DEA931B099C0900A66CB0 /* IdentifierNameRule.swift */,
 				D4130D961E16183F00242361 /* IdentifierNameRuleExamples.swift */,
@@ -1310,6 +1317,7 @@
 			children = (
 				E802ECFF1C56A56000A35AE1 /* Benchmark.swift */,
 				E81FB3E31C6D507B00DC988F /* CommonOptions.swift */,
+				8F6AA75A211905B8009BA28A /* LintableFilesVisitor.swift */,
 			);
 			path = Helpers;
 			sourceTree = "<group>";
@@ -1428,6 +1436,7 @@
 			isa = PBXGroup;
 			children = (
 				E8B067801C13E49600E9E13F /* Configuration+CommandLine.swift */,
+				8F6AA75C21190830009BA28A /* File+CompilerArguments.swift */,
 				E86E2B2D1E17443B001E823C /* Reporter+CommandLine.swift */,
 				6C032EF02027F79F00CD7E8D /* shim.swift */,
 			);
@@ -1933,6 +1942,7 @@
 				B89F3BCF1FD5EE1400931E59 /* RequiredEnumCaseRuleConfiguration.swift in Sources */,
 				D48B51211F4F5DEF0068AB98 /* RuleList+Documentation.swift in Sources */,
 				8FC9F5111F4B8E48006826C1 /* IsDisjointRule.swift in Sources */,
+				8FC8523B2117BDDE0015269B /* ExplicitSelfRule.swift in Sources */,
 				4DCB8E7F1CBE494E0070FCF0 /* RegexHelpers.swift in Sources */,
 				E86396C21BADAAE5002C9E88 /* Reporter.swift in Sources */,
 				A1A6F3F21EE319ED00A9F9E2 /* ObjectLiteralConfiguration.swift in Sources */,
@@ -2021,6 +2031,7 @@
 			buildActionMask = 2147483647;
 			files = (
 				E86E2B2E1E17443B001E823C /* Reporter+CommandLine.swift in Sources */,
+				8F6AA75D21190830009BA28A /* File+CompilerArguments.swift in Sources */,
 				E8B067811C13E49600E9E13F /* Configuration+CommandLine.swift in Sources */,
 				E802ED001C56A56000A35AE1 /* Benchmark.swift in Sources */,
 				E83A0B351A5D382B0041A60A /* VersionCommand.swift in Sources */,
@@ -2031,6 +2042,7 @@
 				6C032EF12027F79F00CD7E8D /* shim.swift in Sources */,
 				D4DA1DFC1E19CD300037413D /* GenerateDocsCommand.swift in Sources */,
 				E84E07471C13F95300F11122 /* AutoCorrectCommand.swift in Sources */,
+				8F6AA75B211905B8009BA28A /* LintableFilesVisitor.swift in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};

Tests/LinuxMain.swift

@@ -332,6 +332,12 @@ extension ExplicitInitRuleTests {
     ]
 }
 
+extension ExplicitSelfRuleTests {
+    static var allTests: [(String, (ExplicitSelfRuleTests) -> () throws -> Void)] = [
+        ("testWithDefaultConfiguration", testWithDefaultConfiguration)
+    ]
+}
+
 extension ExplicitTopLevelACLRuleTests {
     static var allTests: [(String, (ExplicitTopLevelACLRuleTests) -> () throws -> Void)] = [
         ("testWithDefaultConfiguration", testWithDefaultConfiguration)
@@ -1274,6 +1280,7 @@ XCTMain([
     testCase(ExplicitACLRuleTests.allTests),
     testCase(ExplicitEnumRawValueRuleTests.allTests),
     testCase(ExplicitInitRuleTests.allTests),
+    testCase(ExplicitSelfRuleTests.allTests),
     testCase(ExplicitTopLevelACLRuleTests.allTests),
     testCase(ExplicitTypeInterfaceConfigurationTests.allTests),
     testCase(ExplicitTypeInterfaceRuleTests.allTests),

Tests/SwiftLintFrameworkTests/AutomaticRuleTests.generated.swift

@@ -174,6 +174,12 @@ class ExplicitInitRuleTests: XCTestCase {
     }
 }
 
+class ExplicitSelfRuleTests: XCTestCase {
+    func testWithDefaultConfiguration() {
+        verifyRule(ExplicitSelfRule.description)
+    }
+}
+
 class ExplicitTopLevelACLRuleTests: XCTestCase {
     func testWithDefaultConfiguration() {
         verifyRule(ExplicitTopLevelACLRule.description)

Tests/SwiftLintFrameworkTests/TestHelpers.swift

@@ -13,11 +13,41 @@ extension String {
 
 let allRuleIdentifiers = Array(masterRuleList.list.keys)
 
-func violations(_ string: String, config: Configuration = Configuration()!) -> [StyleViolation] {
+func violations(_ string: String, config: Configuration = Configuration()!,
+                requiresFileOnDisk: Bool = false) -> [StyleViolation] {
     File.clearCaches()
     let stringStrippingMarkers = string.replacingOccurrences(of: violationMarker, with: "")
-    let file = File(contents: stringStrippingMarkers)
-    return Linter(file: file, configuration: config).styleViolations
+    guard requiresFileOnDisk else {
+        let file = File(contents: stringStrippingMarkers)
+        let linter = Linter(file: file, configuration: config)
+        return linter.styleViolations
+    }
+
+    let file = temporaryFile(contents: stringStrippingMarkers)
+    let linter = linterWithCompilerArguments(file, config: config)
+    return linter.styleViolations.map { violation in
+        let locationWithoutFile = Location(file: nil,
+                                           line: violation.location.line,
+                                           character: violation.location.character)
+        return StyleViolation(ruleDescription: violation.ruleDescription, severity: violation.severity,
+                              location: locationWithoutFile, reason: violation.reason)
+    }
+}
+
+private func linterWithCompilerArguments(_ file: File, config: Configuration) -> Linter {
+    return Linter(file: file, configuration: config, compilerArguments: ["-j4", file.path!])
+}
+
+private func temporaryFile(contents: String) -> File {
+    let url = temporaryFileURL()!
+    _ = try? contents.data(using: .utf8)!.write(to: url)
+    return File(path: url.path)!
+}
+
+private func temporaryFileURL() -> URL? {
+    return URL(fileURLWithPath: NSTemporaryDirectory())
+        .appendingPathComponent(UUID().uuidString)
+        .appendingPathExtension("swift")
 }
 
 private func cleanedContentsAndMarkerOffsets(from contents: String) -> (String, [Int]) {
@@ -65,10 +95,9 @@ private func render(locations: [Location], in contents: String) -> String {
 
 private extension Configuration {
     func assertCorrection(_ before: String, expected: String) {
-        guard let path = NSURL(fileURLWithPath: NSTemporaryDirectory(), isDirectory: true)
-            .appendingPathComponent(NSUUID().uuidString + ".swift")?.path else {
-                XCTFail("couldn't generate temporary path for assertCorrection()")
-                return
+        guard let path = temporaryFileURL()?.path else {
+            XCTFail("couldn't generate temporary path for assertCorrection()")
+            return
         }
         let (cleanedBefore, markerOffsets) = cleanedContentsAndMarkerOffsets(from: before)
         do {
@@ -83,7 +112,7 @@ private extension Configuration {
         }
         // expectedLocations are needed to create before call `correct()`
         let expectedLocations = markerOffsets.map { Location(file: file, characterOffset: $0) }
-        let corrections = Linter(file: file, configuration: self).correct().sorted {
+        let corrections = linterWithCompilerArguments(file, config: self).correct().sorted {
             $0.location < $1.location
         }
         if expectedLocations.isEmpty {
@@ -152,6 +181,10 @@ extension XCTestCase {
                     skipDisableCommandTests: Bool = false,
                     testMultiByteOffsets: Bool = true,
                     testShebang: Bool = true) {
+        guard SwiftVersion.current >= ruleDescription.minSwiftVersion else {
+            return
+        }
+
         guard let config = makeConfig(ruleConfiguration,
                                       ruleDescription.identifier,
                                       skipDisableCommandTests: skipDisableCommandTests) else {
@@ -159,40 +192,6 @@ extension XCTestCase {
             return
         }
 
-        guard SwiftVersion.current >= ruleDescription.minSwiftVersion else {
-            return
-        }
-
-        let triggers = ruleDescription.triggeringExamples
-        let nonTriggers = ruleDescription.nonTriggeringExamples
-        verifyExamples(triggers: triggers, nonTriggers: nonTriggers, configuration: config)
-
-        if testMultiByteOffsets {
-            verifyExamples(triggers: triggers.map(addEmoji),
-                           nonTriggers: nonTriggers.map(addEmoji), configuration: config)
-        }
-
-        if testShebang {
-            verifyExamples(triggers: triggers.map(addShebang),
-                           nonTriggers: nonTriggers.map(addShebang), configuration: config)
-        }
-
-        // Comment doesn't violate
-        if !skipCommentTests {
-            XCTAssertEqual(
-                triggers.flatMap({ violations("/*\n  " + $0 + "\n */", config: config) }).count,
-                commentDoesntViolate ? 0 : triggers.count
-            )
-        }
-
-        // String doesn't violate
-        if !skipStringTests {
-            XCTAssertEqual(
-                triggers.flatMap({ violations($0.toStringLiteral(), config: config) }).count,
-                stringDoesntViolate ? 0 : triggers.count
-            )
-        }
-
         let disableCommands: [String]
         if skipDisableCommandTests {
             disableCommands = []
@@ -200,18 +199,75 @@ extension XCTestCase {
             disableCommands = ruleDescription.allIdentifiers.map { "// swiftlint:disable \($0)\n" }
         }
 
-        // "disable" commands doesn't violate
-        for command in disableCommands {
-            XCTAssert(triggers.flatMap({ violations(command + $0, config: config) }).isEmpty)
+        self.verifyLint(ruleDescription, config: config, commentDoesntViolate: commentDoesntViolate,
+                        stringDoesntViolate: stringDoesntViolate, skipCommentTests: skipCommentTests,
+                        skipStringTests: skipStringTests, disableCommands: disableCommands,
+                        testMultiByteOffsets: testMultiByteOffsets, testShebang: testShebang)
+        self.verifyCorrections(ruleDescription, config: config, disableCommands: disableCommands,
+                               testMultiByteOffsets: testMultiByteOffsets)
+    }
+
+    func verifyLint(_ ruleDescription: RuleDescription,
+                    config: Configuration,
+                    commentDoesntViolate: Bool = true,
+                    stringDoesntViolate: Bool = true,
+                    skipCommentTests: Bool = false,
+                    skipStringTests: Bool = false,
+                    disableCommands: [String] = [],
+                    testMultiByteOffsets: Bool = true,
+                    testShebang: Bool = true) {
+        func verify(triggers: [String], nonTriggers: [String]) {
+            verifyExamples(triggers: triggers, nonTriggers: nonTriggers, configuration: config,
+                           requiresFileOnDisk: ruleDescription.requiresFileOnDisk)
         }
 
+        let triggers = ruleDescription.triggeringExamples
+        let nonTriggers = ruleDescription.nonTriggeringExamples
+        verify(triggers: triggers, nonTriggers: nonTriggers)
+
+        if testMultiByteOffsets {
+            verify(triggers: triggers.map(addEmoji), nonTriggers: nonTriggers.map(addEmoji))
+        }
+
+        if testShebang {
+            verify(triggers: triggers.map(addShebang), nonTriggers: nonTriggers.map(addShebang))
+        }
+
+        func makeViolations(_ string: String) -> [StyleViolation] {
+            return violations(string, config: config, requiresFileOnDisk: ruleDescription.requiresFileOnDisk)
+        }
+
+        // Comment doesn't violate
+        if !skipCommentTests {
+            XCTAssertEqual(
+                triggers.flatMap({ makeViolations("/*\n  " + $0 + "\n */") }).count,
+                commentDoesntViolate ? 0 : triggers.count
+            )
+        }
+
+        // String doesn't violate
+        if !skipStringTests {
+            XCTAssertEqual(
+                triggers.flatMap({ makeViolations($0.toStringLiteral()) }).count,
+                stringDoesntViolate ? 0 : triggers.count
+            )
+        }
+
+        // "disable" commands doesn't violate
+        for command in disableCommands {
+            XCTAssert(triggers.flatMap({ makeViolations(command + $0) }).isEmpty)
+        }
+    }
+
+    func verifyCorrections(_ ruleDescription: RuleDescription, config: Configuration,
+                           disableCommands: [String], testMultiByteOffsets: Bool) {
         // corrections
         ruleDescription.corrections.forEach {
             testCorrection($0, configuration: config, testMultiByteOffsets: testMultiByteOffsets)
         }
         // make sure strings that don't trigger aren't corrected
-        zip(nonTriggers, nonTriggers).forEach {
-            testCorrection($0, configuration: config, testMultiByteOffsets: testMultiByteOffsets)
+        ruleDescription.nonTriggeringExamples.forEach {
+            testCorrection(($0, $0), configuration: config, testMultiByteOffsets: testMultiByteOffsets)
         }
 
         // "disable" commands do not correct
@@ -222,14 +278,14 @@ extension XCTestCase {
                 config.assertCorrection(expectedCleaned, expected: expectedCleaned)
             }
         }
-
     }
 
     private func verifyExamples(triggers: [String], nonTriggers: [String],
-                                configuration config: Configuration) {
+                                configuration config: Configuration, requiresFileOnDisk: Bool) {
         // Non-triggering examples don't violate
         for nonTrigger in nonTriggers {
-            let unexpectedViolations = violations(nonTrigger, config: config)
+            let unexpectedViolations = violations(nonTrigger, config: config,
+                                                  requiresFileOnDisk: requiresFileOnDisk)
             if unexpectedViolations.isEmpty { continue }
             let nonTriggerWithViolations = render(violations: unexpectedViolations, in: nonTrigger)
             XCTFail("nonTriggeringExample violated: \n\(nonTriggerWithViolations)")
@@ -237,7 +293,8 @@ extension XCTestCase {
 
         // Triggering examples violate
         for trigger in triggers {
-            let triggerViolations = violations(trigger, config: config)
+            let triggerViolations = violations(trigger, config: config,
+                                               requiresFileOnDisk: requiresFileOnDisk)
 
             // Triggering examples with violation markers violate at the marker's location
             let (cleanTrigger, markerOffsets) = cleanedContentsAndMarkerOffsets(from: trigger)

Tests/SwiftLintFrameworkTests/TrailingCommaRuleTests.swift

@@ -84,6 +84,6 @@ class TrailingCommaRuleTests: XCTestCase {
 
     private func trailingCommaViolations(_ string: String, ruleConfiguration: Any? = nil) -> [StyleViolation] {
         let config = makeConfig(ruleConfiguration, TrailingCommaRule.description.identifier)!
-        return SwiftLintFrameworkTests.violations(string, config: config)
+        return violations(string, config: config)
     }
 }