Fix rebase

.swiftlint.yml

@@ -36,7 +36,6 @@ opt_in_rules:
   - last_where
   - legacy_multiple
   - legacy_random
-  - let_var_whitespace
   - literal_expression_end_indentation
   - lower_acl_than_parent
   - modifier_order

CHANGELOG.md

@@ -39,6 +39,19 @@
   [Bryan Ricker](https://github.com/bricker)
   [#3426](https://github.com/realm/SwiftLint/pull/3426)
 
+* The command line syntax has slightly changed due to migrating from the
+  Commandant command line parsing library to swift-argument-parser.
+  For the most part the breaking changes are all to make the syntax more
+  unix compliant and intuitive to use. For example, commands such as
+  `swiftlint --help` or `swiftlint -h` now work as expected.
+  The help output from various commands has greatly improved as well.
+  Notably: `swiftlint autocorrect` was removed in favor of
+  `swiftlint --fix`.
+  Previous commands should continue to work temporarily to help with the
+  transition. Please let us know if there's a command that no longer
+  works and we'll attempt to add a bridge to help with its transition.  
+  [JP Simard](https://github.com/jpsim)
+
 #### Experimental
 
 * None.
@@ -250,6 +263,9 @@
   enable it to detect more occurrences of unused declarations.  
   [JP Simard](https://github.com/jpsim)
 
+* Make the `unused_import` rule run about 2 times faster.  
+  [JP Simard](https://github.com/jpsim)
+
 * Remove unneeded internal locking overhead, leading to increased
   performance in multithreaded operations.  
   [JP Simard](https://github.com/jpsim)

Package.resolved

@@ -1,40 +1,22 @@
 {
   "object": {
     "pins": [
-      {
-        "package": "Commandant",
-        "repositoryURL": "https://github.com/Carthage/Commandant.git",
-        "state": {
-          "branch": null,
-          "revision": "ab68611013dec67413628ac87c1f29e8427bc8e4",
-          "version": "0.17.0"
-        }
-      },
-      {
-        "package": "Nimble",
-        "repositoryURL": "https://github.com/Quick/Nimble.git",
-        "state": {
-          "branch": null,
-          "revision": "7a46a5fc86cb917f69e3daf79fcb045283d8f008",
-          "version": "8.1.2"
-        }
-      },
-      {
-        "package": "Quick",
-        "repositoryURL": "https://github.com/Quick/Quick.git",
-        "state": {
-          "branch": null,
-          "revision": "09b3becb37cb2163919a3842a4c5fa6ec7130792",
-          "version": "2.2.1"
-        }
-      },
       {
         "package": "SourceKitten",
         "repositoryURL": "https://github.com/jpsim/SourceKitten.git",
         "state": {
           "branch": null,
-          "revision": "c0f960f72fa1e6151695074ffa696e4da6c45ce8",
-          "version": "0.30.1"
+          "revision": "7f4be006fe73211b0fd9666c73dc2f2303ffa756",
+          "version": "0.31.0"
+        }
+      },
+      {
+        "package": "swift-argument-parser",
+        "repositoryURL": "https://github.com/apple/swift-argument-parser.git",
+        "state": {
+          "branch": null,
+          "revision": "92646c0cdbaca076c8d3d0207891785b3379cbff",
+          "version": "0.3.1"
         }
       },
       {

Package.swift

@@ -1,4 +1,4 @@
-// swift-tools-version:5.0
+// swift-tools-version:5.2
 import PackageDescription
 
 #if canImport(CommonCrypto)
@@ -14,8 +14,8 @@ let package = Package(
         .library(name: "SwiftLintFramework", targets: ["SwiftLintFramework"])
     ],
     dependencies: [
-        .package(url: "https://github.com/Carthage/Commandant.git", .upToNextMinor(from: "0.17.0")),
-        .package(url: "https://github.com/jpsim/SourceKitten.git", .upToNextMinor(from: "0.30.1")),
+        .package(name: "swift-argument-parser", url: "https://github.com/apple/swift-argument-parser.git", .upToNextMinor(from: "0.3.1")),
+        .package(url: "https://github.com/jpsim/SourceKitten.git", .upToNextMinor(from: "0.31.0")),
         .package(url: "https://github.com/jpsim/Yams.git", from: "4.0.2"),
         .package(url: "https://github.com/scottrhoyt/SwiftyTextTable.git", from: "0.9.0"),
     ] + (addCryptoSwift ? [.package(url: "https://github.com/krzyzanowskim/CryptoSwift.git", .upToNextMinor(from: "1.3.2"))] : []),
@@ -23,7 +23,7 @@ let package = Package(
         .target(
             name: "swiftlint",
             dependencies: [
-                "Commandant",
+                .product(name: "ArgumentParser", package: "swift-argument-parser"),
                 "SwiftLintFramework",
                 "SwiftyTextTable",
             ]
@@ -31,7 +31,7 @@ let package = Package(
         .target(
             name: "SwiftLintFramework",
             dependencies: [
-                "SourceKittenFramework",
+                .product(name: "SourceKittenFramework", package: "SourceKitten"),
                 "Yams",
             ] + (addCryptoSwift ? ["CryptoSwift"] : [])
         ),

Source/SwiftLintFramework/Extensions/Array+SwiftLint.swift

@@ -30,6 +30,22 @@ extension Array where Element: Hashable {
     }
 }
 
+extension Array {
+    func unique<T: Hashable>(by transform: ((Element) -> T)) -> [Element] {
+        var set = Set<T>()
+        var result = [Element]()
+        for value in self {
+            let transformed = transform(value)
+            if !set.contains(transformed) {
+                set.insert(transformed)
+                result.append(value)
+            }
+        }
+
+        return result
+    }
+}
+
 extension Array {
     static func array(of obj: Any?) -> [Element]? {
         if let array = obj as? [Element] {

Source/SwiftLintFramework/Extensions/Dictionary+SwiftLint.swift

@@ -133,6 +133,22 @@ public struct SourceKittenDictionary {
         return value["key.column"] as? Int64
     }
 
+    /// The USR for this declaration.
+    var usr: String? {
+        return value["key.usr"] as? String
+    }
+
+    /// The annotated declaration.
+    var annotatedDeclaration: String? {
+        return value["key.annotated_decl"] as? String
+    }
+
+    // The dependencies returned in an index response.
+    var dependencies: [SourceKittenDictionary]? {
+        return (value["key.dependencies"] as? [[String: SourceKitRepresentable]])?
+            .map(SourceKittenDictionary.init)
+    }
+
     /// The `SwiftDeclarationAttributeKind` values associated with this dictionary.
     var enclosedSwiftAttributes: [SwiftDeclarationAttributeKind] {
         return swiftAttributes.compactMap { $0.attribute }

Source/SwiftLintFramework/Extensions/String+SwiftLint.swift

@@ -118,3 +118,16 @@ extension String {
         }
     }
 }
+
+extension StringView {
+    /// Converts a line and column pair to a ByteCount offset into the string.
+    ///
+    /// - parameter line:   The 1-indexed line number into the string.
+    /// - parameter column: The 1-indexed column number into the string.
+    ///
+    /// - returns: The `ByteCount` offset in bytes into the string.
+    func byteOffset(forLine line: Int, column: Int) -> ByteCount {
+        guard line > 0 else { return ByteCount(column - 1) }
+        return lines[line - 1].byteRange.location + ByteCount(column - 1)
+    }
+}

Source/SwiftLintFramework/Extensions/SyntaxKind+SwiftLint.swift

@@ -19,22 +19,4 @@ extension SyntaxKind {
                                             .docComment, .docCommentField, .identifier, .keyword, .number,
                                             .objectLiteral, .parameter, .placeholder, .string,
                                             .stringInterpolationAnchor, .typeidentifier]
-
-    /// Syntax kinds that don't have associated module info when getting their cursor info.
-    static var kindsWithoutModuleInfo: Set<SyntaxKind> {
-        return [
-            .attributeBuiltin,
-            .keyword,
-            .number,
-            .docComment,
-            .string,
-            .stringInterpolationAnchor,
-            .attributeID,
-            .buildconfigKeyword,
-            .buildconfigID,
-            .commentURL,
-            .comment,
-            .docCommentField
-        ]
-    }
 }

Source/SwiftLintFramework/Models/SwiftLintFile.swift

@@ -75,6 +75,20 @@ public final class SwiftLintFile {
 
         return containsAttributesRequiringFoundation(dict: structureDictionary)
     }
+
+    /// Returns the SourceKit index for the current file, obtained with the specified compiler arguments.
+    ///
+    /// - parameter compilerArguments: The swiftc arguments needed to compile the file.
+    ///
+    /// - returns: A `SourceKittenDictionary` with the index response.
+    func index(compilerArguments: [String]) -> SourceKittenDictionary? {
+        return path
+            .flatMap { path in
+                try? Request.index(file: path, arguments: compilerArguments)
+                            .sendIfNotDisabled()
+            }
+            .map(SourceKittenDictionary.init)
+    }
 }
 
 // MARK: - Hashable Conformance

Source/SwiftLintFramework/Rules/Lint/UnusedDeclarationRule.swift

@@ -91,15 +91,6 @@ public struct UnusedDeclarationRule: AutomaticTestableRule, ConfigurationProvide
 // MARK: - File Extensions
 
 private extension SwiftLintFile {
-    func index(compilerArguments: [String]) -> SourceKittenDictionary? {
-        return path
-            .flatMap { path in
-                try? Request.index(file: path, arguments: compilerArguments)
-                            .send()
-            }
-            .map(SourceKittenDictionary.init)
-    }
-
     func referencedUSRs(index: SourceKittenDictionary) -> Set<String> {
         return Set(index.traverseEntities { entity -> String? in
             if let usr = entity.usr,
@@ -224,14 +215,6 @@ private extension SwiftLintFile {
 }
 
 private extension SourceKittenDictionary {
-    var usr: String? {
-        return value["key.usr"] as? String
-    }
-
-    var annotatedDeclaration: String? {
-        return value["key.annotated_decl"] as? String
-    }
-
     var isImplicit: Bool {
         return value["key.is_implicit"] as? Bool == true
     }
@@ -321,10 +304,3 @@ private extension SourceKittenDictionary {
         }
     }
 }
-
-private extension StringView {
-    func byteOffset(forLine line: Int, column: Int) -> ByteCount {
-        guard line > 0 else { return ByteCount(column - 1) }
-        return lines[line - 1].byteRange.location + ByteCount(column - 1)
-    }
-}

Source/SwiftLintFramework/Rules/Lint/UnusedImportRule.swift

@@ -98,7 +98,12 @@ public struct UnusedImportRule: CorrectableRule, ConfigurationProviderRule, Anal
 
 private extension SwiftLintFile {
     func getImportUsage(compilerArguments: [String], configuration: UnusedImportConfiguration) -> [ImportUsage] {
-        var (imports, usrFragments) = getImportsAndUSRFragments(compilerArguments: compilerArguments)
+        guard let index = index(compilerArguments: compilerArguments) else {
+            queuedPrintError("Could not get index")
+            return []
+        }
+
+        var (imports, usrFragments) = getImportsAndUSRFragments(index: index, compilerArguments: compilerArguments)
 
         // Always disallow 'import Swift' because it's available without importing.
         usrFragments.remove("Swift")
@@ -108,15 +113,6 @@ private extension SwiftLintFile {
             unusedImports.remove("Foundation")
         }
 
-        if unusedImports.isNotEmpty {
-            unusedImports.subtract(
-                operatorImports(
-                    arguments: compilerArguments,
-                    processedTokenOffsets: Set(syntaxMap.tokens.map { $0.offset })
-                )
-            )
-        }
-
         let contentsNSString = stringView.nsString
         let unusedImportUsages = rangedAndSortedUnusedImports(of: Array(unusedImports), contents: contentsNSString)
             .map { ImportUsage.unused(module: $0, range: $1) }
@@ -143,42 +139,88 @@ private extension SwiftLintFile {
         return unusedImportUsages + missingImports.sorted().map { .missing(module: $0) }
     }
 
-    func getImportsAndUSRFragments(compilerArguments: [String]) -> (imports: Set<String>, usrFragments: Set<String>) {
-        var imports = Set<String>()
+    func getImportsAndUSRFragments(index: SourceKittenDictionary, compilerArguments: [String])
+        -> (imports: Set<String>, usrFragments: Set<String>) {
         var usrFragments = Set<String>()
-        var nextIsModuleImport = false
-        for token in syntaxMap.tokens {
-            guard let tokenKind = token.kind else {
-                continue
+
+        let allEntities = flatEntities(entity: index)
+
+        let referenceEntities = allEntities.filter { entity in
+            entity.kind?.starts(with: "source.lang.swift.ref") == true &&
+                entity.kind != "source.lang.swift.ref.module"
+        }
+
+        // swiftlint:disable:next nesting - We really shouldn't trigger when these nested types are in functions
+        struct Reference {
+            let line, column: Int
+            let usr: String
+        }
+
+        let dedupedReferences = referenceEntities
+            .compactMap { entity in
+                entity.line.flatMap { line in
+                    entity.column.flatMap { column in
+                        entity.usr.map { usr in
+                            Reference(line: Int(line), column: Int(column), usr: usr)
+                        }
+                    }
+                }
             }
-            if tokenKind == .keyword, contents(for: token) == "import" {
-                nextIsModuleImport = true
-                continue
-            }
-            if SyntaxKind.kindsWithoutModuleInfo.contains(tokenKind) {
-                continue
-            }
-            let cursorInfoRequest = Request.cursorInfo(file: path!, offset: token.offset,
-                                                       arguments: compilerArguments)
+            // don't cursor-info the same USR at different locations
+            .unique(by: { $0.usr })
+
+        var seenUSRs = Set<String>()
+        for reference in dedupedReferences {
+            let nameOffset = stringView.byteOffset(forLine: reference.line, column: reference.column)
+            let usr = reference.usr
+
+            let cursorInfoRequest = Request.cursorInfo(file: path!, offset: nameOffset, arguments: compilerArguments)
             guard let cursorInfo = (try? cursorInfoRequest.sendIfNotDisabled()).map(SourceKittenDictionary.init) else {
                 queuedPrintError("Could not get cursor info")
                 continue
             }
-            if nextIsModuleImport {
-                if let importedModule = cursorInfo.moduleName,
-                    cursorInfo.kind == "source.lang.swift.ref.module" {
-                    imports.insert(importedModule)
-                    nextIsModuleImport = false
+
+            if cursorInfo.usr == usr {
+                seenUSRs.insert(usr)
+                if let rootModuleName = cursorInfo.moduleName?.split(separator: ".").first.map(String.init) {
+                    usrFragments.insert(rootModuleName)
+                }
+            } else {
+                let tokens = syntaxMap.tokens
+                guard let firstTokenIndexAfterNameOffset = tokens.firstIndex(where: { $0.offset > nameOffset }) else {
+                    queuedPrintError("Could not get tokens")
                     continue
-                } else {
-                    nextIsModuleImport = false
+                }
+
+                var extraTokensToCheck = 3
+                let tokensAfterNameOffset = tokens.suffix(from: firstTokenIndexAfterNameOffset)
+                for token in tokensAfterNameOffset {
+                    extraTokensToCheck -= 1
+                    if extraTokensToCheck == 0 {
+                        break
+                    }
+
+                    let tokenCursorInfoRequest = Request.cursorInfo(file: path!, offset: token.offset,
+                                                                    arguments: compilerArguments)
+                    let tokenCursorInfo = (try? tokenCursorInfoRequest.sendIfNotDisabled())
+                        .map(SourceKittenDictionary.init)
+                    if tokenCursorInfo?.usr == usr {
+                        seenUSRs.insert(usr)
+                        if let rootModuleName = tokenCursorInfo?.moduleName?.split(separator: ".").first.map(String.init) {
+                            usrFragments.insert(rootModuleName)
+                            break
+                        }
+                    }
                 }
             }
-
-            appendUsedImports(cursorInfo: cursorInfo, usrFragments: &usrFragments)
         }
 
-        return (imports: imports, usrFragments: usrFragments)
+        let imports = index.dependencies?
+            .filter { $0.kind?.starts(with: "source.lang.swift.import.module") == true }
+            .compactMap { $0.name }
+            .filter { $0 != "Swift" }
+
+        return (imports: Set(imports ?? []), usrFragments: usrFragments)
     }
 
     func rangedAndSortedUnusedImports(of unusedImports: [String], contents: NSString) -> [(String, NSRange)] {
@@ -189,42 +231,6 @@ private extension SwiftLintFile {
             .sorted(by: { $0.1.location < $1.1.location })
     }
 
-    // Operators are omitted in the editor.open request and thus have to be looked up by the indexsource request
-    func operatorImports(arguments: [String], processedTokenOffsets: Set<ByteCount>) -> Set<String> {
-        guard let index = (try? Request.index(file: path!, arguments: arguments).sendIfNotDisabled())
-            .map(SourceKittenDictionary.init) else {
-            queuedPrintError("Could not get index")
-            return []
-        }
-
-        let operatorEntities = flatEntities(entity: index).filter { mightBeOperator(kind: $0.kind) }
-        let offsetPerLine = self.offsetPerLine()
-        var imports = Set<String>()
-
-        for entity in operatorEntities {
-            if
-                let line = entity.line,
-                let column = entity.column,
-                let lineOffset = offsetPerLine[Int(line) - 1] {
-                let offset = lineOffset + column - 1
-
-                // Filter already processed tokens such as static methods that are not operators
-                guard !processedTokenOffsets.contains(ByteCount(offset)) else { continue }
-
-                let cursorInfoRequest = Request.cursorInfo(file: path!, offset: ByteCount(offset), arguments: arguments)
-                guard let cursorInfo = (try? cursorInfoRequest.sendIfNotDisabled())
-                    .map(SourceKittenDictionary.init) else {
-                    queuedPrintError("Could not get cursor info")
-                    continue
-                }
-
-                appendUsedImports(cursorInfo: cursorInfo, usrFragments: &imports)
-            }
-        }
-
-        return imports
-    }
-
     func flatEntities(entity: SourceKittenDictionary) -> [SourceKittenDictionary] {
         let entities = entity.entities
         if entities.isEmpty {
@@ -233,34 +239,4 @@ private extension SwiftLintFile {
             return [entity] + entities.flatMap { flatEntities(entity: $0) }
         }
     }
-
-    func offsetPerLine() -> [Int: Int64] {
-        return Dictionary(
-            uniqueKeysWithValues: contents.bridge()
-                .components(separatedBy: "\n")
-                .map { Int64($0.bridge().lengthOfBytes(using: .utf8)) }
-                .reduce(into: [0]) { result, length in
-                    let newLineCharacterLength = Int64(1)
-                    let lineLength = length + newLineCharacterLength
-                    result.append(contentsOf: [(result.last ?? 0) + lineLength])
-                }
-                .enumerated()
-                .map { ($0.offset, $0.element) }
-        )
-    }
-
-    // Operators that are a part of some body are reported as method.static
-    func mightBeOperator(kind: String?) -> Bool {
-        guard let kind = kind else { return false }
-        return [
-            "source.lang.swift.ref.function.operator",
-            "source.lang.swift.ref.function.method.static"
-        ].contains { kind.hasPrefix($0) }
-    }
-
-    func appendUsedImports(cursorInfo: SourceKittenDictionary, usrFragments: inout Set<String>) {
-        if let rootModuleName = cursorInfo.moduleName?.split(separator: ".").first.map(String.init) {
-            usrFragments.insert(rootModuleName)
-        }
-    }
 }

Source/SwiftLintFramework/Rules/Style/ExplicitSelfRule.swift

@@ -261,11 +261,6 @@ private extension SwiftLintFile {
 }
 
 private extension StringView {
-    func byteOffset(forLine line: Int, column: Int) -> ByteCount {
-        guard line > 0 else { return ByteCount(column - 1) }
-        return lines[line - 1].byteRange.location + ByteCount(column - 1)
-    }
-
     func recursiveByteOffsets(_ dict: [String: Any]) -> [ByteCount] {
         let cur: [ByteCount]
         if let line = dict["key.line"] as? Int64,

Source/swiftlint/Commands/Analyze.swift

@@ -0,0 +1,59 @@
+import ArgumentParser
+
+extension SwiftLint {
+    struct Analyze: ParsableCommand {
+        static let configuration = CommandConfiguration(abstract: "Run analysis rules")
+
+        @OptionGroup
+        var common: LintOrAnalyzeArguments
+        @Option(help: pathOptionDescription(for: .analyze))
+        var path: String?
+        @Flag(help: quietOptionDescription(for: .analyze))
+        var quiet = false
+        @Option(help: "The path of the full xcodebuild log to use when running AnalyzerRules.")
+        var compilerLogPath: String?
+        @Option(help: "The path of a compilation database to use when running AnalyzerRules.")
+        var compileCommands: String?
+        @Argument(help: pathsArgumentDescription(for: .analyze))
+        var paths = [String]()
+
+        mutating func run() throws {
+            let allPaths: [String]
+            if let path = path {
+                allPaths = [path]
+            } else if !paths.isEmpty {
+                allPaths = paths
+            } else {
+                allPaths = [""] // Analyze files in current working directory if no paths were specified.
+            }
+            let options = LintOrAnalyzeOptions(
+                mode: .analyze,
+                paths: allPaths,
+                useSTDIN: false,
+                configurationFiles: common.config,
+                strict: common.leniency == .strict,
+                lenient: common.leniency == .lenient,
+                forceExclude: common.forceExclude,
+                useExcludingByPrefix: common.useAlternativeExcluding,
+                useScriptInputFiles: common.useScriptInputFiles,
+                benchmark: common.benchmark,
+                reporter: common.reporter,
+                quiet: quiet,
+                cachePath: nil,
+                ignoreCache: true,
+                enableAllRules: false,
+                autocorrect: common.fix,
+                compilerLogPath: compilerLogPath,
+                compileCommands: compileCommands
+            )
+
+            let result = LintOrAnalyzeCommand.run(options)
+            switch result {
+            case .success:
+                return
+            case .failure(let error):
+                throw error
+            }
+        }
+    }
+}

Source/swiftlint/Commands/AnalyzeCommand.swift

@@ -1,98 +0,0 @@
-import Commandant
-import SwiftLintFramework
-
-struct AnalyzeCommand: CommandProtocol {
-    let verb = "analyze"
-    let function = "[Experimental] Run analysis rules"
-
-    func run(_ options: AnalyzeOptions) -> Result<(), CommandantError<()>> {
-        let options = LintOrAnalyzeOptions(options)
-        if options.autocorrect {
-            return autocorrect(options)
-        } else {
-            return LintOrAnalyzeCommand.run(options)
-        }
-    }
-
-    private func autocorrect(_ options: LintOrAnalyzeOptions) -> Result<(), CommandantError<()>> {
-        let storage = RuleStorage()
-        let configuration = Configuration(options: options)
-        return configuration.visitLintableFiles(options: options, cache: nil, storage: storage) { linter in
-            let corrections = linter.correct(using: storage)
-            if !corrections.isEmpty && !options.quiet {
-                let correctionLogs = corrections.map({ $0.consoleDescription })
-                queuedPrint(correctionLogs.joined(separator: "\n"))
-            }
-        }.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))!")
-            }
-            return .success(())
-        }
-    }
-}
-
-struct AnalyzeOptions: OptionsProtocol {
-    let paths: [String]
-    let configurationFiles: [String]
-    let strict: Bool
-    let lenient: Bool
-    let forceExclude: Bool
-    let excludeByPrefix: Bool
-    let useScriptInputFiles: Bool
-    let benchmark: Bool
-    let reporter: String
-    let quiet: Bool
-    let enableAllRules: Bool
-    let autocorrect: Bool
-    let compilerLogPath: String
-    let compileCommands: String
-
-    // swiftlint:disable line_length
-    static func create(_ path: String) -> (_ configurationFiles: [String]) -> (_ strict: Bool) -> (_ lenient: Bool) -> (_ forceExclude: Bool) -> (_ excludeByPrefix: Bool) -> (_ useScriptInputFiles: Bool) -> (_ benchmark: Bool) -> (_ reporter: String) -> (_ quiet: Bool) -> (_ enableAllRules: Bool) -> (_ autocorrect: Bool) -> (_ compilerLogPath: String) -> (_ compileCommands: String) -> (_ paths: [String]) -> AnalyzeOptions {
-        return { configurationFiles in { strict in { lenient in { forceExclude in { excludeByPrefix in { useScriptInputFiles in { benchmark in { reporter in { quiet in { enableAllRules in { autocorrect in { compilerLogPath in { compileCommands in { paths in
-            let allPaths: [String]
-            if !path.isEmpty {
-                allPaths = [path]
-            } else {
-                allPaths = paths
-            }
-
-            return self.init(paths: allPaths, configurationFiles: configurationFiles, strict: strict, lenient: lenient, forceExclude: forceExclude, excludeByPrefix: excludeByPrefix, useScriptInputFiles: useScriptInputFiles, benchmark: benchmark, reporter: reporter, quiet: quiet, enableAllRules: enableAllRules, autocorrect: autocorrect, compilerLogPath: compilerLogPath, compileCommands: compileCommands)
-            // swiftlint:enable line_length
-        }}}}}}}}}}}}}}
-    }
-
-    static func evaluate(_ mode: CommandMode) -> Result<AnalyzeOptions, CommandantError<CommandantError<()>>> {
-        return create
-            <*> mode <| pathOption(action: "analyze")
-            <*> mode <| configOption
-            <*> mode <| Option(key: "strict", defaultValue: false,
-                               usage: "upgrades warnings to serious violations (errors)")
-            <*> mode <| Option(key: "lenient", defaultValue: false,
-                               usage: "downgrades serious violations to warnings, warning threshold is disabled")
-            <*> mode <| Option(key: "force-exclude", defaultValue: false,
-                               usage: "exclude files in config `excluded` even if their paths are explicitly specified")
-            <*> mode <| useAlternativeExcludingOption
-            <*> mode <| useScriptInputFilesOption
-            <*> mode <| Option(key: "benchmark", defaultValue: false,
-                               usage: "save benchmarks to benchmark_files.txt " +
-                                      "and benchmark_rules.txt")
-            <*> mode <| Option(key: "reporter", defaultValue: "",
-                               usage: "the reporter used to log errors and warnings")
-            <*> mode <| quietOption(action: "linting")
-            <*> mode <| Option(key: "enable-all-rules", defaultValue: false,
-                               usage: "run all rules, even opt-in and disabled ones, ignoring `only_rules`")
-            <*> mode <| Option(key: "autocorrect", defaultValue: false,
-                               usage: "correct violations whenever possible")
-            <*> mode <| Option(key: "compiler-log-path", defaultValue: "",
-                               usage: "the path of the full xcodebuild log to use when linting AnalyzerRules")
-            <*> mode <| Option(key: "compile-commands", defaultValue: "",
-                               usage: "the path of a compilation database to use when linting AnalyzerRules")
-            // This should go last to avoid eating other args
-            <*> mode <| pathsArgument(action: "analyze")
-    }
-}

Source/swiftlint/Commands/AutoCorrectCommand.swift

@@ -1,91 +0,0 @@
-import Commandant
-import SwiftLintFramework
-
-struct AutoCorrectCommand: CommandProtocol {
-    let verb = "autocorrect"
-    let function = "Automatically correct warnings and errors"
-
-    func run(_ options: AutoCorrectOptions) -> Result<(), CommandantError<()>> {
-        let configuration = Configuration(options: options)
-        let storage = RuleStorage()
-        let visitor = options.visitor(with: configuration, storage: storage)
-        return configuration.visitLintableFiles(with: visitor, storage: storage).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))!")
-            }
-            return .success(())
-        }
-    }
-}
-
-struct AutoCorrectOptions: OptionsProtocol {
-    let paths: [String]
-    let configurationFiles: [String]
-    let useScriptInputFiles: Bool
-    let quiet: Bool
-    let forceExclude: Bool
-    let excludeByPrefix: Bool
-    let format: Bool
-    let cachePath: String
-    let ignoreCache: Bool
-
-    // swiftlint:disable line_length
-    static func create(_ path: String) -> (_ configurationFiles: [String]) -> (_ useScriptInputFiles: Bool) -> (_ quiet: Bool) -> (_ forceExclude: Bool) ->
-    (_ excludeByPrefix: Bool) -> (_ format: Bool) -> (_ cachePath: String) -> (_ ignoreCache: Bool) -> (_ paths: [String]) -> AutoCorrectOptions {
-        return { configurationFiles in { useScriptInputFiles in { quiet in { forceExclude in { excludeByPrefix in { format in { cachePath in { ignoreCache in { paths in
-            let allPaths: [String]
-            if !path.isEmpty {
-                allPaths = [path]
-            } else {
-                allPaths = paths
-            }
-            return self.init(paths: allPaths, configurationFiles: configurationFiles, useScriptInputFiles: useScriptInputFiles, quiet: quiet, forceExclude: forceExclude,
-                             excludeByPrefix: excludeByPrefix, format: format, cachePath: cachePath, ignoreCache: ignoreCache)
-            // swiftlint:enable line_length
-            }}}}}}}}}
-    }
-
-    static func evaluate(_ mode: CommandMode) -> Result<AutoCorrectOptions, CommandantError<CommandantError<()>>> {
-        return create
-            <*> mode <| pathOption(action: "correct")
-            <*> mode <| configOption
-            <*> mode <| useScriptInputFilesOption
-            <*> mode <| quietOption(action: "correcting")
-            <*> mode <| Option(key: "force-exclude", defaultValue: false,
-                               usage: "exclude files in config `excluded` even if their paths are explicitly specified")
-            <*> mode <| useAlternativeExcludingOption
-            <*> mode <| Option(key: "format", defaultValue: false,
-                               usage: "should reformat the Swift files")
-            <*> mode <| Option(key: "cache-path", defaultValue: "",
-                               usage: "the directory of the cache used when correcting")
-            <*> mode <| Option(key: "no-cache", defaultValue: false,
-                               usage: "ignore cache when correcting")
-            // This should go last to avoid eating other args
-            <*> mode <| pathsArgument(action: "correct")
-    }
-
-    fileprivate func visitor(with configuration: Configuration, storage: RuleStorage) -> LintableFilesVisitor {
-        let cache = ignoreCache ? nil : LinterCache(configuration: configuration)
-        return LintableFilesVisitor(paths: paths, action: "Correcting", useSTDIN: false, quiet: quiet,
-                                    useScriptInputFiles: useScriptInputFiles, forceExclude: forceExclude,
-                                    useExcludingByPrefix: excludeByPrefix, cache: cache, parallel: true,
-                                    allowZeroLintableFiles: configuration.allowZeroLintableFiles) { linter in
-            if self.format {
-                switch configuration.indentation {
-                case .tabs:
-                    linter.format(useTabs: true, indentWidth: 4)
-                case .spaces(let count):
-                    linter.format(useTabs: false, indentWidth: count)
-                }
-            }
-            let corrections = linter.correct(using: storage)
-            if !corrections.isEmpty && !self.quiet {
-                let correctionLogs = corrections.map({ $0.consoleDescription })
-                queuedPrint(correctionLogs.joined(separator: "\n"))
-            }
-        }
-    }
-}

Source/swiftlint/Commands/Docs.swift

@@ -0,0 +1,29 @@
+import ArgumentParser
+import Foundation
+
+extension SwiftLint {
+    struct Docs: ParsableCommand {
+        static let configuration = CommandConfiguration(
+            abstract: "Open SwiftLint documentation website in the default web browser"
+        )
+
+        mutating func run() throws {
+            open(URL(string: "https://realm.github.io/SwiftLint")!)
+        }
+    }
+}
+
+private func open(_ url: URL) {
+    let process = Process()
+#if os(Linux)
+    process.executableURL = URL(fileURLWithPath: "/usr/bin/env")
+    let command = "xdg-open"
+    process.arguments = [command, url.absoluteString]
+    try? process.run()
+#else
+    process.launchPath = "/usr/bin/env"
+    let command = "open"
+    process.arguments = [command, url.absoluteString]
+    process.launch()
+#endif
+}

Source/swiftlint/Commands/GenerateDocs.swift

@@ -0,0 +1,17 @@
+import ArgumentParser
+import Foundation
+import SwiftLintFramework
+
+extension SwiftLint {
+    struct GenerateDocs: ParsableCommand {
+        static let configuration = CommandConfiguration(abstract: "Generates markdown documentation for all rules")
+
+        @Option(help: "The directory where the documentation should be saved")
+        var path = "rule_docs"
+
+        mutating func run() throws {
+            try RuleListDocumentation(primaryRuleList)
+                .write(to: URL(fileURLWithPath: path))
+        }
+    }
+}

Source/swiftlint/Commands/GenerateDocsCommand.swift

@@ -1,33 +0,0 @@
-import Commandant
-import Foundation
-import SwiftLintFramework
-
-struct GenerateDocsCommand: CommandProtocol {
-    let verb = "generate-docs"
-    let function = "Generates markdown documentation for all rules"
-
-    func run(_ options: GenerateDocsOptions) -> Result<(), CommandantError<()>> {
-        let docs = RuleListDocumentation(primaryRuleList)
-        do {
-            try docs.write(to: URL(fileURLWithPath: options.path))
-        } catch {
-            return .failure(.usageError(description: error.localizedDescription))
-        }
-
-        return .success(())
-    }
-}
-
-struct GenerateDocsOptions: OptionsProtocol {
-    let path: String
-
-    static func create(_ path: String) -> GenerateDocsOptions {
-        return self.init(path: path)
-    }
-
-    static func evaluate(_ mode: CommandMode) -> Result<GenerateDocsOptions, CommandantError<CommandantError<()>>> {
-        return create
-            <*> mode <| Option(key: "path", defaultValue: "rule_docs",
-                               usage: "the directory where the documentation should be saved. defaults to `rule_docs`.")
-    }
-}

Source/swiftlint/Commands/Lint.swift

@@ -0,0 +1,62 @@
+import ArgumentParser
+
+extension SwiftLint {
+    struct Lint: ParsableCommand {
+        static let configuration = CommandConfiguration(abstract: "Print lint warnings and errors")
+
+        @OptionGroup
+        var common: LintOrAnalyzeArguments
+        @Option(help: pathOptionDescription(for: .lint))
+        var path: String?
+        @Flag(help: "Lint standard input.")
+        var useSTDIN = false
+        @Flag(help: quietOptionDescription(for: .lint))
+        var quiet = false
+        @Option(help: "The directory of the cache used when linting.")
+        var cachePath: String?
+        @Flag(help: "Ignore cache when linting.")
+        var noCache = false
+        @Flag(help: "Run all rules, even opt-in and disabled ones, ignoring `only_rules`.")
+        var enableAllRules = false
+        @Argument(help: pathsArgumentDescription(for: .lint))
+        var paths = [String]()
+
+        mutating func run() throws {
+            let allPaths: [String]
+            if let path = path {
+                allPaths = [path]
+            } else if !paths.isEmpty {
+                allPaths = paths
+            } else {
+                allPaths = [""] // Lint files in current working directory if no paths were specified.
+            }
+            let options = LintOrAnalyzeOptions(
+                mode: .lint,
+                paths: allPaths,
+                useSTDIN: useSTDIN,
+                configurationFiles: common.config,
+                strict: common.leniency == .strict,
+                lenient: common.leniency == .lenient,
+                forceExclude: common.forceExclude,
+                useExcludingByPrefix: common.useAlternativeExcluding,
+                useScriptInputFiles: common.useScriptInputFiles,
+                benchmark: common.benchmark,
+                reporter: common.reporter,
+                quiet: quiet,
+                cachePath: cachePath,
+                ignoreCache: noCache,
+                enableAllRules: enableAllRules,
+                autocorrect: common.fix,
+                compilerLogPath: nil,
+                compileCommands: nil
+            )
+            let result = LintOrAnalyzeCommand.run(options)
+            switch result {
+            case .success:
+                return
+            case .failure(let error):
+                throw error
+            }
+        }
+    }
+}

Source/swiftlint/Commands/LintCommand.swift

@@ -1,72 +0,0 @@
-import Commandant
-
-struct LintCommand: CommandProtocol {
-    let verb = "lint"
-    let function = "Print lint warnings and errors (default command)"
-
-    func run(_ options: LintOptions) -> Result<(), CommandantError<()>> {
-        return LintOrAnalyzeCommand.run(LintOrAnalyzeOptions(options))
-    }
-}
-
-struct LintOptions: OptionsProtocol {
-    let paths: [String]
-    let useSTDIN: Bool
-    let configurationFiles: [String]
-    let strict: Bool
-    let lenient: Bool
-    let forceExclude: Bool
-    let excludeByPrefix: Bool
-    let useScriptInputFiles: Bool
-    let benchmark: Bool
-    let reporter: String
-    let quiet: Bool
-    let cachePath: String
-    let ignoreCache: Bool
-    let enableAllRules: Bool
-
-    // swiftlint:disable line_length
-    static func create(_ path: String) -> (_ useSTDIN: Bool) -> (_ configurationFiles: [String]) -> (_ strict: Bool) -> (_ lenient: Bool) -> (_ forceExclude: Bool) -> (_ excludeByPrefix: Bool) -> (_ useScriptInputFiles: Bool) -> (_ benchmark: Bool) -> (_ reporter: String) -> (_ quiet: Bool) -> (_ cachePath: String) -> (_ ignoreCache: Bool) -> (_ enableAllRules: Bool) -> (_ paths: [String]) -> LintOptions {
-        return { useSTDIN in { configurationFiles in { strict in { lenient in { forceExclude in { excludeByPrefix in { useScriptInputFiles in { benchmark in { reporter in { quiet in { cachePath in { ignoreCache in { enableAllRules in { paths in
-            let allPaths: [String]
-            if !path.isEmpty {
-                allPaths = [path]
-            } else {
-                allPaths = paths
-            }
-
-            return self.init(paths: allPaths, useSTDIN: useSTDIN, configurationFiles: configurationFiles, strict: strict, lenient: lenient, forceExclude: forceExclude, excludeByPrefix: excludeByPrefix, useScriptInputFiles: useScriptInputFiles, benchmark: benchmark, reporter: reporter, quiet: quiet, cachePath: cachePath, ignoreCache: ignoreCache, enableAllRules: enableAllRules)
-            // swiftlint:enable line_length
-        }}}}}}}}}}}}}}
-    }
-
-    static func evaluate(_ mode: CommandMode) -> Result<LintOptions, CommandantError<CommandantError<()>>> {
-        return create
-            <*> mode <| pathOption(action: "lint")
-            <*> mode <| Option(key: "use-stdin", defaultValue: false,
-                               usage: "lint standard input")
-            <*> mode <| configOption
-            <*> mode <| Option(key: "strict", defaultValue: false,
-                               usage: "upgrades warnings to serious violations (errors)")
-            <*> mode <| Option(key: "lenient", defaultValue: false,
-                               usage: "downgrades serious violations to warnings, warning threshold is disabled")
-            <*> mode <| Option(key: "force-exclude", defaultValue: false,
-                               usage: "exclude files in config `excluded` even if their paths are explicitly specified")
-            <*> mode <| useAlternativeExcludingOption
-            <*> mode <| useScriptInputFilesOption
-            <*> mode <| Option(key: "benchmark", defaultValue: false,
-                               usage: "save benchmarks to benchmark_files.txt " +
-                                      "and benchmark_rules.txt")
-            <*> mode <| Option(key: "reporter", defaultValue: "",
-                               usage: "the reporter used to log errors and warnings")
-            <*> mode <| quietOption(action: "linting")
-            <*> mode <| Option(key: "cache-path", defaultValue: "",
-                               usage: "the directory of the cache used when linting")
-            <*> mode <| Option(key: "no-cache", defaultValue: false,
-                               usage: "ignore cache when linting")
-            <*> mode <| Option(key: "enable-all-rules", defaultValue: false,
-                               usage: "run all rules, even opt-in and disabled ones, ignoring `only_rules`")
-            // This should go last to avoid eating other args
-            <*> mode <| pathsArgument(action: "lint")
-    }
-}

Source/swiftlint/Commands/Rules.swift

@@ -0,0 +1,164 @@
+import ArgumentParser
+#if canImport(Darwin)
+import Darwin
+#elseif canImport(Glibc)
+import Glibc
+#else
+#error("Unsupported platform")
+#endif
+import Foundation
+import SwiftLintFramework
+import SwiftyTextTable
+
+enum RuleEnablementOptions: String, EnumerableFlag {
+    case enabled, disabled
+
+    static func name(for value: RuleEnablementOptions) -> NameSpecification {
+        return .shortAndLong
+    }
+
+    static func help(for value: RuleEnablementOptions) -> ArgumentHelp? {
+        return "Only show \(value.rawValue) rules"
+    }
+}
+
+extension SwiftLint {
+    struct Rules: ParsableCommand {
+        static let configuration = CommandConfiguration(abstract: "Display the list of rules and their identifiers")
+
+        @Option(help: "The path to a SwiftLint configuration file")
+        var config: String?
+        @Flag(exclusivity: .exclusive)
+        var ruleEnablement: RuleEnablementOptions?
+        @Flag(name: .shortAndLong, help: "Only display correctable rules")
+        var correctable = false
+        @Flag(name: .shortAndLong, help: "Display full configuration details")
+        var verbose = false
+        @Argument(help: "The rule identifier to display description for")
+        var ruleID: String?
+
+        mutating func run() throws {
+            if let ruleID = ruleID {
+                guard let rule = primaryRuleList.list[ruleID] else {
+                    throw SwiftLintError.usageError(description: "No rule with identifier: \(ruleID)")
+                }
+
+                rule.description.printDescription()
+                return
+            }
+
+            let configuration = Configuration(configurationFiles: [config].compactMap({ $0 }))
+            let rules = ruleList(configuration: configuration)
+            let table = TextTable(ruleList: rules, configuration: configuration, verbose: verbose)
+            print(table.render())
+        }
+
+        private func ruleList(configuration: Configuration) -> RuleList {
+            guard ruleEnablement != nil || correctable else {
+                return primaryRuleList
+            }
+
+            let filtered: [Rule.Type] = primaryRuleList.list.compactMap { ruleID, ruleType in
+                let configuredRule = configuration.rules.first { rule in
+                    return type(of: rule).description.identifier == ruleID
+                }
+
+                if ruleEnablement == .enabled && configuredRule == nil {
+                    return nil
+                } else if ruleEnablement == .disabled && configuredRule != nil {
+                    return nil
+                } else if correctable && !(configuredRule is CorrectableRule) {
+                    return nil
+                }
+
+                return ruleType
+            }
+
+            return RuleList(rules: filtered)
+        }
+    }
+}
+
+private extension RuleDescription {
+    func printDescription() {
+        print("\(consoleDescription)")
+
+        guard !triggeringExamples.isEmpty else { return }
+
+        func indent(_ string: String) -> String {
+            return string.components(separatedBy: "\n")
+                .map { "    \($0)" }
+                .joined(separator: "\n")
+        }
+        print("\nTriggering Examples (violation is marked with '↓'):")
+        for (index, example) in triggeringExamples.enumerated() {
+            print("\nExample #\(index + 1)\n\n\(indent(example.code))")
+        }
+    }
+}
+
+// MARK: - SwiftyTextTable
+
+private extension TextTable {
+    init(ruleList: RuleList, configuration: Configuration, verbose: Bool) {
+        let columns = [
+            TextTableColumn(header: "identifier"),
+            TextTableColumn(header: "opt-in"),
+            TextTableColumn(header: "correctable"),
+            TextTableColumn(header: "enabled in your config"),
+            TextTableColumn(header: "kind"),
+            TextTableColumn(header: "analyzer"),
+            TextTableColumn(header: "configuration")
+        ]
+        self.init(columns: columns)
+        let sortedRules = ruleList.list.sorted { $0.0 < $1.0 }
+        func truncate(_ string: String) -> String {
+            let stringWithNoNewlines = string.replacingOccurrences(of: "\n", with: "\\n")
+            let minWidth = "configuration".count - "...".count
+            let configurationStartColumn = 124
+            let maxWidth = verbose ? Int.max : Terminal.currentWidth()
+            let truncatedEndIndex = stringWithNoNewlines.index(
+                stringWithNoNewlines.startIndex,
+                offsetBy: max(minWidth, maxWidth - configurationStartColumn),
+                limitedBy: stringWithNoNewlines.endIndex
+            )
+            if let truncatedEndIndex = truncatedEndIndex {
+                return stringWithNoNewlines[..<truncatedEndIndex] + "..."
+            }
+            return stringWithNoNewlines
+        }
+        for (ruleID, ruleType) in sortedRules {
+            let rule = ruleType.init()
+            let configuredRule = configuration.rules.first { rule in
+                guard type(of: rule).description.identifier == ruleID else {
+                    return false
+                }
+                guard let customRules = rule as? CustomRules else {
+                    return true
+                }
+                return !customRules.configuration.customRuleConfigurations.isEmpty
+            }
+            addRow(values: [
+                ruleID,
+                (rule is OptInRule) ? "yes" : "no",
+                (rule is CorrectableRule) ? "yes" : "no",
+                configuredRule != nil ? "yes" : "no",
+                ruleType.description.kind.rawValue,
+                (rule is AnalyzerRule) ? "yes" : "no",
+                truncate((configuredRule ?? rule).configurationDescription)
+            ])
+        }
+    }
+}
+
+private struct Terminal {
+    static func currentWidth() -> Int {
+        var size = winsize()
+#if os(Linux)
+        _ = ioctl(CInt(STDOUT_FILENO), UInt(TIOCGWINSZ), &size)
+#else
+        _ = ioctl(STDOUT_FILENO, TIOCGWINSZ, &size)
+#endif
+        return Int(size.ws_col)
+    }
+}

Source/swiftlint/Commands/RulesCommand.swift

@@ -1,182 +0,0 @@
-import Commandant
-#if canImport(Darwin)
-import Darwin
-#elseif canImport(Glibc)
-import Glibc
-#else
-#error("Unsupported platform")
-#endif
-import SwiftLintFramework
-import SwiftyTextTable
-
-private func print(ruleDescription desc: RuleDescription) {
-    print("\(desc.consoleDescription)")
-
-    if !desc.triggeringExamples.isEmpty {
-        func indent(_ string: String) -> String {
-            return string.components(separatedBy: "\n")
-                .map { "    \($0)" }
-                .joined(separator: "\n")
-        }
-        print("\nTriggering Examples (violation is marked with '↓'):")
-        for (index, example) in desc.triggeringExamples.enumerated() {
-            print("\nExample #\(index + 1)\n\n\(indent(example.code))")
-        }
-    }
-}
-
-struct RulesCommand: CommandProtocol {
-    let verb = "rules"
-    let function = "Display the list of rules and their identifiers"
-
-    func run(_ options: RulesOptions) -> Result<(), CommandantError<()>> {
-        if let ruleID = options.ruleID {
-            guard let rule = primaryRuleList.list[ruleID] else {
-                return .failure(.usageError(description: "No rule with identifier: \(ruleID)"))
-            }
-
-            print(ruleDescription: rule.description)
-            return .success(())
-        }
-
-        if options.onlyDisabledRules && options.onlyEnabledRules {
-            return .failure(.usageError(description: "You can't use --disabled and --enabled at the same time."))
-        }
-
-        let configuration = Configuration(options: options)
-        let rules = ruleList(for: options, configuration: configuration)
-
-        print(TextTable(ruleList: rules, configuration: configuration, verbose: options.verbose).render())
-        return .success(())
-    }
-
-    private func ruleList(for options: RulesOptions, configuration: Configuration) -> RuleList {
-        guard options.onlyEnabledRules || options.onlyDisabledRules || options.onlyCorrectableRules else {
-            return primaryRuleList
-        }
-
-        let filtered: [Rule.Type] = primaryRuleList.list.compactMap { ruleID, ruleType in
-            let configuredRule = configuration.rules.first { rule in
-                return type(of: rule).description.identifier == ruleID
-            }
-
-            if options.onlyEnabledRules && configuredRule == nil {
-                return nil
-            } else if options.onlyDisabledRules && configuredRule != nil {
-                return nil
-            } else if options.onlyCorrectableRules && !(configuredRule is CorrectableRule) {
-                return nil
-            }
-
-            return ruleType
-        }
-
-        return RuleList(rules: filtered)
-    }
-}
-
-struct RulesOptions: OptionsProtocol {
-    fileprivate let ruleID: String?
-    let configurationFiles: [String]
-    fileprivate let onlyEnabledRules: Bool
-    fileprivate let onlyDisabledRules: Bool
-    fileprivate let onlyCorrectableRules: Bool
-    fileprivate let verbose: Bool
-
-    // swiftlint:disable line_length
-    static func create(_ configurationFiles: [String]) -> (_ ruleID: String) -> (_ onlyEnabledRules: Bool) -> (_ onlyDisabledRules: Bool) -> (_ onlyCorrectableRules: Bool) -> (_ verbose: Bool) -> RulesOptions {
-        return { ruleID in { onlyEnabledRules in { onlyDisabledRules in { onlyCorrectableRules in { verbose in
-            self.init(ruleID: (ruleID.isEmpty ? nil : ruleID),
-                      configurationFiles: configurationFiles,
-                      onlyEnabledRules: onlyEnabledRules,
-                      onlyDisabledRules: onlyDisabledRules,
-                      onlyCorrectableRules: onlyCorrectableRules,
-                      verbose: verbose)
-        }}}}}
-    }
-
-    static func evaluate(_ mode: CommandMode) -> Result<RulesOptions, CommandantError<CommandantError<()>>> {
-        return create
-            <*> mode <| configOption
-            <*> mode <| Argument(defaultValue: "",
-                                 usage: "the rule identifier to display description for")
-            <*> mode <| Switch(flag: "e",
-                               key: "enabled",
-                               usage: "only display enabled rules")
-            <*> mode <| Switch(flag: "d",
-                               key: "disabled",
-                               usage: "only display disabled rules")
-            <*> mode <| Switch(flag: "c",
-                               key: "correctable",
-                               usage: "only display correctable rules")
-            <*> mode <| Switch(flag: "v",
-                               key: "verbose",
-                               usage: "display full configuration detail")
-    }
-}
-
-// MARK: - SwiftyTextTable
-
-extension TextTable {
-    init(ruleList: RuleList, configuration: Configuration, verbose: Bool) {
-        let columns = [
-            TextTableColumn(header: "identifier"),
-            TextTableColumn(header: "opt-in"),
-            TextTableColumn(header: "correctable"),
-            TextTableColumn(header: "enabled in your config"),
-            TextTableColumn(header: "kind"),
-            TextTableColumn(header: "analyzer"),
-            TextTableColumn(header: "configuration")
-        ]
-        self.init(columns: columns)
-        let sortedRules = ruleList.list.sorted { $0.0 < $1.0 }
-        func truncate(_ string: String) -> String {
-            let stringWithNoNewlines = string.replacingOccurrences(of: "\n", with: "\\n")
-            let minWidth = "configuration".count - "...".count
-            let configurationStartColumn = 124
-            let maxWidth = verbose ? Int.max : Terminal.currentWidth()
-            let truncatedEndIndex = stringWithNoNewlines.index(
-                stringWithNoNewlines.startIndex,
-                offsetBy: max(minWidth, maxWidth - configurationStartColumn),
-                limitedBy: stringWithNoNewlines.endIndex
-            )
-            if let truncatedEndIndex = truncatedEndIndex {
-                return stringWithNoNewlines[..<truncatedEndIndex] + "..."
-            }
-            return stringWithNoNewlines
-        }
-        for (ruleID, ruleType) in sortedRules {
-            let rule = ruleType.init()
-            let configuredRule = configuration.rules.first { rule in
-                guard type(of: rule).description.identifier == ruleID else {
-                    return false
-                }
-                guard let customRules = rule as? CustomRules else {
-                    return true
-                }
-                return !customRules.configuration.customRuleConfigurations.isEmpty
-            }
-            addRow(values: [
-                ruleID,
-                (rule is OptInRule) ? "yes" : "no",
-                (rule is CorrectableRule) ? "yes" : "no",
-                configuredRule != nil ? "yes" : "no",
-                ruleType.description.kind.rawValue,
-                (rule is AnalyzerRule) ? "yes" : "no",
-                truncate((configuredRule ?? rule).configurationDescription)
-            ])
-        }
-    }
-}
-
-struct Terminal {
-    static func currentWidth() -> Int {
-        var size = winsize()
-#if os(Linux)
-        _ = ioctl(CInt(STDOUT_FILENO), UInt(TIOCGWINSZ), &size)
-#else
-        _ = ioctl(STDOUT_FILENO, TIOCGWINSZ, &size)
-#endif
-        return Int(size.ws_col)
-    }
-}

Source/swiftlint/Commands/ShowDocsCommand.swift

@@ -1,30 +0,0 @@
-import Commandant
-import Foundation
-
-struct ShowDocsCommand: CommandProtocol {
-    let verb = "docs"
-    let function = "Open SwiftLint Docs on web browser"
-
-    func run(_ options: NoOptions<CommandantError<()>>) -> Result<(), CommandantError<()>> {
-        let url = URL(string: "https://realm.github.io/SwiftLint")!
-        open(url)
-        return .success(())
-    }
-}
-
-private extension ShowDocsCommand {
-    func open(_ url: URL) {
-        let process = Process()
-#if os(Linux)
-        process.executableURL = URL(fileURLWithPath: "/usr/bin/env")
-        let command = "xdg-open"
-        process.arguments = [command, url.absoluteString]
-        try? process.run()
-#else
-        process.launchPath = "/usr/bin/env"
-        let command = "open"
-        process.arguments = [command, url.absoluteString]
-        process.launch()
-#endif
-    }
-}

Source/swiftlint/Commands/SwiftLint.swift

@@ -0,0 +1,38 @@
+import ArgumentParser
+import SwiftLintFramework
+
+struct SwiftLint: ParsableCommand {
+    static var configuration = CommandConfiguration(
+        commandName: "swiftlint",
+        abstract: "A tool to enforce Swift style and conventions.",
+        version: Version.value,
+        subcommands: [
+            Analyze.self,
+            Docs.self,
+            GenerateDocs.self,
+            Lint.self,
+            Rules.self,
+            Version.self
+        ],
+        defaultSubcommand: Lint.self
+    )
+
+    // Temporary convenience to help migrate users to the new command.
+    static func mainHandlingDeprecatedCommands(_ arguments: [String]? = nil) {
+        let argumentsToCheck = arguments ?? Array(CommandLine.arguments.dropFirst())
+        guard argumentsToCheck.first == "autocorrect" else {
+            main(arguments)
+            return
+        }
+
+        queuedPrintError(
+            """
+            The `swiftlint autocorrect` command is no longer available.
+            Please use `swiftlint --fix` instead.
+            """
+        )
+        var newArguments = argumentsToCheck
+        newArguments[0] = "--fix"
+        main(newArguments)
+    }
+}

Source/swiftlint/Commands/Version.swift

@@ -0,0 +1,14 @@
+import ArgumentParser
+import SwiftLintFramework
+
+extension SwiftLint {
+    struct Version: ParsableCommand {
+        static let configuration = CommandConfiguration(abstract: "Display the current version of SwiftLint")
+
+        static var value: String { SwiftLintFramework.Version.current.value }
+
+        mutating func run() throws {
+            print(Self.value)
+        }
+    }
+}

Source/swiftlint/Commands/VersionCommand.swift

@@ -1,12 +0,0 @@
-import Commandant
-import SwiftLintFramework
-
-struct VersionCommand: CommandProtocol {
-    let verb = "version"
-    let function = "Display the current version of SwiftLint"
-
-    func run(_ options: NoOptions<CommandantError<()>>) -> Result<(), CommandantError<()>> {
-        print(Version.current.value)
-        return .success(())
-    }
-}

Source/swiftlint/Extensions/Configuration+CommandLine.swift

@@ -1,4 +1,3 @@
-import Commandant
 import Dispatch
 import Foundation
 import SourceKittenFramework
@@ -6,8 +5,8 @@ import SwiftLintFramework
 
 private let indexIncrementerQueue = DispatchQueue(label: "io.realm.swiftlint.indexIncrementer")
 
-private func scriptInputFiles() -> Result<[SwiftLintFile], CommandantError<()>> {
-    func getEnvironmentVariable(_ variable: String) -> Result<String, CommandantError<()>> {
+private func scriptInputFiles() -> Result<[SwiftLintFile], SwiftLintError> {
+    func getEnvironmentVariable(_ variable: String) -> Result<String, SwiftLintError> {
         let environment = ProcessInfo.processInfo.environment
         if let value = environment[variable] {
             return .success(value)
@@ -15,7 +14,7 @@ private func scriptInputFiles() -> Result<[SwiftLintFile], CommandantError<()>>
         return .failure(.usageError(description: "Environment variable not set: \(variable)"))
     }
 
-    let count: Result<Int, CommandantError<()>> = {
+    let count: Result<Int, SwiftLintError> = {
         let inputFileKey = "SCRIPT_INPUT_FILE_COUNT"
         guard let countString = ProcessInfo.processInfo.environment[inputFileKey] else {
             return .failure(.usageError(description: "\(inputFileKey) variable not set"))
@@ -48,7 +47,7 @@ private func autoreleasepool<T>(block: () -> T) -> T { return block() }
 
 extension Configuration {
     func visitLintableFiles(with visitor: LintableFilesVisitor, storage: RuleStorage)
-        -> Result<[SwiftLintFile], CommandantError<()>> {
+        -> Result<[SwiftLintFile], SwiftLintError> {
             return getFiles(with: visitor)
                 .flatMap { groupFiles($0, visitor: visitor) }
                 .map { linters(for: $0, visitor: visitor) }
@@ -59,7 +58,7 @@ extension Configuration {
 
     private func groupFiles(_ files: [SwiftLintFile],
                             visitor: LintableFilesVisitor)
-        -> Result<[Configuration: [SwiftLintFile]], CommandantError<()>> {
+        -> Result<[Configuration: [SwiftLintFile]], SwiftLintError> {
         if files.isEmpty && !visitor.allowZeroLintableFiles {
             let errorMessage = "No lintable files found at paths: '\(visitor.paths.joined(separator: ", "))'"
             return .failure(.usageError(description: errorMessage))
@@ -188,7 +187,7 @@ extension Configuration {
         return visitor.parallel ? linters.parallelMap(transform: visit) : linters.map(visit)
     }
 
-    fileprivate func getFiles(with visitor: LintableFilesVisitor) -> Result<[SwiftLintFile], CommandantError<()>> {
+    fileprivate func getFiles(with visitor: LintableFilesVisitor) -> Result<[SwiftLintFile], SwiftLintError> {
         if visitor.useSTDIN {
             let stdinData = FileHandle.standardInput.readDataToEndOfFile()
             if let stdinString = String(data: stdinData, encoding: .utf8) {
@@ -225,20 +224,9 @@ extension Configuration {
         })
     }
 
-    // MARK: LintOrAnalyze Command
-
-    init(options: LintOrAnalyzeOptions) {
-        let cachePath = options.cachePath.isEmpty ? nil : options.cachePath
-        self.init(
-            configurationFiles: options.configurationFiles,
-            enableAllRules: options.enableAllRules,
-            cachePath: cachePath
-        )
-    }
-
     func visitLintableFiles(options: LintOrAnalyzeOptions, cache: LinterCache? = nil, storage: RuleStorage,
                             visitorBlock: @escaping (CollectedLinter) -> Void)
-        -> Result<[SwiftLintFile], CommandantError<()>> {
+        -> Result<[SwiftLintFile], SwiftLintError> {
             return LintableFilesVisitor.create(options,
                                                cache: cache,
                                                allowZeroLintableFiles: allowZeroLintableFiles,
@@ -247,20 +235,13 @@ extension Configuration {
         })
     }
 
-    // MARK: AutoCorrect Command
+    // MARK: LintOrAnalyze Command
 
-    init(options: AutoCorrectOptions) {
-        let cachePath = options.cachePath.isEmpty ? nil : options.cachePath
+    init(options: LintOrAnalyzeOptions) {
         self.init(
             configurationFiles: options.configurationFiles,
-            cachePath: cachePath
-        )
-    }
-
-    // MARK: Rules command
-    init(options: RulesOptions) {
-        self.init(
-            configurationFiles: options.configurationFiles
+            enableAllRules: options.enableAllRules,
+            cachePath: options.cachePath
         )
     }
 }

Source/swiftlint/Extensions/Reporter+CommandLine.swift

@@ -11,7 +11,6 @@ extension Reporter {
     }
 }
 
-func reporterFrom(optionsReporter: String, configuration: Configuration) -> Reporter.Type {
-    let string = optionsReporter.isEmpty ? configuration.reporter : optionsReporter
-    return reporterFrom(identifier: string)
+func reporterFrom(optionsReporter: String?, configuration: Configuration) -> Reporter.Type {
+    return reporterFrom(identifier: optionsReporter ?? configuration.reporter)
 }

Source/swiftlint/Helpers/CommonOptions.swift

@@ -1,34 +0,0 @@
-import Commandant
-
-func pathOption(action: String) -> Option<String> {
-    return Option(key: "path",
-                  defaultValue: "",
-                  usage: "the path to the file or directory to \(action)")
-}
-
-func pathsArgument(action: String) -> Argument<[String]> {
-    return Argument(defaultValue: [""],
-                    usage: "list of paths to the files or directories to \(action)")
-}
-
-let configOption = Option(key: "config",
-                          defaultValue: [String](),
-                          usage: "the path to one or more SwiftLint configuration files, "
-                            + "evaluated as a parent-child hierarchy")
-
-let useScriptInputFilesOption = Option(key: "use-script-input-files",
-                                       defaultValue: false,
-                                       usage: "read SCRIPT_INPUT_FILE* environment variables " +
-                                            "as files")
-
-let useAlternativeExcludingOption = Option(key: "use-alternative-excluding",
-                                           defaultValue: false,
-                                           usage: "alternative exclude paths algorithm for `excluded`." +
-                                                  "may speed up excluding for some cases")
-
-func quietOption(action: String) -> Option<Bool> {
-    return Option(key: "quiet",
-                  defaultValue: false,
-                  usage: "don't print status logs like '\(action.capitalized) <file>' & " +
-                    "'Done \(action)'")
-}

Source/swiftlint/Helpers/LintOrAnalyzeArguments.swift

@@ -0,0 +1,52 @@
+import ArgumentParser
+
+enum LeniencyOptions: String, EnumerableFlag {
+    case strict, lenient
+
+    static func help(for value: LeniencyOptions) -> ArgumentHelp? {
+        switch value {
+        case .strict:
+            return "Upgrades warnings to serious violations (errors)."
+        case .lenient:
+            return "Downgrades serious violations to warnings, warning threshold is disabled."
+        }
+    }
+}
+
+// MARK: - Common Arguments
+
+struct LintOrAnalyzeArguments: ParsableArguments {
+    @Option(help: "The path to one or more SwiftLint configuration files, evaluated as a parent-child hierarchy.")
+    var config = [String]()
+    @Flag(name: [.long, .customLong("autocorrect")], help: "Correct violations whenever possible.")
+    var fix = false
+    @Flag(help: "Use an alternative algorithm to exclude paths for `excluded`, which may be faster in some cases.")
+    var useAlternativeExcluding = false
+    @Flag(help: "Read SCRIPT_INPUT_FILE* environment variables as files.")
+    var useScriptInputFiles = false
+    @Flag(exclusivity: .exclusive)
+    var leniency: LeniencyOptions?
+    @Flag(help: "Exclude files in config `excluded` even if their paths are explicitly specified.")
+    var forceExclude = false
+    @Flag(help: "Save benchmarks to `benchmark_files.txt` and `benchmark_rules.txt`.")
+    var benchmark = false
+    @Option(help: "The reporter used to log errors and warnings.")
+    var reporter: String?
+}
+
+// MARK: - Common Argument Help
+
+// It'd be great to be able to parameterize an `@OptionGroup` so we could move these options into
+// `LintOrAnalyzeArguments`.
+
+func pathOptionDescription(for mode: LintOrAnalyzeMode) -> ArgumentHelp {
+    "The path to the file or directory to \(mode.imperative)."
+}
+
+func pathsArgumentDescription(for mode: LintOrAnalyzeMode) -> ArgumentHelp {
+    "List of paths to the files or directories to \(mode.imperative)."
+}
+
+func quietOptionDescription(for mode: LintOrAnalyzeMode) -> ArgumentHelp {
+    "Don't print status logs like '\(mode.verb.capitalized) <file>' & 'Done \(mode.verb)'."
+}

Source/swiftlint/Helpers/LintOrAnalyzeCommand.swift

@@ -1,4 +1,3 @@
-import Commandant
 import Dispatch
 import Foundation
 import SwiftLintFramework
@@ -6,6 +5,15 @@ import SwiftLintFramework
 enum LintOrAnalyzeMode {
     case lint, analyze
 
+    var imperative: String {
+        switch self {
+        case .lint:
+            return "lint"
+        case .analyze:
+            return "analyze"
+        }
+    }
+
     var verb: String {
         switch self {
         case .lint:
@@ -17,7 +25,11 @@ enum LintOrAnalyzeMode {
 }
 
 struct LintOrAnalyzeCommand {
-    static func run(_ options: LintOrAnalyzeOptions) -> Result<(), CommandantError<()>> {
+    static func run(_ options: LintOrAnalyzeOptions) -> Result<(), SwiftLintError> {
+        return options.autocorrect ? autocorrect(options) : lintOrAnalyze(options)
+    }
+
+    private static func lintOrAnalyze(_ options: LintOrAnalyzeOptions) -> Result<(), SwiftLintError> {
         var fileBenchmark = Benchmark(name: "files")
         var ruleBenchmark = Benchmark(name: "rules")
         var violations = [StyleViolation]()
@@ -125,6 +137,26 @@ struct LintOrAnalyzeCommand {
             queuedFatalError("Invalid command line options: 'lenient' and 'strict' are mutually exclusive.")
         }
     }
+
+    private static func autocorrect(_ options: LintOrAnalyzeOptions) -> Result<(), SwiftLintError> {
+        let storage = RuleStorage()
+        let configuration = Configuration(options: options)
+        return configuration.visitLintableFiles(options: options, cache: nil, storage: storage) { linter in
+            let corrections = linter.correct(using: storage)
+            if !corrections.isEmpty && !options.quiet {
+                let correctionLogs = corrections.map({ $0.consoleDescription })
+                queuedPrint(correctionLogs.joined(separator: "\n"))
+            }
+        }.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))!")
+            }
+            return .success(())
+        }
+    }
 }
 
 struct LintOrAnalyzeOptions {
@@ -138,56 +170,14 @@ struct LintOrAnalyzeOptions {
     let useExcludingByPrefix: Bool
     let useScriptInputFiles: Bool
     let benchmark: Bool
-    let reporter: String
+    let reporter: String?
     let quiet: Bool
-    let cachePath: String
+    let cachePath: String?
     let ignoreCache: Bool
     let enableAllRules: Bool
     let autocorrect: Bool
-    let compilerLogPath: String
-    let compileCommands: String
-
-    init(_ options: LintOptions) {
-        mode = .lint
-        paths = options.paths
-        useSTDIN = options.useSTDIN
-        configurationFiles = options.configurationFiles
-        strict = options.strict
-        lenient = options.lenient
-        forceExclude = options.forceExclude
-        useExcludingByPrefix = options.excludeByPrefix
-        useScriptInputFiles = options.useScriptInputFiles
-        benchmark = options.benchmark
-        reporter = options.reporter
-        quiet = options.quiet
-        cachePath = options.cachePath
-        ignoreCache = options.ignoreCache
-        enableAllRules = options.enableAllRules
-        autocorrect = false
-        compilerLogPath = ""
-        compileCommands = ""
-    }
-
-    init(_ options: AnalyzeOptions) {
-        mode = .analyze
-        paths = options.paths
-        useSTDIN = false
-        configurationFiles = options.configurationFiles
-        strict = options.strict
-        lenient = options.lenient
-        forceExclude = options.forceExclude
-        useExcludingByPrefix = options.excludeByPrefix
-        useScriptInputFiles = options.useScriptInputFiles
-        benchmark = options.benchmark
-        reporter = options.reporter
-        quiet = options.quiet
-        cachePath = ""
-        ignoreCache = true
-        enableAllRules = options.enableAllRules
-        autocorrect = options.autocorrect
-        compilerLogPath = options.compilerLogPath
-        compileCommands = options.compileCommands
-    }
+    let compilerLogPath: String?
+    let compileCommands: String?
 
     var verb: String {
         if autocorrect {

Source/swiftlint/Helpers/LintableFilesVisitor.swift

@@ -1,4 +1,3 @@
-import Commandant
 import Foundation
 import SourceKittenFramework
 import SwiftLintFramework
@@ -96,7 +95,7 @@ struct LintableFilesVisitor {
                        cache: LinterCache?,
                        allowZeroLintableFiles: Bool,
                        block: @escaping (CollectedLinter) -> Void)
-        -> Result<LintableFilesVisitor, CommandantError<()>> {
+        -> Result<LintableFilesVisitor, SwiftLintError> {
         let compilerInvocations: CompilerInvocations?
         if options.mode == .lint {
             compilerInvocations = nil
@@ -141,9 +140,8 @@ struct LintableFilesVisitor {
     }
 
     private static func loadCompilerInvocations(_ options: LintOrAnalyzeOptions)
-        -> Result<CompilerInvocations, CommandantError<()>> {
-        if !options.compilerLogPath.isEmpty {
-            let path = options.compilerLogPath
+        -> Result<CompilerInvocations, SwiftLintError> {
+        if let path = options.compilerLogPath {
             guard let compilerInvocations = self.loadLogCompilerInvocations(path) else {
                 return .failure(
                     .usageError(description: "Could not read compiler log at path: '\(path)'")
@@ -151,17 +149,14 @@ struct LintableFilesVisitor {
             }
 
             return .success(.buildLog(compilerInvocations: compilerInvocations))
-        } else if !options.compileCommands.isEmpty {
-            let path = options.compileCommands
+        } else if let path = options.compileCommands {
             switch self.loadCompileCommands(path) {
             case .success(let compileCommands):
                 return .success(.compilationDatabase(compileCommands: compileCommands))
             case .failure(let error):
-                return .failure(
-                    .usageError(
-                        description: "Could not read compilation database at path: '\(path)' \(error.description)"
-                    )
-                )
+                return .failure(.usageError(
+                    description: "Could not read compilation database at path: '\(path)' \(error.localizedDescription)"
+                ))
             }
         }
 
@@ -220,14 +215,14 @@ struct LintableFilesVisitor {
     }
 }
 
-private enum CompileCommandsLoadError: Error {
+private enum CompileCommandsLoadError: LocalizedError {
     case nonExistentFile(String)
     case malformedCommands(String)
     case malformedFile(String, Int)
     case malformedArguments(String, Int)
     case missingFileInArguments(String, Int, [String])
 
-    var description: String {
+    var errorDescription: String? {
         switch self {
         case let .nonExistentFile(path):
             return "Could not read compile commands file at '\(path)'"

Source/swiftlint/Helpers/SwiftLintError.swift

@@ -0,0 +1,12 @@
+import Foundation
+
+enum SwiftLintError: LocalizedError {
+    case usageError(description: String)
+
+    var errorDescription: String? {
+        switch self {
+        case .usageError(let description):
+            return description
+        }
+    }
+}

Source/swiftlint/main.swift

@@ -1,21 +1,15 @@
-import Commandant
 import Dispatch
-import SwiftLintFramework
+#if canImport(Darwin)
+import Darwin
+#elseif canImport(Glibc)
+import Glibc
+#else
+#error("Unsupported platform")
+#endif
 
 DispatchQueue.global().async {
-    let registry = CommandRegistry<CommandantError<()>>()
-    registry.register(LintCommand())
-    registry.register(AutoCorrectCommand())
-    registry.register(AnalyzeCommand())
-    registry.register(VersionCommand())
-    registry.register(RulesCommand())
-    registry.register(GenerateDocsCommand())
-    registry.register(ShowDocsCommand())
-    registry.register(HelpCommand(registry: registry))
-
-    registry.main(defaultVerb: LintCommand().verb) { error in
-        queuedPrintError(String(describing: error))
-    }
+    SwiftLint.mainHandlingDeprecatedCommands()
+    exit(EXIT_SUCCESS)
 }
 
 dispatchMain()

SwiftLintFramework.podspec

@@ -10,6 +10,6 @@ Pod::Spec.new do |s|
   s.source_files        = 'Source/SwiftLintFramework/**/*.swift'
   s.swift_versions      = ['5.2', '5.3']
   s.pod_target_xcconfig = { 'APPLICATION_EXTENSION_API_ONLY' => 'YES' }
-  s.dependency            'SourceKittenFramework', '~> 0.30.1'
+  s.dependency            'SourceKittenFramework', '~> 0.31.0'
   s.dependency            'Yams', '~> 4.0.2'
 end