Record start positions of commands

CHANGELOG.md

@@ -18,6 +18,7 @@
 
 * Fix issue referencing the Tests package from another Bazel workspace.  
   [jszumski](https://github.com/jszumski)
+
 * Fix crash when a disable command is preceded by a unicode character.  
   [SimplyDanny](https://github.com/SimplyDanny)
   [#5945](https://github.com/realm/SwiftLint/issues/5945)

Source/SwiftLintBuiltInRules/Rules/Lint/InvalidSwiftLintCommandRule.swift

@@ -15,7 +15,8 @@ struct InvalidSwiftLintCommandRule: Rule, SourceKitFreeRule {
             Example("// swiftlint:disable:previous unused_import"),
             Example("// swiftlint:disable:this unused_import"),
             Example("//swiftlint:disable:this unused_import"),
-            Example("_ = \"🤵🏼‍♀️\" // swiftlint:disable:this unused_import"),
+            Example("_ = \"🤵🏼‍♀️\" // swiftlint:disable:this unused_import", excludeFromDocumentation: true),
+            Example("_ = \"🤵🏼‍♀️ 🤵🏼‍♀️\" // swiftlint:disable:this unused_import", excludeFromDocumentation: true),
         ],
         triggeringExamples: [
             Example("// ↓swiftlint:"),
@@ -33,6 +34,7 @@ struct InvalidSwiftLintCommandRule: Rule, SourceKitFreeRule {
             Example("// ↓swiftlint:enable: "),
             Example("// ↓swiftlint:disable: unused_import"),
             Example("// s↓swiftlint:disable unused_import"),
+            Example("// 🤵🏼‍♀️swiftlint:disable unused_import", excludeFromDocumentation: true),
         ].skipWrappingInCommentTests()
     )
 
@@ -42,15 +44,13 @@ struct InvalidSwiftLintCommandRule: Rule, SourceKitFreeRule {
 
     private func badPrefixViolations(in file: SwiftLintFile) -> [StyleViolation] {
         (file.commands + file.invalidCommands).compactMap { command in
-            if let precedingCharacter = command.precedingCharacter(in: file)?.unicodeScalars.first,
-               !CharacterSet.whitespaces.union(CharacterSet(charactersIn: "/")).contains(precedingCharacter) {
-                return styleViolation(
+            command.isPrecededByInvalidCharacter(in: file)
+                ? styleViolation(
                     for: command,
                     in: file,
                     reason: "swiftlint command should be preceded by whitespace or a comment character"
                 )
-            }
-            return nil
+                : nil
         }
     }
 
@@ -61,53 +61,26 @@ struct InvalidSwiftLintCommandRule: Rule, SourceKitFreeRule {
     }
 
     private func styleViolation(for command: Command, in file: SwiftLintFile, reason: String) -> StyleViolation {
-        let character = command.startingCharacterPosition(in: file)
-        let characterOffset = character.flatMap {
-            if let line = command.lineOfCommand(in: file) {
-                return line.distance(from: line.startIndex, to: $0)
-            }
-            return nil
-        }
-        return StyleViolation(
+        StyleViolation(
             ruleDescription: Self.description,
             severity: configuration.severity,
-            location: Location(file: file.path, line: command.line, character: characterOffset),
+            location: Location(file: file.path, line: command.line, character: command.character),
             reason: reason
         )
     }
 }
 
 private extension Command {
-    func lineOfCommand(in file: SwiftLintFile) -> String? {
-        guard line > 0, line <= file.lines.count else {
-            return nil
-        }
-        return file.lines[line - 1].content
-    }
-
-    func startingCharacterPosition(in file: SwiftLintFile) -> String.Index? {
-        guard let line = lineOfCommand(in: file), line.isNotEmpty else {
-            return nil
-        }
-        if let commandIndex = line.range(of: "swiftlint:")?.lowerBound {
-            let distance = line.distance(from: line.startIndex, to: commandIndex)
-            return line.index(line.startIndex, offsetBy: distance + 1)
-        }
-        if let character {
-            return line.index(line.startIndex, offsetBy: character)
-        }
-        return nil
-    }
-
-    func precedingCharacter(in file: SwiftLintFile) -> Character? {
-        guard let startingCharacterPosition = startingCharacterPosition(in: file),
-              let line = lineOfCommand(in: file) else {
-            return nil
+    func isPrecededByInvalidCharacter(in file: SwiftLintFile) -> Bool {
+        guard line > 0, let character, character > 1, line <= file.lines.count else {
+            return false
         }
-        guard line.distance(from: line.startIndex, to: startingCharacterPosition) > 2 else {
-            return nil
+        let line = file.lines[line - 1].content
+        guard line.count > character,
+              let char = line[line.index(line.startIndex, offsetBy: character - 2)].unicodeScalars.first else {
+            return false
         }
-        return line[line.index(startingCharacterPosition, offsetBy: -2)...].first
+        return !CharacterSet.whitespaces.union(CharacterSet(charactersIn: "/")).contains(char)
     }
 
     func invalidReason() -> String? {

Source/SwiftLintCore/Extensions/String+SwiftLint.swift

@@ -128,4 +128,17 @@ public extension String {
     func linesPrefixed(with prefix: Self) -> Self {
         split(separator: "\n").joined(separator: "\n\(prefix)")
     }
+
+    func characterPosition(of utf8Offset: Int) -> Int? {
+        guard utf8Offset != 0 else {
+            return 0
+        }
+        guard utf8Offset > 0, utf8Offset < lengthOfBytes(using: .utf8) else {
+            return nil
+        }
+        for (offset, index) in indices.enumerated() where self[...index].lengthOfBytes(using: .utf8) == utf8Offset {
+            return offset + 1
+        }
+        return nil
+    }
 }

Source/SwiftLintCore/Models/Command.swift

@@ -51,7 +51,7 @@ public struct Command: Equatable {
     public let ruleIdentifiers: Set<RuleIdentifier>
     /// The line in the source file where this command is defined.
     public let line: Int
-    /// The character offset within the line in the source file where this command is defined.
+    /// The character offset within the line in the source file where this command starts.
     public let character: Int?
     /// This command's modifier, if any.
     public let modifier: Modifier?
@@ -63,8 +63,7 @@ public struct Command: Equatable {
     /// - parameter action:          This command's action.
     /// - parameter ruleIdentifiers: The identifiers for the rules associated with this command.
     /// - parameter line:            The line in the source file where this command is defined.
-    /// - parameter character:       The character offset within the line in the source file where this command is
-    ///                              defined.
+    /// - parameter character:       The character offset within the line in the source file where this command starts.
     /// - parameter modifier:        This command's modifier, if any.
     /// - parameter trailingComment: The comment following this command's `-` delimiter, if any.
     public init(action: Action,
@@ -85,8 +84,7 @@ public struct Command: Equatable {
     ///
     /// - parameter actionString: The string in the command's definition describing its action.
     /// - parameter line:         The line in the source file where this command is defined.
-    /// - parameter character:    The character offset within the line in the source file where this command is
-    ///                           defined.
+    /// - parameter character:    The character offset within the line in the source file where this command starts.
     public init(actionString: String, line: Int, character: Int) {
         let scanner = Scanner(string: actionString)
         _ = scanner.scanString("swiftlint:")

Source/SwiftLintCore/Visitors/CommandVisitor.swift

@@ -13,37 +13,34 @@ final class CommandVisitor: SyntaxVisitor {
     }
 
     override func visitPost(_ node: TokenSyntax) {
-        let leadingCommands = node.leadingTrivia.commands(offset: node.position,
-                                                          locationConverter: locationConverter)
-        let trailingCommands = node.trailingTrivia.commands(offset: node.endPositionBeforeTrailingTrivia,
-                                                            locationConverter: locationConverter)
-        self.commands.append(contentsOf: leadingCommands + trailingCommands)
+        collectCommands(in: node.leadingTrivia, offset: node.position)
+        collectCommands(in: node.trailingTrivia, offset: node.endPositionBeforeTrailingTrivia)
     }
-}
-
-// MARK: - Private Helpers
 
-private extension Trivia {
-    func commands(offset: AbsolutePosition, locationConverter: SourceLocationConverter) -> [Command] {
-        var triviaOffset = SourceLength.zero
-        var results: [Command] = []
-        for trivia in self {
-            triviaOffset += trivia.sourceLength
-            switch trivia {
+    private func collectCommands(in trivia: Trivia, offset: AbsolutePosition) {
+        var position = offset
+        for piece in trivia {
+            switch piece {
             case .lineComment(let comment):
-                guard let lower = comment.range(of: "swiftlint:")?.lowerBound else {
+                guard let lower = comment.range(of: "swiftlint:")?.lowerBound.samePosition(in: comment.utf8) else {
                     break
                 }
-
-                let actionString = String(comment[lower...])
-                let end = locationConverter.location(for: offset + triviaOffset)
-                let command = Command(actionString: actionString, line: end.line, character: end.column)
-                results.append(command)
+                let offset = comment.utf8.distance(from: comment.utf8.startIndex, to: lower)
+                let location = locationConverter.location(for: position.advanced(by: offset))
+                let line = locationConverter.sourceLines[location.line - 1]
+                guard let character = line.characterPosition(of: location.column) else {
+                    break
+                }
+                let command = Command(
+                    actionString: String(comment[lower...]),
+                    line: location.line,
+                    character: character
+                )
+                commands.append(command)
             default:
                 break
             }
+            position += piece.sourceLength
         }
-
-        return results
     }
 }