Add ability to force color output for non-TTYs

CHANGELOG.md

@@ -2,11 +2,11 @@
 
 ##### Breaking
 
-- None.
+- The `--no-color` option has been replaced with `--color=never`.
 
 ##### Enhancements
 
-- None.
+- The `--color` option now accepts one of `auto`, `always` and `never`. In `auto` mode, color is disabled for dumb terminals and non-TTYs.
 
 ##### Bug Fixes
 

Sources/BUILD.bazel

@@ -275,6 +275,7 @@ swift_library(
 swift_library(
     name = "Configuration",
     srcs = [
+        "Configuration/ColorOption.swift",
         "Configuration/Configuration.swift",
         "Configuration/OutputFormat.swift",
     ],

Sources/Configuration/ColorOption.swift

@@ -0,0 +1,17 @@
+public enum ColorOption: String, CaseIterable, Equatable {
+    case auto
+    case always
+    case never
+
+    public static let `default` = ColorOption.auto
+
+    init?(anyValue: Any) {
+        if let option = anyValue as? ColorOption {
+            self = option
+            return
+        }
+        guard let stringValue = anyValue as? String else { return nil }
+
+        self.init(rawValue: stringValue)
+    }
+}

Sources/Configuration/Configuration.swift

@@ -98,8 +98,8 @@ public final class Configuration {
     @Setting(key: "quiet", defaultValue: false)
     public var quiet: Bool
 
-    @Setting(key: "color", defaultValue: true)
-    public var color: Bool
+    @Setting(key: "color", defaultValue: .default, setter: { ColorOption(anyValue: $0) })
+    public var color: ColorOption
 
     @Setting(key: "disable_update_check", defaultValue: false)
     public var disableUpdateCheck: Bool
@@ -174,7 +174,7 @@ public final class Configuration {
 
         let encodedYAML = try String(contentsOf: path.url, encoding: .utf8)
         let yaml = try Yams.load(yaml: encodedYAML) as? [String: Any] ?? [:]
-        let logger = Logger(quiet: false, verbose: false, coloredOutputEnabled: false)
+        let logger = Logger(quiet: false, verbose: false, colorMode: .never)
 
         for (key, value) in yaml {
             if let setting = settings.first(where: { key == $0.key }) {
@@ -338,3 +338,9 @@ extension FilePath: Yams.ScalarRepresentable {
         string.represented()
     }
 }
+
+extension ColorOption: Yams.ScalarRepresentable {
+    public func represented() -> Node.Scalar {
+        rawValue.represented()
+    }
+}

Sources/Frontend/Commands/ScanCommand.swift

@@ -30,7 +30,7 @@ struct ScanCommand: ParsableCommand {
     @Option(parsing: .upToNextOption, help: "Schemes to build. All targets built by these schemes will be scanned")
     var schemes: [String] = defaultConfiguration.$schemes.defaultValue
 
-    @Option(help: "Output format (allowed: \(OutputFormat.allValueStrings.joined(separator: ", ")))")
+    @Option(help: "Output format")
     var format: OutputFormat = defaultConfiguration.$outputFormat.defaultValue
 
     @Flag(help: "Exclude test targets from indexing")
@@ -126,8 +126,11 @@ struct ScanCommand: ParsableCommand {
     @Flag(help: "Only output results")
     var quiet: Bool = defaultConfiguration.$quiet.defaultValue
 
-    @Flag(inversion: .prefixedNo, help: "Colored output")
-    var color: Bool = defaultConfiguration.$color.defaultValue
+    @Option(help: "Colored output mode")
+    var color: ColorOption = defaultConfiguration.$color.defaultValue
+
+    @Flag(name: .customLong("no-color"), help: .hidden)
+    var noColor: Bool = false
 
     @Option(help: "JSON package manifest path (obtained using `swift package describe --type json` or manually)")
     var jsonPackageManifestPath: FilePath?
@@ -191,7 +194,7 @@ struct ScanCommand: ParsableCommand {
         configuration.apply(\.$externalTestCaseClasses, externalTestCaseClasses)
         configuration.apply(\.$verbose, verbose)
         configuration.apply(\.$quiet, quiet)
-        configuration.apply(\.$color, color)
+        configuration.apply(\.$color, noColor ? .never : color)
         configuration.apply(\.$disableUpdateCheck, disableUpdateCheck)
         configuration.apply(\.$strict, strict)
         configuration.apply(\.$indexStorePath, indexStorePath)
@@ -268,7 +271,7 @@ struct ScanCommand: ParsableCommand {
 
         let outputFormat = configuration.outputFormat
         let formatter = outputFormat.formatter.init(configuration: configuration, logger: logger)
-        let colored = outputFormat.supportsColoredOutput && configuration.color
+        let colored = outputFormat.supportsColoredOutput && logger.isColoredOutputEnabled
 
         if let output = try formatter.format(filteredResults, colored: colored) {
             if outputFormat.supportsAuxiliaryOutput {
@@ -309,6 +312,7 @@ struct ScanCommand: ParsableCommand {
 }
 
 extension OutputFormat: ExpressibleByArgument {}
+extension ColorOption: ExpressibleByArgument {}
 
 extension FilePath: ArgumentParser.ExpressibleByArgument {
     public init?(argument: String) {

Sources/Frontend/Logger+Extension.swift

@@ -4,10 +4,15 @@ import Logger
 public extension Logger {
     @inlinable
     init(configuration: Configuration) {
+        let colorMode: LoggerColorMode = switch configuration.color {
+        case .auto: .auto
+        case .always: .always
+        case .never: .never
+        }
         self.init(
             quiet: configuration.quiet,
             verbose: configuration.verbose,
-            coloredOutputEnabled: configuration.color
+            colorMode: colorMode
         )
     }
 }

Sources/Logger/Logger.swift

@@ -21,40 +21,46 @@ public enum ANSIColor: String {
     case gray = "\u{001B}[0;1;30m"
 }
 
+public enum LoggerColorMode: Sendable {
+    case auto
+    case always
+    case never
+}
+
 public struct Logger: Sendable {
     let outputQueue: DispatchQueue
     let quiet: Bool
     let verbose: Bool
-    let coloredOutputEnabled: Bool
+    let colorMode: LoggerColorMode
 
     #if canImport(os)
         let signposter = OSSignposter()
     #endif
 
-    private var isColorOutputCapable: Bool = {
-        guard let term = ProcessInfo.processInfo.environment["TERM"],
-              term.lowercased() != "dumb",
-              isatty(fileno(stdout)) != 0
-        else {
-            return false
+    public var isColoredOutputEnabled: Bool {
+        switch colorMode {
+        case .auto:
+            isColorOutputCapable
+        case .always:
+            true
+        case .never:
+            false
         }
-
-        return true
-    }()
+    }
 
     public init(
         quiet: Bool,
         verbose: Bool,
-        coloredOutputEnabled: Bool
+        colorMode: LoggerColorMode
     ) {
         self.quiet = quiet
         self.verbose = verbose
-        self.coloredOutputEnabled = coloredOutputEnabled
+        self.colorMode = colorMode
         outputQueue = DispatchQueue(label: "Logger.outputQueue")
     }
 
     public func colorize(_ text: String, _ color: ANSIColor) -> String {
-        guard isColorOutputCapable, coloredOutputEnabled else { return text }
+        guard isColoredOutputEnabled else { return text }
 
         return "\(color.rawValue)\(text)\u{001B}[0;0m"
     }
@@ -112,6 +118,17 @@ public struct Logger: Sendable {
     func log(_ line: String, output: UnsafeMutablePointer<FILE>) {
         _ = outputQueue.sync { fputs(line + "\n", output) }
     }
+
+    private var isColorOutputCapable: Bool = {
+        guard let term = ProcessInfo.processInfo.environment["TERM"],
+              term.lowercased() != "dumb",
+              isatty(fileno(stdout)) != 0
+        else {
+            return false
+        }
+
+        return true
+    }()
 }
 
 public struct ContextualLogger: Sendable {

Tests/PeripheryTests/Syntax/FunctionVisitTest.swift

@@ -11,7 +11,7 @@ final class FunctionVisitTest: XCTestCase {
 
     override func setUpWithError() throws {
         try super.setUpWithError()
-        let shell = ShellImpl(logger: Logger(quiet: true, verbose: false, coloredOutputEnabled: false))
+        let shell = ShellImpl(logger: Logger(quiet: true, verbose: false, colorMode: .never))
         let swiftVersion = SwiftVersion(shell: shell)
         let multiplexingVisitor = try MultiplexingSyntaxVisitor(file: fixturePath, swiftVersion: swiftVersion)
         let visitor = multiplexingVisitor.add(DeclarationSyntaxVisitor.self)

Tests/PeripheryTests/Syntax/ImportVisitTest.swift

@@ -11,7 +11,7 @@ final class ImportVisitTest: XCTestCase {
 
     override func setUpWithError() throws {
         try super.setUpWithError()
-        let shell = ShellImpl(logger: Logger(quiet: true, verbose: false, coloredOutputEnabled: false))
+        let shell = ShellImpl(logger: Logger(quiet: true, verbose: false, colorMode: .never))
         let swiftVersion = SwiftVersion(shell: shell)
         let multiplexingVisitor = try MultiplexingSyntaxVisitor(file: fixturePath, swiftVersion: swiftVersion)
         let visitor = multiplexingVisitor.add(ImportSyntaxVisitor.self)

Tests/PeripheryTests/Syntax/PropertyVisitTest.swift

@@ -11,7 +11,7 @@ final class PropertyVisitTest: XCTestCase {
 
     override func setUpWithError() throws {
         try super.setUpWithError()
-        let shell = ShellImpl(logger: Logger(quiet: true, verbose: false, coloredOutputEnabled: false))
+        let shell = ShellImpl(logger: Logger(quiet: true, verbose: false, colorMode: .never))
         let swiftVersion = SwiftVersion(shell: shell)
         let multiplexingVisitor = try MultiplexingSyntaxVisitor(file: fixturePath, swiftVersion: swiftVersion)
         let visitor = multiplexingVisitor.add(DeclarationSyntaxVisitor.self)

Tests/Shared/SourceGraphTestCase.swift

@@ -21,7 +21,7 @@ open class SourceGraphTestCase: XCTestCase {
 
     override open class func setUp() {
         super.setUp()
-        logger = Logger(quiet: true, verbose: false, coloredOutputEnabled: false)
+        logger = Logger(quiet: true, verbose: false, colorMode: .never)
         shell = ShellImpl(logger: logger)
         swiftVersion = SwiftVersion(shell: shell)
         let configuration = Configuration()

Tests/XcodeTests/XcodeTargetTest.swift

@@ -11,7 +11,7 @@ final class XcodeTargetTest: XCTestCase {
 
     override func setUp() {
         super.setUp()
-        let logger = Logger(quiet: true, verbose: false, coloredOutputEnabled: false)
+        let logger = Logger(quiet: true, verbose: false, colorMode: .never)
         let shell = ShellImpl(logger: logger)
         let xcodebuild = Xcodebuild(shell: shell, logger: logger)
         var loadedProjectPaths: Set<FilePath> = []

Tests/XcodeTests/XcodebuildBuildProjectTest.swift

@@ -12,7 +12,7 @@ final class XcodebuildBuildProjectTest: XCTestCase {
     override func setUp() {
         super.setUp()
 
-        let logger = Logger(quiet: true, verbose: false, coloredOutputEnabled: false)
+        let logger = Logger(quiet: true, verbose: false, colorMode: .never)
         let shell = ShellImpl(logger: logger)
         var loadedProjectPaths: Set<FilePath> = []
         xcodebuild = Xcodebuild(shell: shell, logger: logger)

Tests/XcodeTests/XcodebuildSchemesTest.swift

@@ -8,7 +8,7 @@ final class XcodebuildSchemesTest: XCTestCase {
     func testParseSchemes() {
         for output in XcodebuildListOutputs {
             let shell = ShellMock(output: output)
-            let logger = Logger(quiet: true, verbose: false, coloredOutputEnabled: false)
+            let logger = Logger(quiet: true, verbose: false, colorMode: .never)
             var loadedProjectPaths: Set<FilePath> = []
             let xcodebuild = Xcodebuild(shell: shell, logger: logger)
             let project = try! XcodeProject(path: UIKitProjectPath, loadedProjectPaths: &loadedProjectPaths, xcodebuild: xcodebuild, shell: shell, logger: logger)