Merge pull request #26 from jamf/ml_StrictConcurrency_minor_updates

Minor updates for StrictConcurrency and documentation updates

Author: mlink

.github/workflows/build-and-test.yml

@@ -13,32 +13,32 @@ on:
 jobs:
   spm:
     name: SwiftPM build and test
-    runs-on: macos-13
+    runs-on: macos-14
     steps:
     - run: |
-        sudo xcode-select -s /Applications/Xcode_15.0.app
+        sudo xcode-select -s /Applications/Xcode_15.3.app
     - uses: actions/checkout@v3
     - name: Build swift packages
       run: swift build -v
     - name: Run tests
       run: swift test -v
   carthage:
     name: Xcode project build and test
-    runs-on: macos-13
+    runs-on: macos-14
     steps:
     - run: |
-        sudo xcode-select -s /Applications/Xcode_15.0.app
+        sudo xcode-select -s /Applications/Xcode_15.3.app
     - uses: actions/checkout@v3
     - name: Build xcode project
       run: xcodebuild build -scheme 'SubprocessMocks' -derivedDataPath .build
     - name: Run tests
       run: xcodebuild test -scheme 'Subprocess' -derivedDataPath .build
   cocoapods:
     name: Pod lib lint
-    runs-on: macos-13
+    runs-on: macos-14
     steps:
     - run: |
-        sudo xcode-select -s /Applications/Xcode_15.0.app
+        sudo xcode-select -s /Applications/Xcode_15.3.app
     - uses: actions/checkout@v3
     - name: Lib lint
       run: pod lib lint --verbose Subprocess.podspec --allow-warnings

CHANGELOG.md

@@ -7,6 +7,12 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## 3.0.3 - 2024-04-15
+
+### Changed
+- Correctly turned on `StrictConcurrency` in Swift 5.10 and earlier and added non-breaking conformance to `Sendable`.
+- Updated documentation for closure based usage where `nonisolated(unsafe)` is required to avoid an error in projects that use `StrictConcurrency`.
+
 ## 3.0.2 - 2024-02-07
 
 ### Added

Package.swift

@@ -1,20 +1,7 @@
-// swift-tools-version: 5.9
+// swift-tools-version: 5.10
 
 import PackageDescription
 
-#if swift(<6)
-let swiftSettings: [SwiftSetting] = [
-    .enableUpcomingFeature("StrictConcurrency"),
-    .enableUpcomingFeature("ExistentialAny"),
-    .enableUpcomingFeature("ForwardTrailingClosures"),
-    .enableUpcomingFeature("ImplicitOpenExistentials"),
-    .enableUpcomingFeature("BareSlashRegexLiterals"),
-    .enableUpcomingFeature("ConciseMagicFile"),
-]
-#else
-let swiftSettings: [SwiftSetting] = []
-#endif
-
 let package = Package(
     name: "Subprocess",
     platforms: [ .macOS("10.15.4") ],
@@ -46,30 +33,92 @@ let package = Package(
     targets: [
         .target(
             name: "Subprocess",
-            dependencies: [],
-            swiftSettings: swiftSettings
+            dependencies: []
         ),
         .target(
             name: "SubprocessMocks",
             dependencies: [
                 .target(name: "Subprocess")
-            ],
-            swiftSettings: swiftSettings
+            ]
         ),
         .testTarget(
             name: "UnitTests",
             dependencies: [
                 .target(name: "Subprocess"),
                 .target(name: "SubprocessMocks")
-            ],
-            swiftSettings: swiftSettings
+            ]
         ),
         .testTarget(
             name: "SystemTests",
             dependencies: [
                 .target(name: "Subprocess")
-            ],
-            swiftSettings: swiftSettings
+            ]
         )
     ]
 )
+
+for target in package.targets {
+    var swiftSettings = target.swiftSettings ?? []
+    
+    // According to Swift's piecemeal adoption plan features that were
+    // upcoming features that become language defaults and are still enabled
+    // as upcoming features will result in a compiler error. Currently in the
+    // latest 5.10 compiler this doesn't happen, the compiler ignores it.
+    //
+    // If the situation does change and enabling default language features
+    // does result in an error in future versions we attempt to guard against
+    // this by using the hasFeature(x) compiler directive to see if we have a
+    // feature already, or if we can enable it. It's safe to enable features
+    // that don't exist in older compiler versions as the compiler will ignore
+    // features it doesn't have implemented.
+    
+    // swift 6
+    #if !hasFeature(ConciseMagicFile)
+    swiftSettings.append(.enableUpcomingFeature("ConciseMagicFile"))
+    #endif
+
+    #if !hasFeature(ForwardTrailingClosures)
+    swiftSettings.append(.enableUpcomingFeature("ForwardTrailingClosures"))
+    #endif
+
+    #if !hasFeature(StrictConcurrency)
+    swiftSettings.append(.enableUpcomingFeature("StrictConcurrency"))
+    // StrictConcurrency is under experimental features in Swift <=5.10 contrary to some posts and documentation
+    swiftSettings.append(.enableExperimentalFeature("StrictConcurrency"))
+    #endif
+
+    #if !hasFeature(BareSlashRegexLiterals)
+    swiftSettings.append(.enableUpcomingFeature("BareSlashRegexLiterals"))
+    #endif
+
+    #if !hasFeature(ImplicitOpenExistentials)
+    swiftSettings.append(.enableUpcomingFeature("ImplicitOpenExistentials"))
+    #endif
+
+    #if !hasFeature(ImportObjcForwardDeclarations)
+    swiftSettings.append(.enableUpcomingFeature("ImportObjcForwardDeclarations"))
+    #endif
+
+    #if !hasFeature(DisableOutwardActorInference)
+    swiftSettings.append(.enableUpcomingFeature("DisableOutwardActorInference"))
+    #endif
+
+    #if !hasFeature(InternalImportsByDefault)
+    swiftSettings.append(.enableUpcomingFeature("InternalImportsByDefault"))
+    #endif
+    
+    #if !hasFeature(IsolatedDefaultValues)
+    swiftSettings.append(.enableUpcomingFeature("IsolatedDefaultValues"))
+    #endif
+    
+    #if !hasFeature(GlobalConcurrency)
+    swiftSettings.append(.enableUpcomingFeature("GlobalConcurrency"))
+    #endif
+
+    // swift 7
+    #if !hasFeature(ExistentialAny)
+    swiftSettings.append(.enableUpcomingFeature("ExistentialAny"))
+    #endif
+    
+    target.swiftSettings = swiftSettings
+}

README.md

@@ -137,12 +137,16 @@ if process.exitCode == 0 {
 ```swift
 let command: [String] = ...
 let process = Subprocess(command)
+nonisolated(unsafe) var outputData: Data?
+nonisolated(unsafe) var errorData: Data?
 
 // The outputHandler and errorHandler are invoked serially
 try process.launch(outputHandler: { data in
     // Handle new data read from stdout
+    outputData = data 
 }, errorHandler: { data in
     // Handle new data read from stderr
+    errorData = data
 }, terminationHandler: { process in
     // Handle process termination, all scheduled calls to
     // the outputHandler and errorHandler are guaranteed to

Sources/Subprocess/Pipe+AsyncBytes.swift

@@ -38,7 +38,7 @@ extension Pipe {
 
         public func makeAsyncIterator() -> AsyncStream<Element>.Iterator {
             AsyncStream { continuation in
-                pipe.fileHandleForReading.readabilityHandler = { handle in
+                pipe.fileHandleForReading.readabilityHandler = { @Sendable handle in
                     let availableData = handle.availableData
 
                     guard !availableData.isEmpty else {

Sources/Subprocess/Shell.swift

@@ -32,7 +32,7 @@ import Foundation
 public class Shell {
 
     /// OptionSet representing output handling
-    public struct OutputOptions: OptionSet {
+    public struct OutputOptions: OptionSet, Sendable {
         public let rawValue: Int
 
         /// Processes data written to stdout

Sources/Subprocess/Subprocess.swift

@@ -31,7 +31,7 @@ import Combine
 /// Class used for asynchronous process execution
 public class Subprocess: @unchecked Sendable {
     /// Output options.
-    public struct OutputOptions: OptionSet {
+    public struct OutputOptions: OptionSet, Sendable {
         public let rawValue: Int
 
         /// Buffer standard output.
@@ -118,7 +118,7 @@ public class Subprocess: @unchecked Sendable {
     ///
     /// It is the callers responsibility to ensure that any reads occur if waiting for the process to exit otherwise a deadlock can happen if the process is waiting to write to its output buffer.
     /// A task group can be used to wait for exit while reading the output. If the output is discardable consider passing (`[]`) an empty set for the options which effectively flushes output to null.
-    public func run(options: OutputOptions = [.standardOutput, .standardError]) throws -> (standardOutput: Pipe.AsyncBytes, standardError: Pipe.AsyncBytes, waitUntilExit: () async -> Void) {
+    public func run(options: OutputOptions = [.standardOutput, .standardError]) throws -> (standardOutput: Pipe.AsyncBytes, standardError: Pipe.AsyncBytes, waitUntilExit: @Sendable () async -> Void) {
         let standardOutput: Pipe.AsyncBytes = {
             if options.contains(.standardOutput) {
                 let pipe = Pipe()
@@ -162,7 +162,7 @@ public class Subprocess: @unchecked Sendable {
                 }
             }
         }
-        let waitUntilExit = {
+        let waitUntilExit = { @Sendable in
             await task.value
         }
 
@@ -216,7 +216,7 @@ public class Subprocess: @unchecked Sendable {
     ///         }
     ///     }
     ///
-    public func run<Input>(standardInput: Input, options: OutputOptions = [.standardOutput, .standardError]) throws -> (standardOutput: Pipe.AsyncBytes, standardError: Pipe.AsyncBytes, waitUntilExit: () async -> Void) where Input : AsyncSequence, Input.Element == UInt8 {
+    public func run<Input>(standardInput: Input, options: OutputOptions = [.standardOutput, .standardError]) throws -> (standardOutput: Pipe.AsyncBytes, standardError: Pipe.AsyncBytes, waitUntilExit: @Sendable () async -> Void) where Input : AsyncSequence, Input.Element == UInt8 {
         process.standardInput = try SubprocessDependencyBuilder.shared.makeInputPipe(sequence: standardInput)
         return try run(options: options)
     }

Sources/Subprocess/SubprocessDependencyBuilder.swift

@@ -52,7 +52,7 @@ public protocol SubprocessDependencyFactory {
 /// Default implementation of SubprocessDependencyFactory
 public struct SubprocessDependencyBuilder: SubprocessDependencyFactory {
     private static let queue = DispatchQueue(label: "\(Self.self)")
-    private static var _shared: any SubprocessDependencyFactory = SubprocessDependencyBuilder()
+    nonisolated(unsafe) private static var _shared: any SubprocessDependencyFactory = SubprocessDependencyBuilder()
     /// Shared instance used for dependency creation
     public static var shared: any SubprocessDependencyFactory {
         get {
@@ -80,7 +80,7 @@ public struct SubprocessDependencyBuilder: SubprocessDependencyFactory {
         return try FileHandle(forReadingFrom: url)
     }
 
-    public func makeInputPipe<Input>(sequence: Input) throws -> Pipe where Input : AsyncSequence, Input.Element == UInt8 {
+    public func makeInputPipe<Input>(sequence: Input) throws -> Pipe where Input : AsyncSequence & Sendable, Input.Element == UInt8 {
         let pipe = Pipe()
         // see here: https://developer.apple.com/forums/thread/690382
         let result = fcntl(pipe.fileHandleForWriting.fileDescriptor, F_SETNOSIGPIPE, 1)

Sources/SubprocessMocks/MockOutput.swift

@@ -28,7 +28,7 @@
 import Foundation
 
 /// A way to supply data to mock methods
-public protocol MockOutput {
+public protocol MockOutput: Sendable {
     var data: Data { get }
 }
 

Sources/SubprocessMocks/MockProcess.swift

@@ -31,7 +31,7 @@ import Subprocess
 #endif
 
 /// Interface used for mocking a process
-public struct MockProcess {
+public struct MockProcess: Sendable {
 
     /// The underlying `MockProcessReference`
     public var reference: MockProcessReference
@@ -100,7 +100,7 @@ open class MockProcessReference: Process {
 
     /// Creates a new `MockProcessReference` calling run stub block
     /// - Parameter block: Block used to stub `Process.run`
-    public init(withRunBlock block: @escaping (MockProcess) -> Void) {
+    public init(withRunBlock block: @escaping @Sendable (MockProcess) -> Void) {
         context = Context(runStub: { mock in
             Task(priority: .userInitiated) {
                 block(mock)

Sources/SubprocessMocks/MockSubprocess.swift

@@ -51,7 +51,7 @@ public extension Subprocess {
     /// - Parameters:
     ///     - command: The command to mock
     ///     - runBlock: Block called with a `MockProcess` to mock process execution.
-    static func stub(_ command: [String], runBlock: ((MockProcess) -> Void)? = nil) {
+    static func stub(_ command: [String], runBlock: (@Sendable (MockProcess) -> Void)? = nil) {
         let mock = MockProcessReference(withRunBlock: runBlock ?? { $0.exit() })
         MockSubprocessDependencyBuilder.shared.stub(command, process: mock)
     }
@@ -116,7 +116,7 @@ public extension Subprocess {
     ///     - file: Source file where expect was called (Default: #file)
     ///     - line: Line number of source file where expect was called (Default: #line)
     ///     - runBlock: Block called with a `MockProcess` to mock process execution
-    static func expect(_ command: [String], input: Input? = nil, file: StaticString = #file, line: UInt = #line, runBlock: ((MockProcess) -> Void)? = nil) {
+    static func expect(_ command: [String], input: Input? = nil, file: StaticString = #file, line: UInt = #line, runBlock: (@Sendable (MockProcess) -> Void)? = nil) {
         let mock = MockProcessReference(withRunBlock: runBlock ?? { $0.exit() })
         MockSubprocessDependencyBuilder.shared.expect(command, input: input, process: mock, file: file, line: line)
     }

Sources/SubprocessMocks/MockSubprocessDependencyBuilder.swift

@@ -88,7 +88,6 @@ public final class MockPipe: Pipe {
 }
 
 class MockSubprocessDependencyBuilder {
-
     class MockItem {
         var used = false
         var command: [String]
@@ -108,7 +107,7 @@ class MockSubprocessDependencyBuilder {
 
     var mocks: [MockItem] = []
 
-    static let shared = MockSubprocessDependencyBuilder()
+    nonisolated(unsafe) static let shared = MockSubprocessDependencyBuilder()
 
     init() { SubprocessDependencyBuilder.shared = self }
 
@@ -242,7 +241,7 @@ extension MockSubprocessDependencyBuilder: SubprocessDependencyFactory {
         return handle
     }
 
-    func makeInputPipe<Input>(sequence: Input) throws -> Pipe where Input : AsyncSequence, Input.Element == UInt8 {
+    func makeInputPipe<Input>(sequence: Input) throws -> Pipe where Input : AsyncSequence & Sendable, Input.Element == UInt8 {
         let semaphore = DispatchSemaphore(value: 0)
         let pipe = MockPipe()
 

Tests/SystemTests/SubprocessSystemTests.swift

@@ -86,7 +86,7 @@ final class SubprocessSystemTests: XCTestCase {
                 switch line {
                 case "hello":
                     Task {
-                        input.yield("world\n")
+                        _ = input.yield("world\n")
                     }
                 case "world":
                     input.yield("and\nuniverse")

Tests/UnitTests/SubprocessTests.swift

@@ -103,7 +103,7 @@ final class SubprocessTests: XCTestCase {
     func testGetPID() throws {
         // Given
         let mockCalled = expectation(description: "Mock setup called")
-        var expectedPID: Int32?
+        nonisolated(unsafe) var expectedPID: Int32?
         Subprocess.expect(command) { mock in
             expectedPID = mock.reference.processIdentifier
             mockCalled.fulfill()
@@ -185,7 +185,7 @@ final class SubprocessTests: XCTestCase {
 
     // MARK: suspend
 
-    func testSuspend() throws {
+    @MainActor func testSuspend() throws {
         // Given
         let semaphore = DispatchSemaphore(value: 0)
         let suspendCalled = expectation(description: "Suspend called")
@@ -210,7 +210,7 @@ final class SubprocessTests: XCTestCase {
 
     // MARK: resume
 
-    func testResume() throws {
+    @MainActor func testResume() throws {
         // Given
         let semaphore = DispatchSemaphore(value: 0)
         let resumeCalled = expectation(description: "Resume called")
@@ -235,7 +235,7 @@ final class SubprocessTests: XCTestCase {
 
     // MARK: kill
 
-    func testKill() throws {
+    @MainActor func testKill() throws {
         // Given
         let semaphore = DispatchSemaphore(value: 0)
         let terminateCalled = expectation(description: "Terminate called")