[CI] Unblock stale runners and fix modern Swift build errors

.github/workflows/compatibility_tests.yml

@@ -13,7 +13,7 @@ jobs:
       fail-fast: false
       matrix:
         include:
-          - os: macos-13
+          - os: macos-14
             xcode-version: "15.2"   # Swift 5.9.2
     runs-on: ${{ matrix.os }}
     steps:

.github/workflows/macos.yml

@@ -13,8 +13,14 @@ jobs:
       fail-fast: false
       matrix:
         include:
-          - os: macos-13
-            xcode-version: "15.2"   # Swift 5.9.2
+          - os: macos-14
+            xcode-version: "15.2"   # Swift 5.9.2 (minimum supported)
+            # TODO: drop this once the Swift 6 Sendable/Concurrency warnings
+            # in the schedulers and test doubles are resolved.
+            warnings-as-errors: "-Xswiftc -warnings-as-errors"
+          - os: macos-15
+            xcode-version: "16.4"   # Current Swift
+            warnings-as-errors: ""
     runs-on: ${{ matrix.os }}
     steps:
       - uses: actions/checkout@v4
@@ -28,7 +34,7 @@ jobs:
         run: |
           swift test \
             -c debug \
-            -Xswiftc -warnings-as-errors \
+            ${{ matrix.warnings-as-errors }} \
             --enable-code-coverage \
             --build-path .build-test-debug
           xcrun llvm-cov show \
@@ -40,16 +46,15 @@ jobs:
           swift test \
           -c debug \
           --sanitize thread \
-          -Xswiftc -warnings-as-errors \
+          ${{ matrix.warnings-as-errors }} \
           --build-path .build-test-debug-sanitize-thread
       - name: Build and run tests in release mode
-        if: ${{ matrix.xcode-version != '14.3.1' }} # error: no input files specified. See llvm-profdata merge -help
         run: |
           swift test \
             -c release \
-            -Xswiftc -warnings-as-errors \
+            ${{ matrix.warnings-as-errors }} \
             --enable-code-coverage \
             --build-path .build-test-release
-      - uses: codecov/codecov-action@v3
+      - uses: codecov/codecov-action@v4
         with:
           verbose: true

.github/workflows/ubuntu.yml

@@ -12,22 +12,24 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        swift_version: ["5.9.2"]
-        os: [ubuntu-20.04, ubuntu-22.04]
         include:
-          - os: ubuntu-20.04
-            os_name: focal
-          - os: ubuntu-22.04
-            os_name: jammy
-    runs-on: ${{ matrix.os }}
-    container: swift:${{ matrix.swift_version }}-${{ matrix.os_name }}
+          - swift_image: "5.9.2-jammy"   # Swift 5.9.2 (minimum supported)
+            # TODO: drop this once the Swift 6 Sendable/Concurrency warnings
+            # in the schedulers and test doubles are resolved.
+            warnings-as-errors: "-Xswiftc -warnings-as-errors"
+          - swift_image: "6.1-noble"     # Current Swift
+            warnings-as-errors: ""
+    runs-on: ubuntu-latest
+    container: swift:${{ matrix.swift_image }}
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
+      - name: Swift version
+        run: swift --version
       - name: Building and running tests in debug mode with coverage
         run: |
           swift test \
             -c debug \
-            -Xswiftc -warnings-as-errors \
+            ${{ matrix.warnings-as-errors }} \
             --enable-code-coverage \
             --build-path .build-test-debug
           llvm-cov show \
@@ -44,8 +46,8 @@ jobs:
         run: |
           swift test \
             -c release \
-            -Xswiftc -warnings-as-errors \
+            ${{ matrix.warnings-as-errors }} \
             --build-path .build-test-release
-      - uses: codecov/codecov-action@v3
+      - uses: codecov/codecov-action@v4
         with:
           verbose: true

Sources/OpenCombine/CombineIdentifier.swift

@@ -6,8 +6,12 @@
 //
 
 #if canImport(COpenCombineHelpers)
+#if compiler(>=6.0)
+internal import COpenCombineHelpers
+#else
 @_implementationOnly import COpenCombineHelpers
 #endif
+#endif
 
 #if os(WASI)
 private var __identifier: UInt64 = 0

Sources/OpenCombine/Helpers/Locking.swift

@@ -6,8 +6,12 @@
 //
 
 #if canImport(COpenCombineHelpers)
+#if compiler(>=6.0)
+internal import COpenCombineHelpers
+#else
 @_implementationOnly import COpenCombineHelpers
 #endif
+#endif
 
 #if os(WASI)
 internal struct __UnfairLock { // swiftlint:disable:this type_name

Sources/OpenCombine/Publishers/Publishers.Breakpoint.swift

@@ -8,8 +8,12 @@
 #if !os(WASI)
 
 #if canImport(COpenCombineHelpers)
+#if compiler(>=6.0)
+internal import COpenCombineHelpers
+#else
 @_implementationOnly import COpenCombineHelpers
 #endif
+#endif
 
 extension Publisher {
 

Sources/OpenCombine/Publishers/Publishers.Merge.swift

@@ -6,8 +6,12 @@
 //  Audited for 2023 Release
 
 #if canImport(COpenCombineHelpers)
+#if compiler(>=6.0)
+internal import COpenCombineHelpers
+#else
 @_implementationOnly import COpenCombineHelpers
 #endif
+#endif
 
 // MARK: - merge methods on Publisher
 

Sources/OpenCombine/Publishers/Publishers.Zip.swift

@@ -6,8 +6,12 @@
 //  Audited for 2023 Release
 
 #if canImport(COpenCombineHelpers)
+#if compiler(>=6.0)
+internal import COpenCombineHelpers
+#else
 @_implementationOnly import COpenCombineHelpers
 #endif
+#endif
 
 // MARK: - zip methods on Publisher
 

Sources/OpenCombineFoundation/Helpers/Locking.swift

@@ -6,8 +6,12 @@
 //
 
 #if canImport(COpenCombineHelpers)
+#if compiler(>=6.0)
+internal import COpenCombineHelpers
+#else
 @_implementationOnly import COpenCombineHelpers
 #endif
+#endif
 
 import OpenCombine
 

Sources/OpenCombineFoundation/OperationQueue+Scheduler.swift

@@ -157,7 +157,7 @@ extension OperationQueue {
         public struct SchedulerOptions {
         }
 
-        private final class DelayReadyOperation: Operation, Cancellable {
+        private final class DelayReadyOperation: Operation, Cancellable, @unchecked Sendable {
 
             fileprivate final class CancellationContext: Cancellable {
                 let lock = UnfairLock.allocate()

Tests/OpenCombineTests/FoundationTests/NotificationCenterTests.swift

@@ -476,7 +476,7 @@ private func makePublisher(
 
 /// A simple mock notification center that always sends notifications to **all**
 /// observers in non-thread safe manner.
-private final class TestNotificationCenter: NotificationCenter {
+private final class TestNotificationCenter: NotificationCenter, @unchecked Sendable {
 
     enum Event {
         case postNotificationWithName(Notification.Name, Any?, [AnyHashable : Any]?)

Tests/OpenCombineTests/FoundationTests/OperationQueueSchedulerTests.swift

@@ -332,7 +332,7 @@ extension OperationQueueScheduler.SchedulerTimeType: DateBackedSchedulerTimeType
 @available(macOS 10.15, iOS 13.0, tvOS 13.0, watchOS 6.0, *)
 extension OperationQueueScheduler: RunLoopLikeScheduler {}
 
-private final class TestOperationQueue: OperationQueue {
+private final class TestOperationQueue: OperationQueue, @unchecked Sendable {
 
     enum Event {
         case progress

Tests/OpenCombineTests/FoundationTests/URLSessionTests.swift

@@ -247,7 +247,7 @@ final class URLSessionTests: XCTestCase {
 
 /// A simple mock URLSession that records its history and allows executing
 /// callbacks synchronously
-private class TestURLSession: URLSession {
+private class TestURLSession: URLSession, @unchecked Sendable {
 
     enum Event: Equatable {
         case delegateQueue
@@ -527,7 +527,7 @@ private class TestURLSession: URLSession {
 #endif // canImport(Darwin) && !os(watchOS)
 }
 
-private final class TestURLSessionDataTask: URLSessionDataTask {
+private final class TestURLSessionDataTask: URLSessionDataTask, @unchecked Sendable {
 
     enum Event: Equatable {
         case taskIdentifier

Tests/OpenCombineTests/Helpers/AssertCrashes.swift

@@ -9,8 +9,12 @@ import Foundation
 import XCTest
 
 #if canImport(COpenCombineHelpers)
+#if compiler(>=6.0)
+internal import COpenCombineHelpers
+#else
 @_implementationOnly import COpenCombineHelpers
 #endif
+#endif
 
 extension XCTest {
 

Tests/OpenCombineTests/ObservableObjectTests.swift

@@ -343,13 +343,13 @@ private final class ObjCClassSubclass: NSObject, ObservableObject {
 }
 
 @available(macOS 10.15, iOS 13.0, tvOS 13.0, watchOS 6.0, *)
-private class ResilientClassSubclass: JSONDecoder, ObservableObject {
+private class ResilientClassSubclass: JSONDecoder, ObservableObject, @unchecked Sendable {
     @Published var published0 = 10
     @Published var published1 = "hello!"
 }
 
 @available(macOS 10.15, iOS 13.0, tvOS 13.0, watchOS 6.0, *)
-private final class ResilientClassSubclass2: ResilientClassSubclass {
+private final class ResilientClassSubclass2: ResilientClassSubclass, @unchecked Sendable {
     @Published var published3 = true
 }
 
@@ -388,7 +388,8 @@ private class NSObjectSubclass: NSObject, ObservableObject {
 @available(macOS 10.15, iOS 13.0, tvOS 13.0, watchOS 6.0, *)
 private class ResilientClassGenericSubclass<Value1, Value2>
     : JSONDecoder,
-      ObservableObject
+      ObservableObject,
+      @unchecked Sendable
 {
     @Published var value1: Value1
     @Published var value2: Value2
@@ -401,7 +402,7 @@ private class ResilientClassGenericSubclass<Value1, Value2>
 
 @available(macOS 10.15, iOS 13.0, tvOS 13.0, watchOS 6.0, *)
 private final class ResilientClassGenericSubclass2<Value1, Value2>
-    : ResilientClassGenericSubclass<Value1, Value2>
+    : ResilientClassGenericSubclass<Value1, Value2>, @unchecked Sendable
 {
     @Published var value3 = false
 }

Tests/OpenCombineTests/PublisherTests/CatchTests.swift

@@ -8,8 +8,12 @@
 import XCTest
 
 #if canImport(COpenCombineHelpers)
+#if compiler(>=6.0)
+internal import COpenCombineHelpers
+#else
 @_implementationOnly import COpenCombineHelpers
 #endif
+#endif
 
 #if OPENCOMBINE_COMPATIBILITY_TEST
 import Combine