Add Swift 6.0 to Linux test matrix

.github/workflows/ci.yml

@@ -59,6 +59,7 @@ jobs:
       matrix:
         swift:
           - '5.10'
+          - '6.0'
     name: Ubuntu (Swift ${{ matrix.swift }})
     runs-on: ubuntu-latest
     container: swift:${{ matrix.swift }}

Sources/Dependencies/DependencyValues.swift

@@ -149,7 +149,7 @@ public struct DependencyValues: Sendable {
             .takeUnretainedValue()
         else { return }
         let testCaseWillStartBlock: @convention(block) (AnyObject) -> Void = { _ in
-          DependencyValues._current.cachedValues.cached = [:]
+          DependencyValues._current.cachedValues.resetCache()
         }
         let testCaseWillStartImp = imp_implementationWithBlock(testCaseWillStartBlock)
         class_addMethod(
@@ -167,7 +167,7 @@ public struct DependencyValues: Sendable {
       if isTesting {
         XCTestObservationCenter.shared.addTestObserver(
           TestObserver {
-            DependencyValues._current.cachedValues.cached = [:]
+            DependencyValues._current.cachedValues.resetCache()
           }
         )
       }
@@ -191,7 +191,7 @@ public struct DependencyValues: Sendable {
         }
       #endif
       pRegisterTestObserver?({
-        DependencyValues._current.cachedValues.cached = [:]
+        DependencyValues._current.cachedValues.resetCache()
       })
     #endif
   }
@@ -286,6 +286,8 @@ public struct DependencyValues: Sendable {
           reportIssue("Ignoring dependencies prepared in preview app entry point")
           return
         }
+        cachedValues.lock.lock()
+        defer { cachedValues.lock.unlock() }
         let cacheKey = CachedValues.CacheKey(id: TypeIdentifier(key), context: context)
         guard !cachedValues.cached.keys.contains(cacheKey) else {
           if cachedValues.cached[cacheKey]?.preparationID != DependencyValues.preparationID {
@@ -405,7 +407,7 @@ public struct DependencyValues: Sendable {
     message: "'resetCache' is no longer necessary for most (unparameterized) '@Test' cases"
   )
   public func resetCache() {
-    cachedValues.cached = [:]
+    cachedValues.resetCache()
   }
 }
 
@@ -478,9 +480,15 @@ public final class CachedValues: @unchecked Sendable {
     let preparationID: UUID?
   }
 
-  private let lock = NSRecursiveLock()
+  public let lock = NSRecursiveLock()
   public var cached = [CacheKey: CachedValue]()
 
+  public func resetCache() {
+    lock.lock()
+    defer { lock.unlock() }
+    cached = [:]
+  }
+
   func value<Key: TestDependencyKey>(
     for key: Key.Type,
     context: DependencyContext,

Tests/DependenciesTests/CacheTests.swift

@@ -5,7 +5,7 @@ final class CachedValueTests: XCTestCase {
   override func tearDown() {
     super.tearDown()
     CacheLocals.$skipFailure.withValue(true) {
-      DependencyValues._current.cachedValues.cached = [:]
+      DependencyValues._current.cachedValues.resetCache()
     }
   }
 

Tests/DependenciesTests/DependencyValuesTests.swift

@@ -437,30 +437,33 @@ final class DependencyValuesTests: XCTestCase {
       self.wait(for: [expectation], timeout: 1)
     }
 
-    @MainActor
-    func testEscapingInFeatureModel_InstanceVariablePropagated() async {
-      let expectation = self.expectation(description: "escape")
-
+    // TODO: Remove this condition when Linux CI is updated to a more recent Swift 6.
+    #if !os(Linux) || compiler(<6)
       @MainActor
-      class FeatureModel /*: ObservableObject*/ {
-        @Dependency(\.fullDependency) var fullDependency
-        func doSomething(expectation: XCTestExpectation) {
-          DispatchQueue.main.async {
-            XCTAssertEqual(self.fullDependency.value, 42)
-            expectation.fulfill()
+      func testEscapingInFeatureModel_InstanceVariablePropagated() async {
+        let expectation = self.expectation(description: "escape")
+
+        @MainActor
+        class FeatureModel /*: ObservableObject*/ {
+          @Dependency(\.fullDependency) var fullDependency
+          func doSomething(expectation: XCTestExpectation) {
+            DispatchQueue.main.async {
+              XCTAssertEqual(self.fullDependency.value, 42)
+              expectation.fulfill()
+            }
           }
         }
-      }
 
-      let model = withDependencies {
-        $0.fullDependency.value = 42
-      } operation: {
-        FeatureModel()
-      }
+        let model = withDependencies {
+          $0.fullDependency.value = 42
+        } operation: {
+          FeatureModel()
+        }
 
-      model.doSomething(expectation: expectation)
-      await fulfillment(of: [expectation], timeout: 1)
-    }
+        model.doSomething(expectation: expectation)
+        await fulfillment(of: [expectation], timeout: 1)
+      }
+    #endif
 
     func testEscapingInFeatureModel_NotPropagated() async {
       let expectation = self.expectation(description: "escape")