Fix dependency test trait for stateful dependencies. (#314)

* Fix dependency test trait for stateful dependencies.

* fix older platforms

Sources/DependenciesTestSupport/TestTrait.swift

@@ -43,10 +43,10 @@
     ///   - value: A dependency value to override for the test.
     public static func dependency<Value>(
       _ keyPath: WritableKeyPath<DependencyValues, Value> & Sendable,
-      _ value: sending Value
+      _ value: @autoclosure @escaping @Sendable () -> Value
     ) -> Self {
-      Self { [uncheckedValue = UncheckedSendable(value)] in
-        $0[keyPath: keyPath] = uncheckedValue.wrappedValue
+      Self {
+        $0[keyPath: keyPath] = value()
       }
     }
 
@@ -79,9 +79,9 @@
     ///   - keyPath: A key path to a dependency value.
     ///   - value: A dependency value to override for the test.
     public static func dependency<Value: TestDependencyKey>(
-      _ value: Value
+      _ value: @autoclosure @escaping @Sendable () -> Value
     ) -> Self where Value == Value.Value {
-      Self { $0[Value.self] = value }
+      Self { $0[Value.self] = value() }
     }
 
     /// A trait that overrides a test's or suite's dependencies.

Tests/DependenciesTests/TestTraitTests.swift

@@ -0,0 +1,32 @@
+#if canImport(Testing)
+  import Dependencies
+  import DependenciesTestSupport
+  import Foundation
+  import Testing
+
+  @Suite(.dependency(\.uuid, .incrementing))
+  struct TestTraitTests {
+    @Dependency(\.uuid) var uuid
+
+    @Test func statefulDependency1() async throws {
+      for index in 0...100 {
+        #expect(uuid() == UUID(index))
+        try await Task.sleep(for: .milliseconds(1))
+      }
+    }
+
+    @Test func statefulDependency2() async throws {
+      for index in 0...100 {
+        #expect(uuid() == UUID(index))
+        try await Task.sleep(for: .milliseconds(1))
+      }
+    }
+
+    @Test func statefulDependency3() async throws {
+      for index in 0...100 {
+        #expect(uuid() == UUID(index))
+        try await Task.sleep(for: .milliseconds(1))
+      }
+    }
+  }
+#endif