Tests: Do not use mix of XCTest and Swift Testing

The fixture(..) helper function is being used in XCTest and Swift
Testing tests. However, there was a code path that could lead to calling
XCTFail(), which is a no-op in Swift Testing.

This change rename the functio to fixtureXCTest, and marks it as
deprecated with a note indicating to migrate the test to Swift Testing.
In addition, create a Swift Testing equivalent of the fixture class that
calls the relevant APIs.

Author: bkhouri

Sources/_InternalTestSupport/misc.swift

@@ -28,6 +28,7 @@ import SPMBuildCore
 import struct SPMBuildCore.BuildParameters
 import TSCTestSupport
 import Workspace
+import Testing
 import func XCTest.XCTFail
 import struct XCTest.XCTSkip
 
@@ -112,7 +113,8 @@ public func testWithTemporaryDirectory<Result>(
 /// The temporary copy is deleted after the block returns.  The fixture name may
 /// contain `/` characters, which are treated as path separators, exactly as if
 /// the name were a relative path.
-@discardableResult public func fixture<T>(
+@available(*, deprecated, message: "Migrate test to Swift Testing and use 'fixture' instead")
+@discardableResult public func fixtureXCTest<T>(
     name: String,
     createGitRepo: Bool = true,
     file: StaticString = #file,
@@ -133,7 +135,44 @@ public func testWithTemporaryDirectory<Result>(
                 try? localFileSystem.removeFileTree(tmpDirPath)
             }
 
-            let fixtureDir = try verifyFixtureExists(at: fixtureSubpath, file: file, line: line)
+            let fixtureDir = try verifyFixtureExistsXCTest(at: fixtureSubpath, file: file, line: line)
+            let preparedFixture = try setup(
+                fixtureDir: fixtureDir,
+                in: tmpDirPath,
+                copyName: copyName,
+                createGitRepo:createGitRepo
+            )
+            return try body(preparedFixture)
+        }
+    } catch SwiftPMError.executionFailure(let error, let output, let stderr) {
+        print("**** FAILURE EXECUTING SUBPROCESS ****")
+        print("output:", output)
+        print("stderr:", stderr)
+        throw error
+    }
+}
+
+@discardableResult public func fixture<T>(
+    name: String,
+    createGitRepo: Bool = true,
+    sourceLocation: SourceLocation = #_sourceLocation,
+    body: (AbsolutePath) throws -> T
+) throws -> T {
+    do {
+        // Make a suitable test directory name from the fixture subpath.
+        let fixtureSubpath = try RelativePath(validating: name)
+        let copyName = fixtureSubpath.components.joined(separator: "_")
+
+        // Create a temporary directory for the duration of the block.
+        return try withTemporaryDirectory(prefix: copyName) { tmpDirPath in
+
+            defer {
+                // Unblock and remove the tmp dir on deinit.
+                try? localFileSystem.chmod(.userWritable, path: tmpDirPath, options: [.recursive])
+                try? localFileSystem.removeFileTree(tmpDirPath)
+            }
+
+            let fixtureDir = try verifyFixtureExists(at: fixtureSubpath, sourceLocation: sourceLocation)
             let preparedFixture = try setup(
                 fixtureDir: fixtureDir,
                 in: tmpDirPath,
@@ -154,7 +193,8 @@ public enum TestError: Error {
     case platformNotSupported
 }
 
-@discardableResult public func fixture<T>(
+@available(*, deprecated, message: "Migrate test to Swift Testing and use 'fixture' instead")
+@discardableResult public func fixtureXCTest<T>(
     name: String,
     createGitRepo: Bool = true,
     file: StaticString = #file,
@@ -175,7 +215,7 @@ public enum TestError: Error {
                 try? localFileSystem.removeFileTree(tmpDirPath)
             }
 
-            let fixtureDir = try verifyFixtureExists(at: fixtureSubpath, file: file, line: line)
+            let fixtureDir = try verifyFixtureExistsXCTest(at: fixtureSubpath, file: file, line: line)
             let preparedFixture = try setup(
                 fixtureDir: fixtureDir,
                 in: tmpDirPath,
@@ -192,7 +232,44 @@ public enum TestError: Error {
     }
 }
 
-fileprivate func verifyFixtureExists(at fixtureSubpath: RelativePath, file: StaticString = #file, line: UInt = #line) throws -> AbsolutePath {
+@discardableResult public func fixture<T>(
+    name: String,
+    createGitRepo: Bool = true,
+    sourceLocation: SourceLocation = #_sourceLocation,
+    body: (AbsolutePath) async throws -> T
+) async throws -> T {
+    do {
+        // Make a suitable test directory name from the fixture subpath.
+        let fixtureSubpath = try RelativePath(validating: name)
+        let copyName = fixtureSubpath.components.joined(separator: "_")
+
+        // Create a temporary directory for the duration of the block.
+        return try await withTemporaryDirectory(prefix: copyName) { tmpDirPath in
+
+            defer {
+                // Unblock and remove the tmp dir on deinit.
+                try? localFileSystem.chmod(.userWritable, path: tmpDirPath, options: [.recursive])
+                try? localFileSystem.removeFileTree(tmpDirPath)
+            }
+
+            let fixtureDir = try verifyFixtureExists(at: fixtureSubpath, sourceLocation: sourceLocation)
+            let preparedFixture = try setup(
+                fixtureDir: fixtureDir,
+                in: tmpDirPath,
+                copyName: copyName,
+                createGitRepo:createGitRepo
+            )
+            return try await body(preparedFixture)
+        }
+    } catch SwiftPMError.executionFailure(let error, let output, let stderr) {
+        print("**** FAILURE EXECUTING SUBPROCESS ****")
+        print("output:", output)
+        print("stderr:", stderr)
+        throw error
+    }
+}
+
+fileprivate func verifyFixtureExistsXCTest(at fixtureSubpath: RelativePath, file: StaticString = #file, line: UInt = #line) throws -> AbsolutePath {
     let fixtureDir = AbsolutePath("../../../Fixtures", relativeTo: #file)
         .appending(fixtureSubpath)
 
@@ -205,6 +282,19 @@ fileprivate func verifyFixtureExists(at fixtureSubpath: RelativePath, file: Stat
     return fixtureDir
 }
 
+fileprivate func verifyFixtureExists(at fixtureSubpath: RelativePath, sourceLocation: SourceLocation = #_sourceLocation) throws -> AbsolutePath {
+    let fixtureDir = AbsolutePath("../../../Fixtures", relativeTo: #file)
+        .appending(fixtureSubpath)
+
+    // Check that the fixture is really there.
+    guard localFileSystem.isDirectory(fixtureDir) else {
+        Issue.record("No such fixture: \(fixtureDir)", sourceLocation: sourceLocation)
+        throw SwiftPMError.packagePathNotFound
+    }
+
+    return fixtureDir
+}
+
 fileprivate func setup(
     fixtureDir: AbsolutePath,
     in tmpDirPath: AbsolutePath,

Tests/BuildTests/BuildPlanTests.swift

@@ -628,7 +628,7 @@ class BuildPlanTestCase: BuildSystemProviderTestCase {
             toolchain: UserToolchain.default,
             fileSystem: localFileSystem
         )
-        try await fixture(name: "Miscellaneous/PackageNameFlag") { fixturePath in
+        try await fixtureXCTest(name: "Miscellaneous/PackageNameFlag") { fixturePath in
             let (stdout, stderr) = try await executeSwiftBuild(
                 fixturePath.appending("appPkg"),
                 extraArgs: ["--vv"],
@@ -666,7 +666,7 @@ class BuildPlanTestCase: BuildSystemProviderTestCase {
             toolchain: UserToolchain.default,
             fileSystem: localFileSystem
         )
-        try await fixture(name: "Miscellaneous/PackageNameFlag") { fixturePath in
+        try await fixtureXCTest(name: "Miscellaneous/PackageNameFlag") { fixturePath in
             let (stdout, _) = try await executeSwiftBuild(
                 fixturePath.appending("appPkg"),
                 extraArgs: ["--vv"],
@@ -697,7 +697,7 @@ class BuildPlanTestCase: BuildSystemProviderTestCase {
             toolchain: UserToolchain.default,
             fileSystem: localFileSystem
         )
-        try await fixture(name: "Miscellaneous/TargetPackageAccess") { fixturePath in
+        try await fixtureXCTest(name: "Miscellaneous/TargetPackageAccess") { fixturePath in
             let (stdout, _) = try await executeSwiftBuild(
                 fixturePath.appending("libPkg"),
                 extraArgs: ["-v"],

Tests/BuildTests/BuildSystemDelegateTests.swift

@@ -19,7 +19,7 @@ import var TSCBasic.localFileSystem
 final class BuildSystemDelegateTests: XCTestCase {
     func testDoNotFilterLinkerDiagnostics() async throws {
         try XCTSkipIf(!UserToolchain.default.supportsSDKDependentTests(), "skipping because test environment doesn't support this test")
-        try await fixture(name: "Miscellaneous/DoNotFilterLinkerDiagnostics") { fixturePath in
+        try await fixtureXCTest(name: "Miscellaneous/DoNotFilterLinkerDiagnostics") { fixturePath in
             #if !os(macOS)
             // These linker diagnostics are only produced on macOS.
             try XCTSkipIf(true, "test is only supported on macOS")
@@ -39,7 +39,7 @@ final class BuildSystemDelegateTests: XCTestCase {
         #else
         let executableExt = ""
         #endif
-        try await fixture(name: "Miscellaneous/TestableExe") { fixturePath in
+        try await fixtureXCTest(name: "Miscellaneous/TestableExe") { fixturePath in
             _ = try await executeSwiftBuild(fixturePath)
             let execPath = fixturePath.appending(components: ".build", "debug", "TestableExe1\(executableExt)")
             XCTAssertTrue(localFileSystem.exists(execPath), "executable not found at '\(execPath)'")

Tests/BuildTests/IncrementalBuildTests.swift

@@ -40,7 +40,7 @@ final class IncrementalBuildTests: XCTestCase {
 
     func testIncrementalSingleModuleCLibraryInSources() async throws {
         try XCTSkipIf(!UserToolchain.default.supportsSDKDependentTests(), "skipping because test environment doesn't support this test")
-        try await fixture(name: "CFamilyTargets/CLibrarySources") { fixturePath in
+        try await fixtureXCTest(name: "CFamilyTargets/CLibrarySources") { fixturePath in
             // Build it once and capture the log (this will be a full build).
             let (fullLog, _) = try await executeSwiftBuild(fixturePath)
 
@@ -98,7 +98,7 @@ final class IncrementalBuildTests: XCTestCase {
 
     func testBuildManifestCaching() async throws {
         try XCTSkipIf(!UserToolchain.default.supportsSDKDependentTests(), "skipping because test environment doesn't support this test")
-        try await fixture(name: "ValidLayouts/SingleModule/Library") { fixturePath in
+        try await fixtureXCTest(name: "ValidLayouts/SingleModule/Library") { fixturePath in
             @discardableResult
             func build() async throws -> String {
                 return try await executeSwiftBuild(fixturePath).stdout
@@ -132,7 +132,7 @@ final class IncrementalBuildTests: XCTestCase {
 
     func testDisableBuildManifestCaching() async throws {
         try XCTSkipIf(!UserToolchain.default.supportsSDKDependentTests(), "skipping because test environment doesn't support this test")
-        try await fixture(name: "ValidLayouts/SingleModule/Library") { fixturePath in
+        try await fixtureXCTest(name: "ValidLayouts/SingleModule/Library") { fixturePath in
             @discardableResult
             func build() async throws -> String {
                 return try await executeSwiftBuild(fixturePath, extraArgs: ["--disable-build-manifest-caching"]).stdout
@@ -152,7 +152,7 @@ final class IncrementalBuildTests: XCTestCase {
 #if os(macOS)
         try XCTSkipIf(!UserToolchain.default.supportsSDKDependentTests(), "skipping because test environment doesn't support this test")
 
-        try await fixture(name: "ValidLayouts/SingleModule/Library") { fixturePath in
+        try await fixtureXCTest(name: "ValidLayouts/SingleModule/Library") { fixturePath in
             let dummySwiftcPath = SwiftPM.xctestBinaryPath(for: "dummy-swiftc")
             let swiftCompilerPath = try UserToolchain.default.swiftCompilerPath
             let environment: Environment = [

Tests/BuildTests/PluginsBuildPlanTests.swift

@@ -20,7 +20,7 @@ final class PluginsBuildPlanTests: XCTestCase {
     func testBuildToolsDatabasePath() async throws {
         try XCTSkipOnWindows(because: "Fails to build the project to due to incorrect Path handling.  Possibly related to https://github.com/swiftlang/swift-package-manager/issues/8511")
 
-        try await fixture(name: "Miscellaneous/Plugins/MySourceGenPlugin") { fixturePath in
+        try await fixtureXCTest(name: "Miscellaneous/Plugins/MySourceGenPlugin") { fixturePath in
             let (stdout, _) = try await executeSwiftBuild(fixturePath)
             XCTAssertMatch(stdout, .contains("Build complete!"))
             // FIXME: This is temporary until build of plugin tools is extracted into its own command.
@@ -48,7 +48,7 @@ final class PluginsBuildPlanTests: XCTestCase {
         let targetTriple = hostToolchain.targetTriple.arch == .aarch64 ? x86Triple : armTriple
 
         // By default, plugin dependencies are built for the host platform
-        try await fixture(name: "Miscellaneous/Plugins/CommandPluginTestStub") { fixturePath in
+        try await fixtureXCTest(name: "Miscellaneous/Plugins/CommandPluginTestStub") { fixturePath in
             let (stdout, stderr) = try await executeSwiftPackage(fixturePath, extraArgs: ["-v", "build-plugin-dependency"])
             XCTAssertMatch(stdout, .contains("Hello from dependencies-stub"))
             XCTAssertMatch(stderr, .contains("Build of product 'plugintool' complete!"))
@@ -65,7 +65,7 @@ final class PluginsBuildPlanTests: XCTestCase {
         }
 
         // When cross compiling the final product, plugin dependencies should still be built for the host
-        try await fixture(name: "Miscellaneous/Plugins/CommandPluginTestStub") { fixturePath in
+        try await fixtureXCTest(name: "Miscellaneous/Plugins/CommandPluginTestStub") { fixturePath in
             let (stdout, stderr) = try await executeSwiftPackage(fixturePath, extraArgs: ["--triple", targetTriple, "-v", "build-plugin-dependency"])
             XCTAssertMatch(stdout, .contains("Hello from dependencies-stub"))
             XCTAssertMatch(stderr, .contains("Build of product 'plugintool' complete!"))