Add tests for SwiftHeaderToolTaskAction.

Tests/SWBTaskExecutionTests/SwiftHeaderToolTaskActionTests.swift

@@ -0,0 +1,138 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift open source project
+//
+// Copyright (c) 2025 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See http://swift.org/LICENSE.txt for license information
+// See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+import Testing
+import SWBUtil
+import SWBTestSupport
+import SWBTaskExecution
+
+struct SwiftHeaderToolTaskActionTests: CoreBasedTests {
+
+    /// Utility function to create and run a `SwiftHeaderToolTaskAction` and call a block to check the results.
+    private func testSwiftHeaderToolTaskAction(archs: [String], validate: (ByteString) -> Void) async throws {
+        guard !archs.isEmpty else {
+            Issue.record("Must pass at least one architecture.")
+            return
+        }
+
+        let fs = PseudoFS()
+
+        let inputDir = Path.root.join("Volumes/Inputs")
+        let outputDir = Path.root.join("Volumes/Outputs")
+
+        // Build the command line and write the input files.
+        try fs.createDirectory(inputDir, recursive: true)
+        try fs.createDirectory(outputDir, recursive: true)
+        var commandLine = ["builtin-swiftHeaderTool"]
+        if archs.count == 1 {
+            commandLine.append("-single")
+        }
+        for arch in archs {
+            let inputPath = inputDir.join("\(arch)/GeneratedHeader-Swift.h")
+            try await fs.writeFileContents(inputPath) { stream in
+                stream <<< "Contents of file for \(arch)\n"
+            }
+            commandLine.append(contentsOf: [
+                "-arch", arch,
+                inputPath.str,
+            ])
+        }
+        let outputPath = outputDir.join("GeneratedHeader-Swift.h")
+        commandLine.append(contentsOf: [
+            "-o", outputPath.str
+        ])
+
+        // Construct and run the task action.
+        let executionDelegate = MockExecutionDelegate(fs: fs)
+        let outputDelegate = MockTaskOutputDelegate()
+        let action = SwiftHeaderToolTaskAction()
+        let task = Task(forTarget: nil, ruleInfo: [], commandLine: commandLine, workingDirectory: .root, outputs: [], action: action, execDescription: "")
+        guard let result = await task.action?.performTaskAction(task, dynamicExecutionDelegate: MockDynamicTaskExecutionDelegate(), executionDelegate: executionDelegate, clientDelegate: MockTaskExecutionClientDelegate(), outputDelegate: outputDelegate) else {
+            Issue.record("No result was returned.")
+            return
+        }
+
+        // Check the command succeeded with no errors.
+        #expect(result == .succeeded)
+        #expect(outputDelegate.messages == [])
+
+        // Read the output file and pass it to the validation block.
+        let outputFileContents = try fs.read(outputPath)
+        validate(outputFileContents)
+    }
+
+    /// Test that running the tool for a single arch just copies the file and doesn't add any `#if` blocks.
+    @Test
+    func testSingleArch() async throws {
+        let archs = ["arm64"]
+        try await testSwiftHeaderToolTaskAction(archs: archs) { outputFileContents in
+            let expectedFileContents =
+                "Contents of file for arm64\n"
+            #expect(outputFileContents == expectedFileContents)
+        }
+    }
+
+    /// Basic test for two architectures.
+    @Test
+    func testTwoArchs() async throws {
+        let archs = ["arm64", "x86_64"]
+        try await testSwiftHeaderToolTaskAction(archs: archs) { outputFileContents in
+            let expectedFileContents =
+                "#if 0\n" +
+                "#elif defined(__arm64__) && __arm64__\n" +
+                "Contents of file for arm64\n\n" +
+                "#elif defined(__x86_64__) && __x86_64__\n" +
+                "Contents of file for x86_64\n\n" +
+                "#else\n" +
+                "#error unsupported Swift architecture\n" +
+                "#endif\n"
+            #expect(outputFileContents == expectedFileContents)
+        }
+    }
+
+    /// Test that when building for `arm64e` but not `arm64` that we guard the `arm64e` file contents by the fallback `arm64` macro.
+    @Test
+    func testFallbackArch() async throws {
+        let archs = ["arm64e", "x86_64"]
+        try await testSwiftHeaderToolTaskAction(archs: archs) { outputFileContents in
+            let expectedFileContents =
+                "#if 0\n" +
+                "#elif defined(__arm64__) && __arm64__\n" +
+                "Contents of file for arm64e\n\n" +
+                "#elif defined(__x86_64__) && __x86_64__\n" +
+                "Contents of file for x86_64\n\n" +
+                "#else\n" +
+                "#error unsupported Swift architecture\n" +
+                "#endif\n"
+            #expect(outputFileContents == expectedFileContents)
+        }
+    }
+
+    /// Test that when building for both `arm64e` and `arm64` that we end up with the content for both archs using both macros.
+    @Test
+    func testNoFallbackArch() async throws {
+        let archs = ["arm64", "arm64e"]
+        try await testSwiftHeaderToolTaskAction(archs: archs) { outputFileContents in
+            let expectedFileContents =
+                "#if 0\n" +
+                "#elif defined(__arm64e__) && __arm64e__\n" +
+                "Contents of file for arm64e\n\n" +
+                "#elif defined(__arm64__) && __arm64__\n" +
+                "Contents of file for arm64\n\n" +
+                "#else\n" +
+                "#error unsupported Swift architecture\n" +
+                "#endif\n"
+            #expect(outputFileContents == expectedFileContents)
+        }
+    }
+
+}