NFC: Use mock toolchain for swift-corelib-foundation workaround testing

Author: xedin

Sources/SPMTestSupport/MockBuildTestHelper.swift

@@ -30,7 +30,7 @@ package struct MockToolchain: PackageModel.Toolchain {
     package let swiftCompilerPath = AbsolutePath("/fake/path/to/swiftc")
     package let includeSearchPaths = [AbsolutePath]()
     package let librarySearchPaths = [AbsolutePath]()
-    package let swiftResourcesPath: AbsolutePath? = nil
+    package let swiftResourcesPath: AbsolutePath?
     package let swiftStaticResourcesPath: AbsolutePath? = nil
     package let isSwiftDevelopmentToolchain = false
     package let sdkRootPath: AbsolutePath? = nil
@@ -51,7 +51,9 @@ package struct MockToolchain: PackageModel.Toolchain {
         #endif
     }
 
-    package init() {}
+    package init(swiftResourcesPath: AbsolutePath? = nil) {
+        self.swiftResourcesPath = swiftResourcesPath
+    }
 }
 
 extension Basics.Triple {

Tests/BuildTests/ClangTargetBuildDescriptionTests.swift

@@ -25,22 +25,19 @@ final class ClangTargetBuildDescriptionTests: XCTestCase {
     }
 
     func testSwiftCorelibsFoundationIncludeWorkaround() throws {
-        let macosParameters = mockBuildParameters(
-            toolchain: try UserToolchain.default,
-            targetTriple: .macOS)
-        let linuxParameters = mockBuildParameters(
-            toolchain: try UserToolchain.default,
-            targetTriple: .arm64Linux)
-        let androidParameters = mockBuildParameters(
-            toolchain: try UserToolchain.default,
-            targetTriple: .arm64Android)
+        let toolchain = MockToolchain(swiftResourcesPath: AbsolutePath("/fake/path/lib/swift"))
+
+        let macosParameters = mockBuildParameters(toolchain: toolchain, targetTriple: .macOS)
+        let linuxParameters = mockBuildParameters(toolchain: toolchain, targetTriple: .arm64Linux)
+        let androidParameters = mockBuildParameters(toolchain: toolchain, targetTriple: .arm64Android)
 
         let macDescription = try makeTargetBuildDescription("swift-corelibs-foundation",
                                                             buildParameters: macosParameters)
         XCTAssertFalse(try macDescription.basicArguments().contains("\(macosParameters.toolchain.swiftResourcesPath!)"))
 
         let linuxDescription = try makeTargetBuildDescription("swift-corelibs-foundation",
                                                               buildParameters: linuxParameters)
+        print(try linuxDescription.basicArguments())
         XCTAssertTrue(try linuxDescription.basicArguments().contains("\(linuxParameters.toolchain.swiftResourcesPath!)"))
 
         let androidDescription = try makeTargetBuildDescription("swift-corelibs-foundation",