Tests: Convert Basics/FileSystem/* to Swift Testing

Convert test from XCTest to Swift Testing.
  - Tests/BasicsTests/FileSystem/FileSystemTests.swift
  - Tests/BasicsTests/FileSystem/PathShimTests.swift
  - Tests/BasicsTests/FileSystem/PathTests.swift
  - Tests/BasicsTests/FileSystem/TemporaryFileTests.swift
  - Tests/BasicsTests/FileSystem/VFSTests.swift

relates to: #8433

Author: bkhouri

Sources/_InternalTestSupport/Process.swift

@@ -0,0 +1,43 @@
+/*
+ This source file is part of the Swift.org open source project
+
+ Copyright (c) 2014 - 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 Swift project authors
+ */
+
+public import Foundation
+
+public enum OperatingSystem: Hashable, Sendable {
+    case macOS
+    case windows
+    case linux
+    case android
+    case unknown
+}
+
+extension ProcessInfo {
+    #if os(macOS)
+    public static let hostOperatingSystem = OperatingSystem.macOS
+    #elseif os(Linux)
+    public static let hostOperatingSystem = OperatingSystem.linux
+    #elseif os(Windows)
+    public static let hostOperatingSystem = OperatingSystem.windows
+    #else
+    public static let hostOperatingSystem = OperatingSystem.unknown
+    #endif
+
+    #if os(Windows)
+    public static let EOL = "\r\n"
+    #else
+    public static let EOL = "\n"
+    #endif
+
+    #if os(Windows)
+    public static let exeSuffix = ".exe"
+    #else
+    public static let exeSuffix = ""
+    #endif
+}

Sources/_InternalTestSupport/SkippedTestSupport.swift

@@ -0,0 +1,70 @@
+
+/*
+ This source file is part of the Swift.org open source project
+
+ Copyright (c) 2014 - 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 Swift project authors
+ */
+
+import class Foundation.FileManager
+import class Foundation.ProcessInfo
+import Testing
+
+extension Trait where Self == Testing.ConditionTrait {
+    /// Skip test if the host operating system does not match the running OS.
+    public static func requireHostOS(_ os: OperatingSystem, when condition: Bool = true, sourceLocation: SourceLocation = #_sourceLocation) -> Self {
+        enabled("This test requires a \(os) host OS.", sourceLocation: sourceLocation) {
+            ProcessInfo.hostOperatingSystem == os && condition
+        }
+    }
+
+    /// Skip test if the host operating system matches the running OS.
+    public static func skipHostOS(_ os: OperatingSystem, _ comment: Comment? = nil, sourceLocation: SourceLocation = #_sourceLocation) -> Self {
+        disabled(comment ?? "This test cannot run on a \(os) host OS.", sourceLocation: sourceLocation) {
+            ProcessInfo.hostOperatingSystem == os
+        }
+    }
+
+    /// Skip test unconditionally
+    public static func skip(_ comment: Comment? = nil, sourceLocation: SourceLocation = #_sourceLocation) -> Self {
+        disabled(comment ?? "Unconditional skip, a comment should be added for the reason", sourceLocation: sourceLocation) { true }
+    }
+
+    /// Skip test if the environment is self hosted.
+    public static func skipSwiftCISelfHosted(_ comment: Comment? = nil, sourceLocation: SourceLocation = #_sourceLocation) -> Self {
+        disabled(comment ?? "SwiftCI is self hosted", sourceLocation: sourceLocation) {
+            ProcessInfo.processInfo.environment["SWIFTCI_IS_SELF_HOSTED"] != nil
+        }
+    }
+
+    /// Skip test if the test environment has a restricted network access, i.e. cannot get to internet.
+    public static func requireUnrestrictedNetworkAccess(_ comment: Comment? = nil, sourceLocation: SourceLocation = #_sourceLocation) -> Self {
+        disabled(comment ?? "CI Environment has restricted network access", sourceLocation: sourceLocation) {
+            ProcessInfo.processInfo.environment["SWIFTCI_RESTRICTED_NETWORK_ACCESS"] != nil
+        }
+    }
+
+    /// Skip test if built by XCode.
+    public static func skipIfXcodeBuilt(sourceLocation: SourceLocation = #_sourceLocation) -> Self {
+        disabled("Tests built by Xcode", sourceLocation: sourceLocation) {
+            #if Xcode
+            true
+            #else
+            false
+            #endif
+        }
+    }
+
+    /// Constructs a condition trait that causes a test to be disabled if the Foundation process spawning implementation
+    /// is not using `posix_spawn_file_actions_addchdir`.
+    public static var requireThreadSafeWorkingDirectory: Self {
+        disabled("Thread-safe process working directory support is unavailable.") {
+            // Amazon Linux 2 has glibc 2.26, and glibc 2.29 is needed for posix_spawn_file_actions_addchdir_np support
+            FileManager.default.contents(atPath: "/etc/system-release")
+                .map { String(decoding: $0, as: UTF8.self) == "Amazon Linux release 2 (Karoo)\n" } ?? false
+        }
+    }
+}

Tests/BasicsTests/FileSystem/FileSystemTests.swift

@@ -9,13 +9,13 @@
 // See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
 //
 //===----------------------------------------------------------------------===//
-
 @testable import Basics
 import TSCTestSupport
-import XCTest
+import Testing
 
-final class FileSystemTests: XCTestCase {
-    func testStripFirstLevelComponent() throws {
+struct FileSystemTests {
+    @Test
+    func stripFirstLevelComponent() throws {
         let fileSystem = InMemoryFileSystem()
 
         let rootPath = AbsolutePath("/root")
@@ -35,29 +35,31 @@ final class FileSystemTests: XCTestCase {
 
         do {
             let contents = try fileSystem.getDirectoryContents(.root)
-            XCTAssertEqual(contents.count, 1)
+            #expect(contents.count == 1)
         }
 
         try fileSystem.stripFirstLevel(of: .root)
 
         do {
             let contents = Set(try fileSystem.getDirectoryContents(.root))
-            XCTAssertEqual(contents.count, totalDirectories + totalFiles)
+            #expect(contents.count == totalDirectories + totalFiles)
 
             for index in 0 ..< totalDirectories {
-                XCTAssertTrue(contents.contains("dir\(index)"))
+                #expect(contents.contains("dir\(index)"))
             }
             for index in 0 ..< totalFiles {
-                XCTAssertTrue(contents.contains("file\(index)"))
+                #expect(contents.contains("file\(index)"))
             }
         }
     }
 
-    func testStripFirstLevelComponentErrors() throws {
+    @Test
+    func stripFirstLevelComponentErrors() throws {
+        let functionUnderTest = "stripFirstLevel"
         do {
             let fileSystem = InMemoryFileSystem()
-            XCTAssertThrowsError(try fileSystem.stripFirstLevel(of: .root), "expected error") { error in
-                XCTAssertMatch((error as? StringError)?.description, .contains("requires single top level directory"))
+            #expect(throws: StringError("\(functionUnderTest) requires single top level directory")) {
+                try fileSystem.stripFirstLevel(of: .root)
             }
         }
 
@@ -67,8 +69,8 @@ final class FileSystemTests: XCTestCase {
                 let path = AbsolutePath.root.appending("dir\(index)")
                 try fileSystem.createDirectory(path, recursive: false)
             }
-            XCTAssertThrowsError(try fileSystem.stripFirstLevel(of: .root), "expected error") { error in
-                XCTAssertMatch((error as? StringError)?.description, .contains("requires single top level directory"))
+            #expect(throws: StringError("\(functionUnderTest) requires single top level directory")) {
+                try fileSystem.stripFirstLevel(of: .root)
             }
         }
 
@@ -78,17 +80,17 @@ final class FileSystemTests: XCTestCase {
                 let path = AbsolutePath.root.appending("file\(index)")
                 try fileSystem.writeFileContents(path, string: "\(index)")
             }
-            XCTAssertThrowsError(try fileSystem.stripFirstLevel(of: .root), "expected error") { error in
-                XCTAssertMatch((error as? StringError)?.description, .contains("requires single top level directory"))
+            #expect(throws: StringError("\(functionUnderTest) requires single top level directory")) {
+                try fileSystem.stripFirstLevel(of: .root)
             }
         }
 
         do {
             let fileSystem = InMemoryFileSystem()
             let path = AbsolutePath.root.appending("file")
             try fileSystem.writeFileContents(path, string: "")
-            XCTAssertThrowsError(try fileSystem.stripFirstLevel(of: .root), "expected error") { error in
-                XCTAssertMatch((error as? StringError)?.description, .contains("requires single top level directory"))
+            #expect(throws: StringError("\(functionUnderTest) requires single top level directory")) {
+                try fileSystem.stripFirstLevel(of: .root)
             }
         }
     }

Tests/BasicsTests/FileSystem/PathShimTests.swift

@@ -12,64 +12,65 @@
 
 import Basics
 import Foundation
-import XCTest
+import Testing
 
-class PathShimTests: XCTestCase {
-    func testRescursiveDirectoryCreation() {
-        // For the tests we'll need a temporary directory.
+struct PathShimTests {
+    @Test
+    func rescursiveDirectoryCreation() {
         try! withTemporaryDirectory(removeTreeOnDeinit: true) { path in
             // Create a directory under several ancestor directories.
             let dirPath = path.appending(components: "abc", "def", "ghi", "mno", "pqr")
             try! makeDirectories(dirPath)
 
             // Check that we were able to actually create the directory.
-            XCTAssertTrue(localFileSystem.isDirectory(dirPath))
+            #expect(localFileSystem.isDirectory(dirPath))
 
             // Check that there's no error if we try to create the directory again.
-            try! makeDirectories(dirPath)
+            #expect(throws: Never.self) {
+                try! makeDirectories(dirPath)
+            }
         }
     }
 }
 
-class WalkTests: XCTestCase {
-    func testNonRecursive() throws {
-        #if os(Android)
+struct WalkTests {
+    @Test
+    func nonRecursive() throws {
+#if os(Android)
         let root = "/system"
         var expected: [AbsolutePath] = [
             "\(root)/usr",
             "\(root)/bin",
             "\(root)/etc",
         ]
-        #elseif os(Windows)
+        let expectedCount = 3
+#elseif os(Windows)
         let root = ProcessInfo.processInfo.environment["SystemRoot"]!
         var expected: [AbsolutePath] = [
             "\(root)/System32",
             "\(root)/SysWOW64",
         ]
-        #else
+        let expectedCount = (root as NSString).pathComponents.count + 2
+#else
         let root = ""
         var expected: [AbsolutePath] = [
             "/usr",
             "/bin",
             "/sbin",
         ]
-        #endif
+        let expectedCount = 2
+#endif
         for x in try walk(AbsolutePath(validating: "\(root)/"), recursively: false) {
             if let i = expected.firstIndex(of: x) {
                 expected.remove(at: i)
             }
-            #if os(Android)
-            XCTAssertEqual(3, x.components.count)
-            #elseif os(Windows)
-            XCTAssertEqual((root as NSString).pathComponents.count + 2, x.components.count)
-            #else
-            XCTAssertEqual(2, x.components.count)
-            #endif
+            #expect(x.components.count == expectedCount, "Actual is not as expected")
         }
-        XCTAssertEqual(expected.count, 0)
+        #expect(expected.count == 0)
     }
 
-    func testRecursive() {
+    @Test
+    func recursive() {
         let root = AbsolutePath(#file).parentDirectory.parentDirectory.parentDirectory.parentDirectory
             .appending(component: "Sources")
         var expected = [
@@ -82,6 +83,6 @@ class WalkTests: XCTestCase {
                 expected.remove(at: i)
             }
         }
-        XCTAssertEqual(expected, [])
+        #expect(expected == [])
     }
 }