FoundationEssentials: fix up linkOrCopyFile on Windows (#675)

Adjust the Windows path for copying (or linking) files. This adds the
missing recursion in the copy (the documentation for `CopyFile2` was not
clear that the recursive copy is not performed).

Author: compnerd

Sources/FoundationEssentials/FileManager/FileOperations.swift

@@ -799,20 +799,32 @@ enum _FileOperations {
                 throw CocoaError.fileOperationError(.fileReadNoSuchFile, src, dst, variant: bCopyFile ? "Copy" : "Link")
             }
 
+            guard delegate.shouldPerformOnItemAtPath(src, to: dst) else { return }
+
             try dst.withNTPathRepresentation { pwszDestination in
-                if bCopyFile || faAttributes.dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT == FILE_ATTRIBUTE_REPARSE_POINT {
+                if faAttributes.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY == FILE_ATTRIBUTE_DIRECTORY {
+                    do {
+                        try fileManager.createDirectory(atPath: dst, withIntermediateDirectories: true)
+                    } catch {
+                        try delegate.throwIfNecessary(error, src, dst)
+                    }
+                    for item in _Win32DirectoryContentsSequence(path: src, appendSlashForDirectory: true) {
+                        try linkOrCopyFile(src.appendingPathComponent(item.fileName), dst: dst.appendingPathComponent(item.fileName), with: fileManager, delegate: delegate)
+                    }
+                } else if bCopyFile || faAttributes.dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT == FILE_ATTRIBUTE_REPARSE_POINT {
                     var ExtendedParameters: COPYFILE2_EXTENDED_PARAMETERS = .init()
                     ExtendedParameters.dwSize = DWORD(MemoryLayout<COPYFILE2_EXTENDED_PARAMETERS>.size)
-                    ExtendedParameters.dwCopyFlags = COPY_FILE_COPY_SYMLINK | COPY_FILE_NO_BUFFERING | COPY_FILE_OPEN_AND_COPY_REPARSE_POINT
-                    if faAttributes.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY == FILE_ATTRIBUTE_DIRECTORY {
-                        ExtendedParameters.dwCopyFlags |= COPY_FILE_DIRECTORY
-                    }
+                    ExtendedParameters.dwCopyFlags = COPY_FILE_FAIL_IF_EXISTS | COPY_FILE_COPY_SYMLINK | COPY_FILE_NO_BUFFERING | COPY_FILE_OPEN_AND_COPY_REPARSE_POINT
 
-                    guard SUCCEEDED(CopyFile2(pwszSource, pwszDestination, &ExtendedParameters)) else {
-                        throw CocoaError.copyFileError(GetLastError(), src, dst)
+                    if FAILED(CopyFile2(pwszSource, pwszDestination, &ExtendedParameters)) {
+                        try delegate.throwIfNecessary(GetLastError(), src, dst)
                     }
                 } else {
-                    try fileManager.createSymbolicLink(atPath: dst, withDestinationPath: src)
+                    do {
+                        try fileManager.createSymbolicLink(atPath: dst, withDestinationPath: src)
+                    } catch {
+                        try delegate.throwIfNecessary(error, src, dst)
+                    }
                 }
             }
         }

Sources/FoundationEssentials/WinSDK+Extensions.swift

@@ -13,6 +13,10 @@
 
 import WinSDK
 
+package var COPY_FILE_FAIL_IF_EXISTS: DWORD {
+    DWORD(WinSDK.COPY_FILE_FAIL_IF_EXISTS)
+}
+
 package var COPY_FILE_COPY_SYMLINK: DWORD {
     DWORD(WinSDK.COPY_FILE_COPY_SYMLINK)
 }
@@ -249,6 +253,11 @@ package func PathAllocCombine(_ pszPathIn: String, _ pszMore: String, _ dwFlags:
     }
 }
 
+@inline(__always)
+package func FAILED(_ hr: HRESULT) -> Bool {
+    hr < 0
+}
+
 @inline(__always)
 package func HRESULT_CODE(_ hr: HRESULT) -> DWORD {
     DWORD(hr) & 0xffff

Tests/FoundationEssentialsTests/FileManager/FileManagerTests.swift

@@ -399,8 +399,12 @@ final class FileManagerTests : XCTestCase {
             XCTAssertEqual(try $0.subpathsOfDirectory(atPath: ".").sorted(), ["dir", "dir/bar", "dir/foo", "dir2", "dir2/bar", "dir2/foo", "other_file"])
             XCTAssertEqual($0.contents(atPath: "dir/foo"), data)
             XCTAssertEqual($0.contents(atPath: "dir2/foo"), data)
+#if os(Windows)
+            XCTAssertEqual($0.delegateCaptures.shouldCopy, [.init("dir", "dir2"), .init("dir/bar", "dir2/bar"), .init("dir/foo", "dir2/foo")])
+#else
             XCTAssertEqual($0.delegateCaptures.shouldCopy, [.init("dir", "dir2"), .init("dir/foo", "dir2/foo"), .init("dir/bar", "dir2/bar")])
-            
+#endif
+
             XCTAssertThrowsError(try $0.copyItem(atPath: "does_not_exist", toPath: "dir3")) {
                 XCTAssertEqual(($0 as? CocoaError)?.code, .fileReadNoSuchFile)
             }