chore(cache): minimize tar isolation diff

Restore the existing helper layout and separate test cases rather than
bundling unrelated consolidation with the bug fix. Leave archive creation
unchanged and retain only the read isolation, necessary path handling,
and regression coverage.

__tests__/tar.test.ts

@@ -84,56 +84,57 @@ test('zstd extract tar', async () => {
   )
 })
 
-test.each([
-  {operation: 'extract', read: tar.extractTar, flag: '-xf'},
-  {operation: 'list', read: tar.listTar, flag: '-tf'}
-])(
-  'zstd $operation tar with windows BSDtar',
-  async ({operation, read, flag}) => {
-    if (!IS_WINDOWS) {
-      return
-    }
+test('zstd extract tar with windows BSDtar', async () => {
+  if (IS_WINDOWS) {
     const mkdirMock = jest.spyOn(io, 'mkdirP')
     const execMock = jest.spyOn(exec, 'exec')
     const tempDirectory = getTempDir()
     jest.spyOn(utils, 'createTempDirectory').mockResolvedValue(tempDirectory)
-    jest.spyOn(utils, 'getGnuTarPathOnWindows').mockResolvedValue('')
+    jest
+      .spyOn(utils, 'getGnuTarPathOnWindows')
+      .mockReturnValue(Promise.resolve(''))
 
     const archivePath = `${process.env['windir']}\\fakepath\\cache.tar`
     const workspace = process.env['GITHUB_WORKSPACE']
-    const options = {
-      cwd: tempDirectory,
-      env: expect.objectContaining(defaultEnv)
-    }
-    const tarArgs = [`"${SystemTarPathOnWindows}"`, flag, TarFilename, '-P']
-    if (operation === 'extract') {
-      tarArgs.push('-C', `"${workspace?.replace(/\\/g, '/')}"`)
-    }
+    const tarPath = SystemTarPathOnWindows
 
-    await read(archivePath, CompressionMethod.Zstd)
+    await tar.extractTar(archivePath, CompressionMethod.Zstd)
 
-    if (operation === 'extract') {
-      expect(mkdirMock).toHaveBeenCalledWith(workspace)
-    }
+    expect(mkdirMock).toHaveBeenCalledWith(workspace)
     expect(execMock).toHaveBeenCalledTimes(2)
+
     expect(execMock).toHaveBeenNthCalledWith(
       1,
       [
         'zstd -d --long=30 --force -o',
-        TarFilename,
-        `"${archivePath.replace(/\\/g, '/')}"`
+        TarFilename.replace(new RegExp(`\\${path.sep}`, 'g'), '/'),
+        `"${archivePath.replace(new RegExp(`\\${path.sep}`, 'g'), '/')}"`
       ].join(' '),
       undefined,
-      options
+      {
+        cwd: tempDirectory,
+        env: expect.objectContaining(defaultEnv)
+      }
     )
+
     expect(execMock).toHaveBeenNthCalledWith(
       2,
-      tarArgs.join(' '),
+      [
+        `"${tarPath}"`,
+        '-xf',
+        TarFilename.replace(new RegExp(`\\${path.sep}`, 'g'), '/'),
+        '-P',
+        '-C',
+        `"${workspace?.replace(/\\/g, '/')}"`
+      ].join(' '),
       undefined,
-      options
+      {
+        cwd: tempDirectory,
+        env: expect.objectContaining(defaultEnv)
+      }
     )
   }
-)
+})
 
 test('gzip extract tar', async () => {
   const mkdirMock = jest.spyOn(io, 'mkdirP')
@@ -279,7 +280,7 @@ test('zstd create tar with windows BSDtar', async () => {
         TarFilename.replace(/\\/g, '/'),
         '-P',
         '-C',
-        `"${workspace?.replace(/\\/g, '/')}"`,
+        workspace?.replace(/\\/g, '/'),
         '--files-from',
         ManifestFilename
       ].join(' '),
@@ -379,6 +380,52 @@ test('zstd list tar', async () => {
   )
 })
 
+test('zstd list tar with windows BSDtar', async () => {
+  if (IS_WINDOWS) {
+    const execMock = jest.spyOn(exec, 'exec')
+    const tempDirectory = getTempDir()
+    jest.spyOn(utils, 'createTempDirectory').mockResolvedValue(tempDirectory)
+    jest
+      .spyOn(utils, 'getGnuTarPathOnWindows')
+      .mockReturnValue(Promise.resolve(''))
+    const archivePath = `${process.env['windir']}\\fakepath\\cache.tar`
+
+    await tar.listTar(archivePath, CompressionMethod.Zstd)
+
+    const tarPath = SystemTarPathOnWindows
+    expect(execMock).toHaveBeenCalledTimes(2)
+
+    expect(execMock).toHaveBeenNthCalledWith(
+      1,
+      [
+        'zstd -d --long=30 --force -o',
+        TarFilename.replace(new RegExp(`\\${path.sep}`, 'g'), '/'),
+        `"${archivePath.replace(new RegExp(`\\${path.sep}`, 'g'), '/')}"`
+      ].join(' '),
+      undefined,
+      {
+        cwd: tempDirectory,
+        env: expect.objectContaining(defaultEnv)
+      }
+    )
+
+    expect(execMock).toHaveBeenNthCalledWith(
+      2,
+      [
+        `"${tarPath}"`,
+        '-tf',
+        TarFilename.replace(new RegExp(`\\${path.sep}`, 'g'), '/'),
+        '-P'
+      ].join(' '),
+      undefined,
+      {
+        cwd: tempDirectory,
+        env: expect.objectContaining(defaultEnv)
+      }
+    )
+  }
+})
+
 test('zstdWithoutLong list tar', async () => {
   const execMock = jest.spyOn(exec, 'exec')
 

src/internal/tar.ts

@@ -19,17 +19,6 @@ interface TarCommands {
   requiresTempDirectory: boolean
 }
 
-function isBsdTarZstd(
-  tarPath: ArchiveTool,
-  compressionMethod: CompressionMethod
-): boolean {
-  return (
-    IS_WINDOWS &&
-    tarPath.type === ArchiveToolType.BSD &&
-    compressionMethod !== CompressionMethod.Gzip
-  )
-}
-
 // Returns tar path and type: BSD or GNU
 async function getTarPath(): Promise<ArchiveTool> {
   switch (process.platform) {
@@ -74,16 +63,14 @@ async function getTarArgs(
   archivePath = ''
 ): Promise<string[]> {
   const args = [`"${tarPath.path}"`]
-  const BSD_TAR_ZSTD = isBsdTarZstd(tarPath, compressionMethod)
-  const tarFile = BSD_TAR_ZSTD
-    ? TarFilename
-    : (type === 'create'
-        ? utils.getCacheFileName(compressionMethod)
-        : archivePath
-      ).replace(new RegExp(`\\${path.sep}`, 'g'), '/')
-  const workingDirectory = BSD_TAR_ZSTD
-    ? quoteAbsolutePath(getWorkingDirectory())
-    : getWorkingDirectory().replace(new RegExp(`\\${path.sep}`, 'g'), '/')
+  const cacheFileName = utils.getCacheFileName(compressionMethod)
+  const tarFile = 'cache.tar'
+  const workingDirectory = getWorkingDirectory()
+  // Speficic args for BSD tar on windows for workaround
+  const BSD_TAR_ZSTD =
+    tarPath.type === ArchiveToolType.BSD &&
+    compressionMethod !== CompressionMethod.Gzip &&
+    IS_WINDOWS
 
   // Method specific args
   switch (type) {
@@ -91,21 +78,41 @@ async function getTarArgs(
       args.push(
         '--posix',
         '-cf',
-        tarFile,
+        BSD_TAR_ZSTD
+          ? tarFile
+          : cacheFileName.replace(new RegExp(`\\${path.sep}`, 'g'), '/'),
         '--exclude',
-        tarFile,
+        BSD_TAR_ZSTD
+          ? tarFile
+          : cacheFileName.replace(new RegExp(`\\${path.sep}`, 'g'), '/'),
         '-P',
         '-C',
-        workingDirectory,
+        workingDirectory.replace(new RegExp(`\\${path.sep}`, 'g'), '/'),
         '--files-from',
         ManifestFilename
       )
       break
     case 'extract':
-      args.push('-xf', tarFile, '-P', '-C', workingDirectory)
+      args.push(
+        '-xf',
+        BSD_TAR_ZSTD
+          ? tarFile
+          : archivePath.replace(new RegExp(`\\${path.sep}`, 'g'), '/'),
+        '-P',
+        '-C',
+        BSD_TAR_ZSTD
+          ? quoteAbsolutePath(workingDirectory)
+          : workingDirectory.replace(new RegExp(`\\${path.sep}`, 'g'), '/')
+      )
       break
     case 'list':
-      args.push('-tf', tarFile, '-P')
+      args.push(
+        '-tf',
+        BSD_TAR_ZSTD
+          ? tarFile
+          : archivePath.replace(new RegExp(`\\${path.sep}`, 'g'), '/'),
+        '-P'
+      )
       break
   }
 
@@ -143,7 +150,10 @@ async function getCommands(
     type !== 'create'
       ? await getDecompressionProgram(tarPath, compressionMethod, archivePath)
       : await getCompressionProgram(tarPath, compressionMethod)
-  const BSD_TAR_ZSTD = isBsdTarZstd(tarPath, compressionMethod)
+  const BSD_TAR_ZSTD =
+    tarPath.type === ArchiveToolType.BSD &&
+    compressionMethod !== CompressionMethod.Gzip &&
+    IS_WINDOWS
 
   if (BSD_TAR_ZSTD && type !== 'create') {
     args = [[...compressionArgs].join(' '), [...tarArgs].join(' ')]
@@ -175,7 +185,10 @@ async function getDecompressionProgram(
   // unzstd is equivalent to 'zstd -d'
   // --long=#: Enables long distance matching with # bits. Maximum is 30 (1GB) on 32-bit OS and 31 (2GB) on 64-bit.
   // Using 30 here because we also support 32-bit self-hosted runners.
-  const BSD_TAR_ZSTD = isBsdTarZstd(tarPath, compressionMethod)
+  const BSD_TAR_ZSTD =
+    tarPath.type === ArchiveToolType.BSD &&
+    compressionMethod !== CompressionMethod.Gzip &&
+    IS_WINDOWS
   switch (compressionMethod) {
     case CompressionMethod.Zstd:
       return BSD_TAR_ZSTD
@@ -208,7 +221,10 @@ async function getCompressionProgram(
   compressionMethod: CompressionMethod
 ): Promise<string[]> {
   const cacheFileName = utils.getCacheFileName(compressionMethod)
-  const BSD_TAR_ZSTD = isBsdTarZstd(tarPath, compressionMethod)
+  const BSD_TAR_ZSTD =
+    tarPath.type === ArchiveToolType.BSD &&
+    compressionMethod !== CompressionMethod.Gzip &&
+    IS_WINDOWS
   switch (compressionMethod) {
     case CompressionMethod.Zstd:
       return BSD_TAR_ZSTD