Address comments

packages/cache/__tests__/tar.test.ts

@@ -1,7 +1,11 @@
 import * as exec from '@actions/exec'
 import * as io from '@actions/io'
 import * as path from 'path'
-import {CacheFilename, CompressionMethod} from '../src/internal/constants'
+import {
+  CacheFilename,
+  CompressionMethod,
+  GnuTarPathOnWindows
+} from '../src/internal/constants'
 import * as tar from '../src/internal/tar'
 import * as utils from '../src/internal/cacheUtils'
 // eslint-disable-next-line @typescript-eslint/no-require-imports
@@ -12,7 +16,6 @@ jest.mock('@actions/io')
 
 const IS_WINDOWS = process.platform === 'win32'
 const IS_MAC = process.platform === 'darwin'
-const windowsGnuTar = `${process.env['PROGRAMFILES']}\\Git\\usr\\bin\\tar.exe`
 
 const defaultTarPath = process.platform === 'darwin' ? 'gtar' : 'tar'
 
@@ -46,7 +49,7 @@ test('zstd extract tar', async () => {
     ? `${process.env['windir']}\\fakepath\\cache.tar`
     : 'cache.tar'
   const workspace = process.env['GITHUB_WORKSPACE']
-  const tarPath = IS_WINDOWS ? windowsGnuTar : defaultTarPath
+  const tarPath = IS_WINDOWS ? GnuTarPathOnWindows : defaultTarPath
 
   await tar.extractTar(archivePath, CompressionMethod.Zstd)
 
@@ -80,7 +83,7 @@ test('gzip extract tar', async () => {
   await tar.extractTar(archivePath, CompressionMethod.Gzip)
 
   expect(mkdirMock).toHaveBeenCalledWith(workspace)
-  const tarPath = IS_WINDOWS ? windowsGnuTar : defaultTarPath
+  const tarPath = IS_WINDOWS ? GnuTarPathOnWindows : defaultTarPath
   expect(execMock).toHaveBeenCalledTimes(1)
   expect(execMock).toHaveBeenCalledWith(
     `"${tarPath}"`,
@@ -100,11 +103,10 @@ test('gzip extract tar', async () => {
 
 test('gzip extract GNU tar on windows with GNUtar in path', async () => {
   if (IS_WINDOWS) {
-    jest.spyOn(fs, 'existsSync').mockReturnValue(false)
+    // GNU tar present in path but not at default location
-
     const isGnuMock = jest
-      .spyOn(utils, 'isGnuTarInstalled')
+      .spyOn(utils, 'getGnuTarPathOnWindows')
-      .mockReturnValue(Promise.resolve(true))
+      .mockReturnValue(Promise.resolve('C:\\Program Files\\gnutar\\tar.exe'))
     const execMock = jest.spyOn(exec, 'exec')
     const archivePath = `${process.env['windir']}\\fakepath\\cache.tar`
     const workspace = process.env['GITHUB_WORKSPACE']
@@ -140,7 +142,7 @@ test('zstd create tar', async () => {
 
   await tar.createTar(archiveFolder, sourceDirectories, CompressionMethod.Zstd)
 
-  const tarPath = IS_WINDOWS ? windowsGnuTar : defaultTarPath
+  const tarPath = IS_WINDOWS ? GnuTarPathOnWindows : defaultTarPath
 
   expect(execMock).toHaveBeenCalledTimes(1)
   expect(execMock).toHaveBeenCalledWith(
@@ -178,7 +180,7 @@ test('gzip create tar', async () => {
 
   await tar.createTar(archiveFolder, sourceDirectories, CompressionMethod.Gzip)
 
-  const tarPath = IS_WINDOWS ? windowsGnuTar : defaultTarPath
+  const tarPath = IS_WINDOWS ? GnuTarPathOnWindows : defaultTarPath
 
   expect(execMock).toHaveBeenCalledTimes(1)
   expect(execMock).toHaveBeenCalledWith(
@@ -213,7 +215,7 @@ test('zstd list tar', async () => {
 
   await tar.listTar(archivePath, CompressionMethod.Zstd)
 
-  const tarPath = IS_WINDOWS ? windowsGnuTar : defaultTarPath
+  const tarPath = IS_WINDOWS ? GnuTarPathOnWindows : defaultTarPath
   expect(execMock).toHaveBeenCalledTimes(1)
   expect(execMock).toHaveBeenCalledWith(
     `"${tarPath}"`,
@@ -239,7 +241,7 @@ test('zstdWithoutLong list tar', async () => {
 
   await tar.listTar(archivePath, CompressionMethod.ZstdWithoutLong)
 
-  const tarPath = IS_WINDOWS ? windowsGnuTar : defaultTarPath
+  const tarPath = IS_WINDOWS ? GnuTarPathOnWindows : defaultTarPath
   expect(execMock).toHaveBeenCalledTimes(1)
   expect(execMock).toHaveBeenCalledWith(
     `"${tarPath}"`,
@@ -264,7 +266,7 @@ test('gzip list tar', async () => {
 
   await tar.listTar(archivePath, CompressionMethod.Gzip)
 
-  const tarPath = IS_WINDOWS ? windowsGnuTar : defaultTarPath
+  const tarPath = IS_WINDOWS ? GnuTarPathOnWindows : defaultTarPath
   expect(execMock).toHaveBeenCalledTimes(1)
   expect(execMock).toHaveBeenCalledWith(
     `"${tarPath}"`,

packages/cache/src/internal/cacheUtils.ts

@@ -7,7 +7,11 @@ import * as path from 'path'
 import * as semver from 'semver'
 import * as util from 'util'
 import {v4 as uuidV4} from 'uuid'
-import {CacheFilename, CompressionMethod} from './constants'
+import {
+  CacheFilename,
+  CompressionMethod,
+  GnuTarPathOnWindows
+} from './constants'
 
 // From https://github.com/actions/toolkit/blob/main/packages/tool-cache/src/tool-cache.ts#L23
 export async function createTempDirectory(): Promise<string> {
@@ -90,7 +94,7 @@ async function getVersion(app: string): Promise<string> {
 
 // Use zstandard if possible to maximize cache performance
 export async function getCompressionMethod(): Promise<CompressionMethod> {
-  if (process.platform === 'win32' && !(await isGnuTarInstalled())) {
+  if (process.platform === 'win32' && !(await getGnuTarPathOnWindows())) {
     // Disable zstd due to bug https://github.com/actions/cache/issues/301
     return CompressionMethod.Gzip
   }
@@ -116,12 +120,12 @@ export function getCacheFileName(compressionMethod: CompressionMethod): string {
     : CacheFilename.Zstd
 }
 
-export async function isGnuTarInstalled(): Promise<boolean> {
+export async function getGnuTarPathOnWindows(): Promise<string> {
-  const gnuTar = `${process.env['PROGRAMFILES']}\\Git\\usr\\bin\\tar.exe`
+  if (fs.existsSync(GnuTarPathOnWindows)) {
+    return GnuTarPathOnWindows
+  }
   const versionOutput = await getVersion('tar')
-  return (
+  return versionOutput.toLowerCase().includes('gnu tar') ? io.which('tar') : ''
-    versionOutput.toLowerCase().includes('gnu tar') || fs.existsSync(gnuTar)
-  )
 }
 
 export function assertDefined<T>(name: string, value?: T): T {

packages/cache/src/internal/constants.ts

@@ -21,3 +21,6 @@ export const DefaultRetryDelay = 5000
 // over the socket during this period, the socket is destroyed and the download
 // is aborted.
 export const SocketTimeout = 5000
+
+// The default path of GNUtar on hosted Windows runners
+export const GnuTarPathOnWindows = 'C:\\Program Files\\Git\\usr\\bin\\tar.exe'

packages/cache/src/internal/tar.ts

@@ -14,19 +14,12 @@ async function getTarPath(
   let tarPath = await io.which('tar', true)
   switch (process.platform) {
     case 'win32': {
-      const gnuTar = `${process.env['PROGRAMFILES']}\\Git\\usr\\bin\\tar.exe`
+      const gnuTar = await utils.getGnuTarPathOnWindows()
       const systemTar = `${process.env['windir']}\\System32\\tar.exe`
-      if (existsSync(gnuTar)) {
+      if (gnuTar) {
         // Use GNUtar as default on windows
         args.push('--force-local')
         tarPath = gnuTar
-      } else if (
-        compressionMethod !== CompressionMethod.Gzip ||
-        (await utils.isGnuTarInstalled())
-      ) {
-        // We only use zstandard compression on windows when gnu tar is installed due to
-        // a bug with compressing large files with bsdtar + zstd
-        args.push('--force-local')
       } else if (existsSync(systemTar)) {
         tarPath = systemTar
       }