Add cache restore dryRun option

packages/cache/__tests__/options.test.ts

@@ -9,6 +9,7 @@ const useAzureSdk = true
 const downloadConcurrency = 8
 const timeoutInMs = 30000
 const segmentTimeoutInMs = 3600000
+const dryRun = false
 const uploadConcurrency = 4
 const uploadChunkSize = 32 * 1024 * 1024
 
@@ -19,7 +20,8 @@ test('getDownloadOptions sets defaults', async () => {
     useAzureSdk,
     downloadConcurrency,
     timeoutInMs,
-    segmentTimeoutInMs
+    segmentTimeoutInMs,
+    dryRun
   })
 })
 
@@ -28,7 +30,8 @@ test('getDownloadOptions overrides all settings', async () => {
     useAzureSdk: false,
     downloadConcurrency: 14,
     timeoutInMs: 20000,
-    segmentTimeoutInMs: 3600000
+    segmentTimeoutInMs: 3600000,
+    dryRun: true
   }
 
   const actualOptions = getDownloadOptions(expectedOptions)
@@ -61,7 +64,8 @@ test('getDownloadOptions overrides download timeout minutes', async () => {
     useAzureSdk: false,
     downloadConcurrency: 14,
     timeoutInMs: 20000,
-    segmentTimeoutInMs: 3600000
+    segmentTimeoutInMs: 3600000,
+    dryRun: true
   }
   process.env.SEGMENT_DOWNLOAD_TIMEOUT_MINS = '10'
   const actualOptions = getDownloadOptions(expectedOptions)
@@ -72,4 +76,5 @@ test('getDownloadOptions overrides download timeout minutes', async () => {
   )
   expect(actualOptions.timeoutInMs).toEqual(expectedOptions.timeoutInMs)
   expect(actualOptions.segmentTimeoutInMs).toEqual(600000)
+  expect(actualOptions.dryRun).toEqual(expectedOptions.dryRun)
 })

packages/cache/__tests__/restoreCache.test.ts

@@ -276,3 +276,39 @@ test('restore with cache found for restore key', async () => {
   expect(extractTarMock).toHaveBeenCalledWith(archivePath, compression)
   expect(getCompressionMock).toHaveBeenCalledTimes(1)
 })
+
+test('restore with dry run', async () => {
+  const paths = ['node_modules']
+  const key = 'node-test'
+  const options = {dryRun: true}
+
+  const cacheEntry: ArtifactCacheEntry = {
+    cacheKey: key,
+    scope: 'refs/heads/main',
+    archiveLocation: 'www.actionscache.test/download'
+  }
+  const getCacheMock = jest.spyOn(cacheHttpClient, 'getCacheEntry')
+  getCacheMock.mockImplementation(async () => {
+    return Promise.resolve(cacheEntry)
+  })
+
+  const createTempDirectoryMock = jest.spyOn(cacheUtils, 'createTempDirectory')
+  const downloadCacheMock = jest.spyOn(cacheHttpClient, 'downloadCache')
+
+  const compression = CompressionMethod.Gzip
+  const getCompressionMock = jest
+    .spyOn(cacheUtils, 'getCompressionMethod')
+    .mockReturnValue(Promise.resolve(compression))
+
+  const cacheKey = await restoreCache(paths, key, undefined, options)
+
+  expect(cacheKey).toBe(key)
+  expect(getCompressionMock).toHaveBeenCalledTimes(1)
+  expect(getCacheMock).toHaveBeenCalledWith([key], paths, {
+    compressionMethod: compression,
+    enableCrossOsArchive: false
+  })
+  // creating a tempDir and downloading the cache are skipped
+  expect(createTempDirectoryMock).toHaveBeenCalledTimes(0)
+  expect(downloadCacheMock).toHaveBeenCalledTimes(0)
+})

packages/cache/src/cache.ts

@@ -100,6 +100,11 @@ export async function restoreCache(
       return undefined
     }
 
+    if (options?.dryRun) {
+      core.info('Dry run - skipping download')
+      return cacheEntry.cacheKey
+    }
+
     archivePath = path.join(
       await utils.createTempDirectory(),
       utils.getCacheFileName(compressionMethod)

packages/cache/src/options.ts

@@ -53,6 +53,15 @@ export interface DownloadOptions {
    * @default 3600000
    */
   segmentTimeoutInMs?: number
+
+  /**
+   * Weather to skip downloading the cache entry.
+   * If dryRun is set to true, the restore function will only check if
+   * a matching cache entry exists and return the cache key if it does.
+   *
+   * @default false
+   */
+  dryRun?: boolean
 }
 
 /**
@@ -92,7 +101,8 @@ export function getDownloadOptions(copy?: DownloadOptions): DownloadOptions {
     useAzureSdk: true,
     downloadConcurrency: 8,
     timeoutInMs: 30000,
-    segmentTimeoutInMs: 3600000
+    segmentTimeoutInMs: 3600000,
+    dryRun: false
   }
 
   if (copy) {
@@ -111,6 +121,10 @@ export function getDownloadOptions(copy?: DownloadOptions): DownloadOptions {
     if (typeof copy.segmentTimeoutInMs === 'number') {
       result.segmentTimeoutInMs = copy.segmentTimeoutInMs
     }
+
+    if (typeof copy.dryRun === 'boolean') {
+      result.dryRun = copy.dryRun
+    }
   }
   const segmentDownloadTimeoutMins =
     process.env['SEGMENT_DOWNLOAD_TIMEOUT_MINS']
@@ -129,6 +143,7 @@ export function getDownloadOptions(copy?: DownloadOptions): DownloadOptions {
     `Cache segment download timeout mins env var: ${process.env['SEGMENT_DOWNLOAD_TIMEOUT_MINS']}`
   )
   core.debug(`Segment download timeout (ms): ${result.segmentTimeoutInMs}`)
+  core.debug(`Dry run: ${result.dryRun}`)
 
   return result
 }