refactor: simplify split-cache handling

Restore cache entries sequentially, keep saves parallel with per-entry error handling, and simplify the cache test setup.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

__tests__/cache-restore.test.ts

@@ -2,7 +2,6 @@
 
 import {jest, describe, it, expect, beforeEach, afterEach} from '@jest/globals';
 import fs from 'fs';
-import path from 'path';
 
 jest.unstable_mockModule('@actions/cache', () => ({
   saveCache: jest.fn(),
@@ -88,10 +87,6 @@ describe('restoreCache', () => {
   ];
   const originalEnv = {...process.env};
   const originalArch = Object.getOwnPropertyDescriptor(process, 'arch')!;
-  const originalPlatform = Object.getOwnPropertyDescriptor(
-    process,
-    'platform'
-  )!;
 
   beforeEach(() => {
     jest.resetAllMocks();
@@ -102,7 +97,6 @@ describe('restoreCache', () => {
       ImageOS: 'ubuntu24'
     };
     Object.defineProperty(process, 'arch', {value: 'x64'});
-    Object.defineProperty(process, 'platform', {value: 'linux'});
     hashFilesSpy.mockResolvedValue('file_hash');
     getCacheDirectoryPathSpy.mockResolvedValue(directories);
     restoreCacheSpy.mockResolvedValue(undefined);
@@ -112,7 +106,6 @@ describe('restoreCache', () => {
   afterEach(() => {
     process.env = {...originalEnv};
     Object.defineProperty(process, 'arch', originalArch);
-    Object.defineProperty(process, 'platform', originalPlatform);
     jest.restoreAllMocks();
   });
 
@@ -153,15 +146,9 @@ describe('restoreCache', () => {
     expect(infoSpy).toHaveBeenCalledWith('build cache is not found');
   });
 
-  it.each([
+  it.each([false, true])(
-    {platform: 'linux', firstFails: false},
+    'restores entries sequentially and waits for both (first fails=%s)',
-    {platform: 'linux', firstFails: true},
+    async firstFails => {
-    {platform: 'win32', firstFails: false},
-    {platform: 'win32', firstFails: true}
-  ])(
-    'starts both restores concurrently on $platform and waits for both (first fails=$firstFails)',
-    async ({platform, firstFails}) => {
-      Object.defineProperty(process, 'platform', {value: platform});
       const started = [deferred(), deferred()];
       const release = [deferred(), deferred()];
       let completed = false;
@@ -179,10 +166,14 @@ describe('restoreCache', () => {
         completed = true;
       });
       try {
-        await Promise.all(started.map(signal => signal.promise));
+        await started[0].promise;
+        expect(restoreCacheSpy).toHaveBeenCalledTimes(1);
+        expect(core.saveState).not.toHaveBeenCalled();
+        expect(setOutputSpy).not.toHaveBeenCalledWith('cache-hit', true);
+
         release[0].resolve();
-        // Let the first completion propagate while the second stays blocked.
+        await started[1].promise;
-        await new Promise<void>(resolve => setImmediate(resolve));
+        expect(restoreCacheSpy).toHaveBeenCalledTimes(2);
         expect(completed).toBe(false);
         expect(core.saveState).not.toHaveBeenCalled();
         expect(setOutputSpy).not.toHaveBeenCalledWith('cache-hit', true);
@@ -196,38 +187,6 @@ describe('restoreCache', () => {
     }
   );
 
-  it.each(['linux', 'win32'])(
-    'restores overlapping directories sequentially on %s',
-    async platform => {
-      Object.defineProperty(process, 'platform', {value: platform});
-      getCacheDirectoryPathSpy.mockResolvedValue([
-        directories[0],
-        {kind: 'build', path: path.join(modulePath, 'build')}
-      ]);
-      const firstStarted = deferred();
-      const releaseFirst = deferred();
-      restoreCacheSpy.mockImplementation(async (paths, key) => {
-        if (paths[0] === modulePath) {
-          firstStarted.resolve();
-          await releaseFirst.promise;
-        }
-        return key;
-      });
-
-      const pending = restore();
-      try {
-        await firstStarted.promise;
-        expect(restoreCacheSpy).toHaveBeenCalledTimes(1);
-      } finally {
-        releaseFirst.resolve();
-        await pending;
-      }
-
-      expect(restoreCacheSpy).toHaveBeenCalledTimes(2);
-      expect(setOutputSpy).toHaveBeenLastCalledWith('cache-hit', true);
-    }
-  );
-
   it.each([
     {modules: false, build: false},
     {modules: true, build: false},

__tests__/cache-save.test.ts

@@ -41,16 +41,17 @@ function deferred() {
 describe('cache-save', () => {
   let entries: CacheEntry[];
 
-  let getBooleanInputSpy: jest.Mock<typeof core.getBooleanInput>;
+  const getBooleanInputSpy = jest.mocked(core.getBooleanInput);
-  let getStateSpy: jest.Mock<typeof core.getState>;
+  const getStateSpy = jest.mocked(core.getState);
-  let infoSpy: jest.Mock<typeof core.info>;
+  const infoSpy = jest.mocked(core.info);
-  let warningSpy: jest.Mock<typeof core.warning>;
+  const warningSpy = jest.mocked(core.warning);
-  let debugSpy: jest.Mock<typeof core.debug>;
+  const debugSpy = jest.mocked(core.debug);
-  let setFailedSpy: jest.Mock<typeof core.setFailed>;
+  const setFailedSpy = jest.mocked(core.setFailed);
-  let saveCacheSpy: jest.Mock<typeof cache.saveCache>;
+  const saveCacheSpy = jest.mocked(cache.saveCache);
-  let existsSpy: jest.Mock<typeof fs.existsSync>;
+  const existsSpy = jest.mocked(fs.existsSync);
 
   beforeEach(() => {
+    jest.resetAllMocks();
     entries = [
       {
         kind: 'modules',
@@ -64,36 +65,14 @@ describe('cache-save', () => {
       }
     ];
 
-    getBooleanInputSpy = core.getBooleanInput as jest.Mock<
-      typeof core.getBooleanInput
-    >;
     getBooleanInputSpy.mockReturnValue(true);
-
-    getStateSpy = core.getState as jest.Mock<typeof core.getState>;
     getStateSpy.mockImplementation(() => JSON.stringify(entries));
-
+    saveCacheSpy.mockResolvedValue(0);
-    infoSpy = core.info as jest.Mock<typeof core.info>;
+    existsSpy.mockReturnValue(true);
-    infoSpy.mockImplementation(() => undefined);
-
-    warningSpy = core.warning as jest.Mock<typeof core.warning>;
-    warningSpy.mockImplementation(() => undefined);
-
-    debugSpy = core.debug as jest.Mock<typeof core.debug>;
-    debugSpy.mockImplementation(() => undefined);
-
-    setFailedSpy = core.setFailed as jest.Mock<typeof core.setFailed>;
-    setFailedSpy.mockImplementation(() => undefined);
-
-    saveCacheSpy = cache.saveCache as jest.Mock<typeof cache.saveCache>;
-    saveCacheSpy.mockImplementation(() => Promise.resolve(0));
-
-    existsSpy = fs.existsSync as jest.Mock<typeof fs.existsSync>;
-    existsSpy.mockImplementation(() => true);
   });
 
   afterEach(() => {
     jest.restoreAllMocks();
-    jest.clearAllMocks();
   });
 
   it('does not save cache when the cache input is false', async () => {
@@ -146,7 +125,7 @@ describe('cache-save', () => {
   );
 
   it('does not save cache when there are no cache folders on the disk', async () => {
-    existsSpy.mockImplementation(() => false);
+    existsSpy.mockReturnValue(false);
 
     await run();
 

__tests__/cache-utils.test.ts

@@ -1,14 +1,4 @@
-import {
+import {jest, describe, it, expect, beforeEach, afterAll} from '@jest/globals';
-  jest,
-  describe,
-  it,
-  expect,
-  beforeEach,
-  afterEach,
-  afterAll
-} from '@jest/globals';
-import fs from 'fs';
-import path from 'path';
 
 jest.unstable_mockModule('@actions/exec', () => ({
   exec: jest.fn(),
@@ -212,139 +202,6 @@ describe('getCacheDirectoryPath', () => {
   });
 });
 
-describe('canRestoreCachesInParallel', () => {
-  const originalPlatform = Object.getOwnPropertyDescriptor(
-    process,
-    'platform'
-  )!;
-  const directoryStat = fs.lstatSync(process.cwd());
-
-  beforeEach(() => {
-    Object.defineProperty(process, 'platform', {value: 'linux'});
-    jest.spyOn(fs, 'lstatSync').mockReturnValue(directoryStat);
-    jest
-      .spyOn(fs, 'realpathSync')
-      .mockImplementation(directory => path.resolve(directory.toString()));
-  });
-
-  afterEach(() => {
-    Object.defineProperty(process, 'platform', originalPlatform);
-    jest.restoreAllMocks();
-  });
-
-  it.each([
-    {modules: 'cache/modules', build: 'cache/build', parallel: true},
-    {modules: 'cache', build: 'cache-build', parallel: true},
-    {modules: 'cache', build: 'cache', parallel: false},
-    {modules: 'cache', build: 'cache/build', parallel: false},
-    {modules: 'cache/modules', build: 'cache', parallel: false},
-    {modules: 'cache', build: 'cache/../cache', parallel: false}
-  ])(
-    'checks overlapping paths: $modules and $build',
-    ({modules, build, parallel}) => {
-      expect(
-        cacheUtils.canRestoreCachesInParallel([
-          {kind: 'modules', path: modules},
-          {kind: 'build', path: build}
-        ])
-      ).toBe(parallel);
-    }
-  );
-
-  it('allows concurrent Windows restores with disjoint paths', () => {
-    Object.defineProperty(process, 'platform', {value: 'win32'});
-
-    expect(
-      cacheUtils.canRestoreCachesInParallel([
-        {kind: 'modules', path: 'cache/modules'},
-        {kind: 'build', path: 'cache/build'}
-      ])
-    ).toBe(true);
-  });
-
-  it.each(['darwin', 'win32'])(
-    'handles case-insensitive paths conservatively on %s',
-    platform => {
-      Object.defineProperty(process, 'platform', {value: platform});
-
-      expect(
-        cacheUtils.canRestoreCachesInParallel([
-          {kind: 'modules', path: 'cache'},
-          {kind: 'build', path: 'CACHE/build'}
-        ])
-      ).toBe(false);
-    }
-  );
-
-  it.each([true, false])(
-    'serializes symlink aliases with missing cache directories (overlap=%s)',
-    overlap => {
-      const alias = path.resolve('alias');
-      const target = path.resolve('target');
-      jest.spyOn(fs, 'lstatSync').mockImplementation(directory => {
-        if (directory !== alias && directory !== target) {
-          throw Object.assign(new Error('Missing path'), {code: 'ENOENT'});
-        }
-        return directoryStat;
-      });
-      jest.spyOn(fs, 'realpathSync').mockReturnValue(target);
-
-      expect(
-        cacheUtils.canRestoreCachesInParallel([
-          {kind: 'modules', path: path.join(alias, 'modules')},
-          {
-            kind: 'build',
-            path: path.join(target, overlap ? 'modules/build' : 'build')
-          }
-        ])
-      ).toBe(false);
-    }
-  );
-
-  it.each(['nested alias', 'alias through module cache'])(
-    'serializes restores when the %s resolves outside the module cache',
-    scenario => {
-      const modules = path.resolve('modules');
-      const target = path.resolve('external-build');
-      const alias = path.join(modules, 'build-link');
-      const build =
-        scenario === 'nested alias'
-          ? path.join(alias, 'cache')
-          : path.resolve('build-alias', 'cache');
-      jest.spyOn(fs, 'realpathSync').mockImplementation(directory => {
-        const absolute = path.resolve(directory.toString());
-        if (absolute === build) {
-          return path.join(target, 'cache');
-        }
-        if (absolute === path.dirname(build)) {
-          return scenario === 'nested alias' ? target : alias;
-        }
-        return absolute;
-      });
-
-      expect(
-        cacheUtils.canRestoreCachesInParallel([
-          {kind: 'modules', path: modules},
-          {kind: 'build', path: build}
-        ])
-      ).toBe(false);
-    }
-  );
-
-  it('falls back to sequential restores when path resolution fails', () => {
-    jest.spyOn(fs, 'realpathSync').mockImplementation(() => {
-      throw new Error('Cannot resolve path');
-    });
-
-    expect(
-      cacheUtils.canRestoreCachesInParallel([
-        {kind: 'modules', path: 'cache/modules'},
-        {kind: 'build', path: 'cache/build'}
-      ])
-    ).toBe(false);
-  });
-});
-
 describe('isCacheFeatureAvailable', () => {
   //Arrange
   const isFeatureAvailableSpy = cache.isFeatureAvailable as jest.Mock<

dist/cache-save/index.js

@@ -96684,17 +96684,10 @@ const cachePackages = async () => {
         info('Cache keys were not generated. Please check the log messages above for more errors or information');
         return;
     }
-    await Promise.all(entries.map(async (entry) => {
+    await Promise.all(entries.map(saveCacheEntry));
-        try {
-            await saveCacheEntry(entry);
-        }
-        catch (error) {
-            const message = error instanceof Error ? error.message : String(error);
-            warning(`Save ${entry.kind} cache failed: ${message}`);
-        }
-    }));
 };
 const saveCacheEntry = async (entry) => {
+    try {
         const { kind, path, primaryKey, matchedKey } = entry;
         if (primaryKey === matchedKey) {
             info(`Cache hit occurred on the primary key ${primaryKey}, not saving cache.`);
@@ -96713,6 +96706,11 @@ const saveCacheEntry = async (entry) => {
             return;
         }
         info(`Cache saved with the key: ${primaryKey}`);
+    }
+    catch (error) {
+        const message = error instanceof Error ? error.message : String(error);
+        warning(`Save ${entry.kind} cache failed: ${message}`);
+    }
 };
 function logWarning(message) {
     const warningPrefix = '[warning]';

dist/setup/index.js

@@ -97991,8 +97991,6 @@ const supportedPackageManagers = {
 
 
 
-
-
 const getCommandOutput = async (toolCommand) => {
     let { stdout, stderr, exitCode } = await getExecOutput(toolCommand, undefined, { ignoreReturnCode: true });
     if (exitCode) {
@@ -98031,58 +98029,6 @@ const getCacheDirectoryPath = async (packageManagerInfo) => {
     }
     return cachePaths;
 };
-function canRestoreCachesInParallel(directories) {
-    try {
-        const paths = directories.map(directory => {
-            const resolvedPath = resolveCachePath(directory.path);
-            // Conservatively handle case-insensitive Windows/macOS filesystems.
-            return process.platform === 'darwin' || process.platform === 'win32'
-                ? resolvedPath.toLowerCase()
-                : resolvedPath;
-        });
-        // A cache archive can replace symlinks traversed by the other restore.
-        // Canonical destinations alone do not capture that extraction footprint.
-        if (paths.some((resolvedPath, index) => {
-            const absolutePath = external_path_default().resolve(directories[index].path);
-            const normalizedPath = process.platform === 'darwin' || process.platform === 'win32'
-                ? absolutePath.toLowerCase()
-                : absolutePath;
-            return resolvedPath !== normalizedPath;
-        })) {
-            return false;
-        }
-        return paths.every((parent, index) => paths.every((child, otherIndex) => {
-            if (index === otherIndex) {
-                return true;
-            }
-            const relative = external_path_default().relative(parent, child);
-            return (relative === '..' ||
-                relative.startsWith(`..${(external_path_default()).sep}`) ||
-                external_path_default().isAbsolute(relative));
-        }));
-    }
-    catch {
-        // If the paths cannot be resolved safely, avoid concurrent extraction.
-        return false;
-    }
-}
-function resolveCachePath(directory) {
-    const absolutePath = external_path_default().resolve(directory);
-    try {
-        external_fs_default().lstatSync(absolutePath);
-    }
-    catch (error) {
-        const parent = external_path_default().dirname(absolutePath);
-        if (error.code !== 'ENOENT' ||
-            parent === absolutePath) {
-            throw error;
-        }
-        // Cold cache directories may not exist yet. Resolve their existing
-        // ancestors so symlink aliases still participate in the overlap check.
-        return external_path_default().join(resolveCachePath(parent), external_path_default().basename(absolutePath));
-    }
-    return external_fs_default().realpathSync(absolutePath);
-}
 function cache_utils_isGhes() {
     const ghUrl = new URL(process.env['GITHUB_SERVER_URL'] || 'https://github.com');
     const hostname = ghUrl.hostname.trimEnd().toUpperCase();
@@ -98135,7 +98081,7 @@ const cache_restore_restoreCache = async (versionSpec, packageManager, cacheDepe
         ...directory,
         primaryKey: primaryKeys[directory.kind]
     }));
-    const restoreEntry = async (entry) => {
+    for (const entry of entries) {
         core_debug(`${entry.kind} primary key is ${entry.primaryKey}`);
         try {
             entry.matchedKey = await restoreCache([entry.path], entry.primaryKey);
@@ -98150,14 +98096,6 @@ const cache_restore_restoreCache = async (versionSpec, packageManager, cacheDepe
             const message = error instanceof Error ? error.message : String(error);
             warning(`Restore ${entry.kind} cache failed: ${message}`);
         }
-    };
-    if (canRestoreCachesInParallel(entries)) {
-        await Promise.all(entries.map(restoreEntry));
-    }
-    else {
-        for (const entry of entries) {
-            await restoreEntry(entry);
-        }
     }
     // Preserve the resolved paths so the post step uses the same cache versions,
     // even if a later step changes the Go environment.

docs/advanced-usage.md

@@ -248,7 +248,7 @@ The action restores and saves two independent cache entries:
 
 Both entries use the content hash of files listed by `cache-dependency-path`, or the root `go.mod` by default. Adding source files or build settings to that input invalidates both entries when those files change. Custom cache locations and the cache service's normal access restrictions still apply.
 
-Each entry is restored and saved independently. An exact hit is not uploaded again. A failure for one entry does not prevent caching the other. The `cache-hit` output is `true` only when both entries are restored on their primary keys.
+Each entry is restored and saved independently. Restores run sequentially to avoid concurrent extraction into overlapping custom cache directories. An exact hit is not uploaded again. A failure for one entry does not prevent caching the other. The `cache-hit` output is `true` only when both entries are restored on their primary keys.
 
 ### Caching in monorepos
 

src/cache-restore.ts

@@ -8,7 +8,6 @@ import {State, Outputs} from './constants.js';
 import {PackageManagerInfo} from './package-managers.js';
 import {
   CacheEntry,
-  canRestoreCachesInParallel,
   getCacheDirectoryPath,
   getPackageManagerInfo
 } from './cache-utils.js';
@@ -49,7 +48,7 @@ export const restoreCache = async (
     primaryKey: primaryKeys[directory.kind]
   }));
 
-  const restoreEntry = async (entry: CacheEntry) => {
+  for (const entry of entries) {
     core.debug(`${entry.kind} primary key is ${entry.primaryKey}`);
     try {
       entry.matchedKey = await cache.restoreCache(
@@ -65,14 +64,6 @@ export const restoreCache = async (
       const message = error instanceof Error ? error.message : String(error);
       core.warning(`Restore ${entry.kind} cache failed: ${message}`);
     }
-  };
-
-  if (canRestoreCachesInParallel(entries)) {
-    await Promise.all(entries.map(restoreEntry));
-  } else {
-    for (const entry of entries) {
-      await restoreEntry(entry);
-    }
   }
 
   // Preserve the resolved paths so the post step uses the same cache versions,

src/cache-save.ts

@@ -49,19 +49,11 @@ const cachePackages = async () => {
     return;
   }
 
-  await Promise.all(
+  await Promise.all(entries.map(saveCacheEntry));
-    entries.map(async entry => {
-      try {
-        await saveCacheEntry(entry);
-      } catch (error) {
-        const message = error instanceof Error ? error.message : String(error);
-        core.warning(`Save ${entry.kind} cache failed: ${message}`);
-      }
-    })
-  );
 };
 
 const saveCacheEntry = async (entry: CacheEntry) => {
+  try {
     const {kind, path, primaryKey, matchedKey} = entry;
     if (primaryKey === matchedKey) {
       core.info(
@@ -84,6 +76,10 @@ const saveCacheEntry = async (entry: CacheEntry) => {
       return;
     }
     core.info(`Cache saved with the key: ${primaryKey}`);
+  } catch (error) {
+    const message = error instanceof Error ? error.message : String(error);
+    core.warning(`Save ${entry.kind} cache failed: ${message}`);
+  }
 };
 
 function logWarning(message: string): void {

src/cache-utils.ts

@@ -1,8 +1,6 @@
 import * as cache from '@actions/cache';
 import * as core from '@actions/core';
 import * as exec from '@actions/exec';
-import fs from 'fs';
-import path from 'path';
 import {
   supportedPackageManagers,
   PackageManagerInfo,
@@ -75,69 +73,6 @@ export const getCacheDirectoryPath = async (
   return cachePaths;
 };
 
-export function canRestoreCachesInParallel(
-  directories: CacheDirectory[]
-): boolean {
-  try {
-    const paths = directories.map(directory => {
-      const resolvedPath = resolveCachePath(directory.path);
-      // Conservatively handle case-insensitive Windows/macOS filesystems.
-      return process.platform === 'darwin' || process.platform === 'win32'
-        ? resolvedPath.toLowerCase()
-        : resolvedPath;
-    });
-    // A cache archive can replace symlinks traversed by the other restore.
-    // Canonical destinations alone do not capture that extraction footprint.
-    if (
-      paths.some((resolvedPath, index) => {
-        const absolutePath = path.resolve(directories[index].path);
-        const normalizedPath =
-          process.platform === 'darwin' || process.platform === 'win32'
-            ? absolutePath.toLowerCase()
-            : absolutePath;
-        return resolvedPath !== normalizedPath;
-      })
-    ) {
-      return false;
-    }
-    return paths.every((parent, index) =>
-      paths.every((child, otherIndex) => {
-        if (index === otherIndex) {
-          return true;
-        }
-        const relative = path.relative(parent, child);
-        return (
-          relative === '..' ||
-          relative.startsWith(`..${path.sep}`) ||
-          path.isAbsolute(relative)
-        );
-      })
-    );
-  } catch {
-    // If the paths cannot be resolved safely, avoid concurrent extraction.
-    return false;
-  }
-}
-
-function resolveCachePath(directory: string): string {
-  const absolutePath = path.resolve(directory);
-  try {
-    fs.lstatSync(absolutePath);
-  } catch (error) {
-    const parent = path.dirname(absolutePath);
-    if (
-      (error as NodeJS.ErrnoException).code !== 'ENOENT' ||
-      parent === absolutePath
-    ) {
-      throw error;
-    }
-    // Cold cache directories may not exist yet. Resolve their existing
-    // ancestors so symlink aliases still participate in the overlap check.
-    return path.join(resolveCachePath(parent), path.basename(absolutePath));
-  }
-  return fs.realpathSync(absolutePath);
-}
-
 export function isGhes(): boolean {
   const ghUrl = new URL(
     process.env['GITHUB_SERVER_URL'] || 'https://github.com'