Migrate to ESM and upgrade dependencies (#1330)

* Migrate to ESM and upgrade dependencies * Add ESM migration note to README for V7 * Remove unnecessary devDependencies: ts-node, @types/jest * npm audit fix * Upgrade @types/node to version 26.0.0 * Clarify ESM migration details in README for V7 * Update README and dependencies * Fix lint issue
2026-09-16 09:51:28 +00:00 · 2026-07-15 11:40:44 -05:00
parent 54baeea5b3
commit f8cf4291c8
66 changed files with 114064 additions and 103976 deletions
@@ -1,6 +0,0 @@
-# Ignore list
-/*
-
-# Do not ignore these folders:
-!__tests__/
-!src/
@@ -1,51 +0,0 @@
-// This is a reusable configuration file copied from https://github.com/actions/reusable-workflows/tree/main/reusable-configurations. Please don't make changes to this file as it's the subject of an automatic update.
-module.exports = {
-  extends: [
-    'eslint:recommended',
-    'plugin:@typescript-eslint/recommended',
-    'plugin:eslint-plugin-jest/recommended',
-    'eslint-config-prettier'
-  ],
-  parser: '@typescript-eslint/parser',
-  plugins: ['@typescript-eslint', 'eslint-plugin-node', 'eslint-plugin-jest'],
-  rules: {
-    '@typescript-eslint/no-require-imports': 'error',
-    '@typescript-eslint/no-non-null-assertion': 'off',
-    '@typescript-eslint/no-explicit-any': 'off',
-    '@typescript-eslint/no-empty-function': 'off',
-    '@typescript-eslint/ban-ts-comment': [
-      'error',
-      {
-        'ts-ignore': 'allow-with-description'
-      }
-    ],
-    'no-console': 'error',
-    'yoda': 'error',
-    'prefer-const': [
-      'error',
-      {
-        destructuring: 'all'
-      }
-    ],
-    'no-control-regex': 'off',
-    'no-constant-condition': ['error', {checkLoops: false}],
-    'node/no-extraneous-import': 'error'
-  },
-  overrides: [
-    {
-      files: ['**/*{test,spec}.ts'],
-      rules: {
-        '@typescript-eslint/no-unused-vars': 'off',
-        'jest/no-standalone-expect': 'off',
-        'jest/no-conditional-expect': 'off',
-        'no-console': 'off',
-
-      }
-    }
-  ],
-  env: {
-    node: true,
-    es6: true,
-    'jest/globals': true
-  }
-};
@@ -14,4 +14,6 @@ allowed:

 reviewed:
  npm:
-    - "@actions/http-client"
+    - "@actions/http-client"
+    - "balanced-match"
+    - "brace-expansion"
@@ -1,11 +0,0 @@
-// This is a reusable configuration file copied from https://github.com/actions/reusable-workflows/tree/main/reusable-configurations. Please don't make changes to this file as it's the subject of an automatic update.
-module.exports = {
-  printWidth: 80,
-  tabWidth: 2,
-  useTabs: false,
-  semi: true,
-  singleQuote: true,
-  trailingComma: 'none',
-  bracketSpacing: false,
-  arrowParens: 'avoid'
-};
@@ -0,0 +1,10 @@
+{
+  "printWidth": 80,
+  "tabWidth": 2,
+  "useTabs": false,
+  "semi": true,
+  "singleQuote": true,
+  "trailingComma": "none",
+  "bracketSpacing": false,
+  "arrowParens": "avoid"
+}
@@ -11,6 +11,10 @@ This action provides the following functionality for GitHub Actions users:
 - Optionally caching dependencies for pip, pipenv and poetry
 - Registering problem matchers for error output

+## What's new in V7
+
+- Migrated action internals to ESM for compatibility with latest `@actions/*` packages. No changes to action inputs, outputs, or behavior.
+
 ## Breaking changes in V6

 - Upgraded action from node20 to node24
@@ -1,10 +1,62 @@
+import {jest, describe, it, expect, beforeEach, afterEach} from '@jest/globals';
+import {fileURLToPath} from 'url';
 import * as path from 'path';
-import * as core from '@actions/core';
-import * as cache from '@actions/cache';
-import * as exec from '@actions/exec';
-import * as io from '@actions/io';
-import {getCacheDistributor} from '../src/cache-distributions/cache-factory';
-import {State} from '../src/cache-distributions/cache-distributor';
+
+const __dirname = path.dirname(fileURLToPath(import.meta.url));
+
+// Mock @actions modules before importing anything that depends on them
+jest.unstable_mockModule('@actions/core', () => ({
+  info: jest.fn(),
+  warning: jest.fn(),
+  debug: jest.fn(),
+  error: jest.fn(),
+  notice: jest.fn(),
+  setFailed: jest.fn(),
+  setOutput: jest.fn(),
+  getInput: jest.fn(),
+  getBooleanInput: jest.fn(),
+  getMultilineInput: jest.fn(),
+  addPath: jest.fn(),
+  exportVariable: jest.fn(),
+  saveState: jest.fn(),
+  getState: jest.fn(),
+  setSecret: jest.fn(),
+  isDebug: jest.fn(() => false),
+  startGroup: jest.fn(),
+  endGroup: jest.fn(),
+  group: jest.fn((_name: string, fn: () => Promise<unknown>) => fn()),
+  toPlatformPath: jest.fn((p: string) => p),
+  toWin32Path: jest.fn((p: string) => p),
+  toPosixPath: jest.fn((p: string) => p)
+}));
+
+jest.unstable_mockModule('@actions/cache', () => ({
+  saveCache: jest.fn(),
+  restoreCache: jest.fn(),
+  isFeatureAvailable: jest.fn()
+}));
+
+jest.unstable_mockModule('@actions/exec', () => ({
+  exec: jest.fn(),
+  getExecOutput: jest.fn()
+}));
+
+jest.unstable_mockModule('@actions/io', () => ({
+  which: jest.fn(),
+  mkdirP: jest.fn(),
+  rmRF: jest.fn(),
+  mv: jest.fn(),
+  cp: jest.fn()
+}));
+
+// Dynamic imports after mocking
+const core = await import('@actions/core');
+const cache = await import('@actions/cache');
+const exec = await import('@actions/exec');
+const io = await import('@actions/io');
+const {getCacheDistributor} =
+  await import('../src/cache-distributions/cache-factory.js');
+const {State} = await import('../src/cache-distributions/cache-distributor.js');

 describe('restore-cache', () => {
  const pipFileLockHash =
@@ -24,43 +76,38 @@ virtualenvs.in-project = true
 virtualenvs.path = "{cache-dir}/virtualenvs"  # /Users/patrick/Library/Caches/pypoetry/virtualenvs
  `;

-  // core spy
-  let infoSpy: jest.SpyInstance;
-  let warningSpy: jest.SpyInstance;
-  let debugSpy: jest.SpyInstance;
-  let saveStateSpy: jest.SpyInstance;
-  let getStateSpy: jest.SpyInstance;
-  let setOutputSpy: jest.SpyInstance;
-
-  // cache spy
-  let restoreCacheSpy: jest.SpyInstance;
-
-  // exec spy
-  let getExecOutputSpy: jest.SpyInstance;
-
-  // io spy
-  let whichSpy: jest.SpyInstance;
+  let infoSpy: jest.Mock;
+  let warningSpy: jest.Mock;
+  let debugSpy: jest.Mock;
+  let saveStateSpy: jest.Mock;
+  let getStateSpy: jest.Mock;
+  let setOutputSpy: jest.Mock;
+  let restoreCacheSpy: jest.Mock;
+  let getExecOutputSpy: jest.Mock;
+  let whichSpy: jest.Mock;

  beforeEach(() => {
    process.env['RUNNER_OS'] = process.env['RUNNER_OS'] ?? 'linux';

-    infoSpy = jest.spyOn(core, 'info');
-    infoSpy.mockImplementation(input => undefined);
+    infoSpy = core.info as jest.Mock;
+    infoSpy.mockImplementation(() => undefined);

-    warningSpy = jest.spyOn(core, 'warning');
-    warningSpy.mockImplementation(input => undefined);
+    warningSpy = core.warning as jest.Mock;
+    warningSpy.mockImplementation(() => undefined);

-    debugSpy = jest.spyOn(core, 'debug');
-    debugSpy.mockImplementation(input => undefined);
+    debugSpy = core.debug as jest.Mock;
+    debugSpy.mockImplementation(() => undefined);

-    saveStateSpy = jest.spyOn(core, 'saveState');
-    saveStateSpy.mockImplementation(input => undefined);
+    saveStateSpy = core.saveState as jest.Mock;
+    saveStateSpy.mockImplementation(() => undefined);

-    getStateSpy = jest.spyOn(core, 'getState');
-    getStateSpy.mockImplementation(input => undefined);
+    getStateSpy = core.getState as jest.Mock;
+    getStateSpy.mockImplementation(() => undefined);

-    getExecOutputSpy = jest.spyOn(exec, 'getExecOutput');
-    getExecOutputSpy.mockImplementation((input: string) => {
+    getExecOutputSpy = exec.getExecOutput as jest.Mock;
+    (
+      getExecOutputSpy as jest.Mock<typeof exec.getExecOutput>
+    ).mockImplementation(async (input: string) => {
      if (input.includes('pip')) {
        return {stdout: 'pip', stderr: '', exitCode: 0};
      }
@@ -74,17 +121,19 @@ virtualenvs.path = "{cache-dir}/virtualenvs"  # /Users/patrick/Library/Caches/py
      return {stdout: '', stderr: 'Error occured', exitCode: 2};
    });

-    setOutputSpy = jest.spyOn(core, 'setOutput');
-    setOutputSpy.mockImplementation(input => undefined);
+    setOutputSpy = core.setOutput as jest.Mock;
+    setOutputSpy.mockImplementation(() => undefined);

-    restoreCacheSpy = jest.spyOn(cache, 'restoreCache');
-    restoreCacheSpy.mockImplementation(
-      (cachePaths: string[], primaryKey: string, restoreKey?: string) => {
-        return primaryKey;
+    restoreCacheSpy = cache.restoreCache as jest.Mock;
+    (
+      restoreCacheSpy as jest.Mock<typeof cache.restoreCache>
+    ).mockImplementation(
+      (cachePaths: string[], primaryKey: string, restoreKey?: string[]) => {
+        return Promise.resolve(primaryKey);
      }
    );

-    whichSpy = jest.spyOn(io, 'which');
+    whichSpy = io.which as jest.Mock;
    whichSpy.mockImplementation(() => '/path/to/python');
  });

@@ -163,9 +212,13 @@ virtualenvs.path = "{cache-dir}/virtualenvs"  # /Users/patrick/Library/Caches/py
        fileHash,
        cachePaths
      ) => {
-        restoreCacheSpy.mockImplementation(
-          (cachePaths: string[], primaryKey: string, restoreKey?: string) => {
-            return primaryKey.includes(fileHash) ? primaryKey : '';
+        (
+          restoreCacheSpy as jest.Mock<typeof cache.restoreCache>
+        ).mockImplementation(
+          (cachePaths: string[], primaryKey: string, restoreKey?: string[]) => {
+            return Promise.resolve(
+              primaryKey.includes(fileHash) ? primaryKey : ''
+            );
          }
        );

@@ -184,8 +237,8 @@ virtualenvs.path = "{cache-dir}/virtualenvs"  # /Users/patrick/Library/Caches/py
          );
        }

-        const restoredKeys = restoreCacheSpy.mock.results.map(
-          result => result.value
+        const restoredKeys = await Promise.all(
+          restoreCacheSpy.mock.results.map(result => result.value)
        );

        restoredKeys.forEach(restoredKey => {
@@ -284,9 +337,13 @@ virtualenvs.path = "{cache-dir}/virtualenvs"  # /Users/patrick/Library/Caches/py
    ])(
      'restored dependencies for %s by primaryKey',
      async (packageManager, pythonVersion, dependencyFile, fileHash) => {
-        restoreCacheSpy.mockImplementation(
-          (cachePaths: string[], primaryKey: string, restoreKey?: string) => {
-            return primaryKey !== fileHash && restoreKey ? pipFileLockHash : '';
+        (
+          restoreCacheSpy as jest.Mock<typeof cache.restoreCache>
+        ).mockImplementation(
+          (cachePaths: string[], primaryKey: string, restoreKey?: string[]) => {
+            return Promise.resolve(
+              primaryKey !== fileHash && restoreKey ? pipFileLockHash : ''
+            );
          }
        );
        const cacheDistributor = getCacheDistributor(
@@ -1,8 +1,61 @@
-import * as core from '@actions/core';
-import * as cache from '@actions/cache';
-import * as exec from '@actions/exec';
-import {run} from '../src/cache-save';
-import {State} from '../src/cache-distributions/cache-distributor';
+import {jest, describe, it, expect, beforeEach, afterEach} from '@jest/globals';
+import {fileURLToPath} from 'url';
+import path from 'path';
+
+const __dirname = path.dirname(fileURLToPath(import.meta.url));
+
+// Mock @actions modules before importing anything that depends on them
+jest.unstable_mockModule('@actions/core', () => ({
+  info: jest.fn(),
+  warning: jest.fn(),
+  debug: jest.fn(),
+  error: jest.fn(),
+  notice: jest.fn(),
+  setFailed: jest.fn(),
+  setOutput: jest.fn(),
+  getInput: jest.fn(),
+  getBooleanInput: jest.fn(),
+  getMultilineInput: jest.fn(),
+  addPath: jest.fn(),
+  exportVariable: jest.fn(),
+  saveState: jest.fn(),
+  getState: jest.fn(),
+  setSecret: jest.fn(),
+  isDebug: jest.fn(() => false),
+  startGroup: jest.fn(),
+  endGroup: jest.fn(),
+  group: jest.fn((_name: string, fn: () => Promise<unknown>) => fn()),
+  toPlatformPath: jest.fn((p: string) => p),
+  toWin32Path: jest.fn((p: string) => p),
+  toPosixPath: jest.fn((p: string) => p)
+}));
+
+class MockValidationError extends Error {
+  constructor(message: string) {
+    super(message);
+    this.name = 'ValidationError';
+  }
+}
+
+jest.unstable_mockModule('@actions/cache', () => ({
+  saveCache: jest.fn(),
+  restoreCache: jest.fn(),
+  isFeatureAvailable: jest.fn(),
+  ValidationError: MockValidationError,
+  ReserveCacheError: MockValidationError
+}));
+
+jest.unstable_mockModule('@actions/exec', () => ({
+  exec: jest.fn(),
+  getExecOutput: jest.fn()
+}));
+
+// Dynamic imports after mocking
+const core = await import('@actions/core');
+const cache = await import('@actions/cache');
+const exec = await import('@actions/exec');
+const {run} = await import('../src/cache-save.js');
+const {State} = await import('../src/cache-distributions/cache-distributor.js');

 describe('run', () => {
  const pipFileLockHash =
@@ -14,53 +67,54 @@ describe('run', () => {
  const poetryLockHash =
    '571bf984f8d210e6a97f854e479fdd4a2b5af67b5fdac109ec337a0ea16e7836';

-  // core spy
-  let infoSpy: jest.SpyInstance;
-  let warningSpy: jest.SpyInstance;
-  let debugSpy: jest.SpyInstance;
-  let saveStateSpy: jest.SpyInstance;
-  let getStateSpy: jest.SpyInstance;
-  let getInputSpy: jest.SpyInstance;
-  let setFailedSpy: jest.SpyInstance;
-
-  // cache spy
-  let saveCacheSpy: jest.SpyInstance;
-
-  // exec spy
-  let getExecOutputSpy: jest.SpyInstance;
+  let infoSpy: jest.Mock;
+  let warningSpy: jest.Mock;
+  let debugSpy: jest.Mock;
+  let saveStateSpy: jest.Mock;
+  let getStateSpy: jest.Mock;
+  let getInputSpy: jest.Mock;
+  let setFailedSpy: jest.Mock;
+  let saveCacheSpy: jest.Mock;
+  let getExecOutputSpy: jest.Mock;

  let inputs = {} as any;

  beforeEach(() => {
    process.env['RUNNER_OS'] = process.env['RUNNER_OS'] ?? 'linux';

-    infoSpy = jest.spyOn(core, 'info');
-    infoSpy.mockImplementation(input => undefined);
+    infoSpy = core.info as jest.Mock;
+    infoSpy.mockImplementation(() => undefined);

-    warningSpy = jest.spyOn(core, 'warning');
-    warningSpy.mockImplementation(input => undefined);
+    warningSpy = core.warning as jest.Mock;
+    warningSpy.mockImplementation(() => undefined);

-    debugSpy = jest.spyOn(core, 'debug');
-    debugSpy.mockImplementation(input => undefined);
+    debugSpy = core.debug as jest.Mock;
+    debugSpy.mockImplementation(() => undefined);

-    saveStateSpy = jest.spyOn(core, 'saveState');
-    saveStateSpy.mockImplementation(input => undefined);
+    saveStateSpy = core.saveState as jest.Mock;
+    saveStateSpy.mockImplementation(() => undefined);

-    getStateSpy = jest.spyOn(core, 'getState');
-    getStateSpy.mockImplementation(input => {
-      if (input === State.CACHE_PATHS) {
-        return JSON.stringify([__dirname]);
+    getStateSpy = core.getState as jest.Mock;
+    (getStateSpy as jest.Mock<typeof core.getState>).mockImplementation(
+      (input: string) => {
+        if (input === State.CACHE_PATHS) {
+          return JSON.stringify([__dirname]);
+        }
+        return requirementsHash;
      }
-      return requirementsHash;
-    });
+    );

-    setFailedSpy = jest.spyOn(core, 'setFailed');
+    setFailedSpy = core.setFailed as jest.Mock;

-    getInputSpy = jest.spyOn(core, 'getInput');
-    getInputSpy.mockImplementation(input => inputs[input]);
+    getInputSpy = core.getInput as jest.Mock;
+    (getInputSpy as jest.Mock<typeof core.getInput>).mockImplementation(
+      (input: string) => inputs[input]
+    );

-    getExecOutputSpy = jest.spyOn(exec, 'getExecOutput');
-    getExecOutputSpy.mockImplementation((input: string) => {
+    getExecOutputSpy = exec.getExecOutput as jest.Mock;
+    (
+      getExecOutputSpy as jest.Mock<typeof exec.getExecOutput>
+    ).mockImplementation(async (input: string) => {
      if (input.includes('pip')) {
        return {stdout: 'pip', stderr: '', exitCode: 0};
      }
@@ -68,7 +122,7 @@ describe('run', () => {
      return {stdout: '', stderr: 'Error occured', exitCode: 2};
    });

-    saveCacheSpy = jest.spyOn(cache, 'saveCache');
+    saveCacheSpy = cache.saveCache as jest.Mock;
    saveCacheSpy.mockImplementation(() => undefined);
  });

@@ -124,15 +178,17 @@ describe('run', () => {
    it('saves cache from pip', async () => {
      inputs['cache'] = 'pip';
      inputs['python-version'] = '3.10.0';
-      getStateSpy.mockImplementation((name: string) => {
-        if (name === State.CACHE_MATCHED_KEY) {
-          return requirementsHash;
-        } else if (name === State.CACHE_PATHS) {
-          return JSON.stringify([__dirname]);
-        } else {
-          return pipFileLockHash;
+      (getStateSpy as jest.Mock<typeof core.getState>).mockImplementation(
+        (name: string) => {
+          if (name === State.CACHE_MATCHED_KEY) {
+            return requirementsHash;
+          } else if (name === State.CACHE_PATHS) {
+            return JSON.stringify([__dirname]);
+          } else {
+            return pipFileLockHash;
+          }
        }
-      });
+      );

      await run();

@@ -151,15 +207,17 @@ describe('run', () => {
    it('saves cache from pipenv', async () => {
      inputs['cache'] = 'pipenv';
      inputs['python-version'] = '3.10.0';
-      getStateSpy.mockImplementation((name: string) => {
-        if (name === State.CACHE_MATCHED_KEY) {
-          return pipFileLockHash;
-        } else if (name === State.CACHE_PATHS) {
-          return JSON.stringify([__dirname]);
-        } else {
-          return requirementsHash;
+      (getStateSpy as jest.Mock<typeof core.getState>).mockImplementation(
+        (name: string) => {
+          if (name === State.CACHE_MATCHED_KEY) {
+            return pipFileLockHash;
+          } else if (name === State.CACHE_PATHS) {
+            return JSON.stringify([__dirname]);
+          } else {
+            return requirementsHash;
+          }
        }
-      });
+      );

      await run();

@@ -178,15 +236,17 @@ describe('run', () => {
    it('saves cache from poetry', async () => {
      inputs['cache'] = 'poetry';
      inputs['python-version'] = '3.10.0';
-      getStateSpy.mockImplementation((name: string) => {
-        if (name === State.CACHE_MATCHED_KEY) {
-          return poetryLockHash;
-        } else if (name === State.CACHE_PATHS) {
-          return JSON.stringify([__dirname]);
-        } else {
-          return requirementsHash;
+      (getStateSpy as jest.Mock<typeof core.getState>).mockImplementation(
+        (name: string) => {
+          if (name === State.CACHE_MATCHED_KEY) {
+            return poetryLockHash;
+          } else if (name === State.CACHE_PATHS) {
+            return JSON.stringify([__dirname]);
+          } else {
+            return requirementsHash;
+          }
        }
-      });
+      );

      await run();

@@ -205,15 +265,17 @@ describe('run', () => {
    it('saves with -1 cacheId , should not fail workflow', async () => {
      inputs['cache'] = 'poetry';
      inputs['python-version'] = '3.10.0';
-      getStateSpy.mockImplementation((name: string) => {
-        if (name === State.STATE_CACHE_PRIMARY_KEY) {
-          return poetryLockHash;
-        } else if (name === State.CACHE_PATHS) {
-          return JSON.stringify([__dirname]);
-        } else {
-          return requirementsHash;
+      (getStateSpy as jest.Mock<typeof core.getState>).mockImplementation(
+        (name: string) => {
+          if (name === State.STATE_CACHE_PRIMARY_KEY) {
+            return poetryLockHash;
+          } else if (name === State.CACHE_PATHS) {
+            return JSON.stringify([__dirname]);
+          } else {
+            return requirementsHash;
+          }
        }
-      });
+      );

      saveCacheSpy.mockImplementation(() => {
        return -1;
@@ -234,15 +296,17 @@ describe('run', () => {
    it('saves with error from toolkit, should not fail the workflow', async () => {
      inputs['cache'] = 'npm';
      inputs['python-version'] = '3.10.0';
-      getStateSpy.mockImplementation((name: string) => {
-        if (name === State.STATE_CACHE_PRIMARY_KEY) {
-          return poetryLockHash;
-        } else if (name === State.CACHE_PATHS) {
-          return JSON.stringify([__dirname]);
-        } else {
-          return requirementsHash;
+      (getStateSpy as jest.Mock<typeof core.getState>).mockImplementation(
+        (name: string) => {
+          if (name === State.STATE_CACHE_PRIMARY_KEY) {
+            return poetryLockHash;
+          } else if (name === State.CACHE_PATHS) {
+            return JSON.stringify([__dirname]);
+          } else {
+            return requirementsHash;
+          }
        }
-      });
+      );

      saveCacheSpy.mockImplementation(() => {
        throw new cache.ValidationError('Validation failed');
@@ -1,18 +1,70 @@
+import {jest, describe, it, expect, beforeEach, afterEach} from '@jest/globals';
+import {fileURLToPath} from 'url';
 import fs from 'fs';
-
-import {HttpClient} from '@actions/http-client';
-import * as ifm from '@actions/http-client/lib/interfaces';
-import * as tc from '@actions/tool-cache';
-import * as exec from '@actions/exec';
-import * as core from '@actions/core';
-
 import * as path from 'path';
+
+const __dirname = path.dirname(fileURLToPath(import.meta.url));
 import * as semver from 'semver';

-import * as finder from '../src/find-graalpy';
-import {IGraalPyManifestRelease} from '../src/utils';
+// Mock @actions modules
+jest.unstable_mockModule('@actions/core', () => ({
+  info: jest.fn(),
+  warning: jest.fn(),
+  debug: jest.fn(),
+  error: jest.fn(),
+  notice: jest.fn(),
+  setFailed: jest.fn(),
+  setOutput: jest.fn(),
+  getInput: jest.fn(),
+  getBooleanInput: jest.fn(),
+  getMultilineInput: jest.fn(),
+  addPath: jest.fn(),
+  exportVariable: jest.fn(),
+  saveState: jest.fn(),
+  getState: jest.fn(),
+  setSecret: jest.fn(),
+  isDebug: jest.fn(() => false),
+  startGroup: jest.fn(),
+  endGroup: jest.fn(),
+  group: jest.fn((_name: string, fn: () => Promise<unknown>) => fn()),
+  toPlatformPath: jest.fn((p: string) => p),
+  toWin32Path: jest.fn((p: string) => p),
+  toPosixPath: jest.fn((p: string) => p)
+}));

-import manifestData from './data/graalpy.json';
+jest.unstable_mockModule('@actions/tool-cache', () => ({
+  find: jest.fn(),
+  findAllVersions: jest.fn(),
+  downloadTool: jest.fn(),
+  extractZip: jest.fn(),
+  extractTar: jest.fn(),
+  extract7z: jest.fn(),
+  extractXar: jest.fn(),
+  cacheDir: jest.fn(),
+  cacheFile: jest.fn(),
+  getManifestFromRepo: jest.fn(),
+  findFromManifest: jest.fn(),
+  evaluateVersions: jest.fn()
+}));
+
+jest.unstable_mockModule('@actions/exec', () => ({
+  exec: jest.fn(),
+  getExecOutput: jest.fn()
+}));
+
+// Dynamic imports after mocking
+const core = await import('@actions/core');
+const tc = await import('@actions/tool-cache');
+const exec = await import('@actions/exec');
+const finder = await import('../src/find-graalpy.js');
+const utils = await import('../src/utils.js');
+
+// Non-mocked imports
+import {HttpClient} from '@actions/http-client';
+import type * as ifm from '@actions/http-client/lib/interfaces';
+
+import type {IGraalPyManifestRelease} from '../src/utils.js';
+import manifestData from './data/graalpy.json' with {type: 'json'};

 const architecture = 'x64';

@@ -41,39 +93,41 @@ describe('parseGraalPyVersion', () => {
 describe('findGraalPyToolCache', () => {
  const actualGraalPyVersion = '23.0.0';
  const graalpyPath = path.join('GraalPy', actualGraalPyVersion, architecture);
-  let tcFind: jest.SpyInstance;
-  let infoSpy: jest.SpyInstance;
-  let warningSpy: jest.SpyInstance;
-  let debugSpy: jest.SpyInstance;
-  let addPathSpy: jest.SpyInstance;
-  let exportVariableSpy: jest.SpyInstance;
-  let setOutputSpy: jest.SpyInstance;
+  let tcFind: jest.Mock;
+  let infoSpy: jest.Mock;
+  let warningSpy: jest.Mock;
+  let debugSpy: jest.Mock;
+  let addPathSpy: jest.Mock;
+  let exportVariableSpy: jest.Mock;
+  let setOutputSpy: jest.Mock;

  beforeEach(() => {
-    tcFind = jest.spyOn(tc, 'find');
-    tcFind.mockImplementation((toolname: string, pythonVersion: string) => {
-      const semverVersion = new semver.Range(pythonVersion);
-      return semver.satisfies(actualGraalPyVersion, semverVersion)
-        ? graalpyPath
-        : '';
-    });
+    tcFind = tc.find as jest.Mock;
+    (tcFind as jest.Mock<typeof tc.find>).mockImplementation(
+      (toolname: string, pythonVersion: string) => {
+        const semverVersion = new semver.Range(pythonVersion);
+        return semver.satisfies(actualGraalPyVersion, semverVersion)
+          ? graalpyPath
+          : '';
+      }
+    );

-    infoSpy = jest.spyOn(core, 'info');
+    infoSpy = core.info as jest.Mock;
    infoSpy.mockImplementation(() => null);

-    warningSpy = jest.spyOn(core, 'warning');
+    warningSpy = core.warning as jest.Mock;
    warningSpy.mockImplementation(() => null);

-    debugSpy = jest.spyOn(core, 'debug');
+    debugSpy = core.debug as jest.Mock;
    debugSpy.mockImplementation(() => null);

-    addPathSpy = jest.spyOn(core, 'addPath');
+    addPathSpy = core.addPath as jest.Mock;
    addPathSpy.mockImplementation(() => null);

-    exportVariableSpy = jest.spyOn(core, 'exportVariable');
+    exportVariableSpy = core.exportVariable as jest.Mock;
    exportVariableSpy.mockImplementation(() => null);

-    setOutputSpy = jest.spyOn(core, 'setOutput');
+    setOutputSpy = core.setOutput as jest.Mock;
    setOutputSpy.mockImplementation(() => null);
  });

@@ -106,73 +160,74 @@ describe('findGraalPyToolCache', () => {
 });

 describe('findGraalPyVersion', () => {
-  let getBooleanInputSpy: jest.SpyInstance;
-  let warningSpy: jest.SpyInstance;
-  let debugSpy: jest.SpyInstance;
-  let infoSpy: jest.SpyInstance;
-  let addPathSpy: jest.SpyInstance;
-  let exportVariableSpy: jest.SpyInstance;
-  let setOutputSpy: jest.SpyInstance;
-  let tcFind: jest.SpyInstance;
-  let spyExtractZip: jest.SpyInstance;
-  let spyExtractTar: jest.SpyInstance;
-  let spyHttpClient: jest.SpyInstance;
-  let spyExistsSync: jest.SpyInstance;
-  let spyExec: jest.SpyInstance;
-  let spySymlinkSync: jest.SpyInstance;
-  let spyDownloadTool: jest.SpyInstance;
-  let spyFsReadDir: jest.SpyInstance;
-  let spyCacheDir: jest.SpyInstance;
-  let spyChmodSync: jest.SpyInstance;
-  let spyCoreAddPath: jest.SpyInstance;
-  let spyCoreExportVariable: jest.SpyInstance;
+  let getBooleanInputSpy: jest.Mock;
+  let warningSpy: jest.Mock;
+  let debugSpy: jest.Mock;
+  let infoSpy: jest.Mock;
+  let addPathSpy: jest.Mock;
+  let exportVariableSpy: jest.Mock;
+  let setOutputSpy: jest.Mock;
+  let tcFind: jest.Mock;
+  let spyExtractZip: jest.Mock;
+  let spyExtractTar: jest.Mock;
+  let spyHttpClient: jest.SpiedFunction<typeof HttpClient.prototype.getJson>;
+  let spyExistsSync: jest.SpiedFunction<typeof fs.existsSync>;
+  let spyExec: jest.Mock;
+  let spySymlinkSync: jest.SpiedFunction<typeof fs.symlinkSync>;
+  let spyDownloadTool: jest.Mock;
+  let spyFsReadDir: jest.SpiedFunction<typeof fs.readdirSync>;
+  let spyCacheDir: jest.Mock;
+  let spyChmodSync: jest.SpiedFunction<typeof fs.chmodSync>;
+  let spyCoreAddPath: jest.Mock;
+  let spyCoreExportVariable: jest.Mock;
  const env = process.env;

  beforeEach(() => {
-    getBooleanInputSpy = jest.spyOn(core, 'getBooleanInput');
+    getBooleanInputSpy = core.getBooleanInput as jest.Mock;
    getBooleanInputSpy.mockImplementation(() => false);

-    infoSpy = jest.spyOn(core, 'info');
+    infoSpy = core.info as jest.Mock;
    infoSpy.mockImplementation(() => {});

-    warningSpy = jest.spyOn(core, 'warning');
+    warningSpy = core.warning as jest.Mock;
    warningSpy.mockImplementation(() => null);

-    debugSpy = jest.spyOn(core, 'debug');
+    debugSpy = core.debug as jest.Mock;
    debugSpy.mockImplementation(() => null);

-    addPathSpy = jest.spyOn(core, 'addPath');
+    addPathSpy = core.addPath as jest.Mock;
    addPathSpy.mockImplementation(() => null);

-    exportVariableSpy = jest.spyOn(core, 'exportVariable');
+    exportVariableSpy = core.exportVariable as jest.Mock;
    exportVariableSpy.mockImplementation(() => null);

-    setOutputSpy = jest.spyOn(core, 'setOutput');
+    setOutputSpy = core.setOutput as jest.Mock;
    setOutputSpy.mockImplementation(() => null);

-    jest.resetModules();
    process.env = {...env};
-    tcFind = jest.spyOn(tc, 'find');
-    tcFind.mockImplementation((tool: string, version: string) => {
-      const semverRange = new semver.Range(version);
-      let graalpyPath = '';
-      if (semver.satisfies('23.0.0', semverRange)) {
-        graalpyPath = path.join(toolDir, 'GraalPy', '23.0.0', architecture);
+    tcFind = tc.find as jest.Mock;
+    (tcFind as jest.Mock<typeof tc.find>).mockImplementation(
+      (tool: string, version: string) => {
+        const semverRange = new semver.Range(version);
+        let graalpyPath = '';
+        if (semver.satisfies('23.0.0', semverRange)) {
+          graalpyPath = path.join(toolDir, 'GraalPy', '23.0.0', architecture);
+        }
+        return graalpyPath;
      }
-      return graalpyPath;
-    });
+    );

-    spyDownloadTool = jest.spyOn(tc, 'downloadTool');
+    spyDownloadTool = tc.downloadTool as jest.Mock;
    spyDownloadTool.mockImplementation(() => path.join(tempDir, 'GraalPy'));

-    spyExtractZip = jest.spyOn(tc, 'extractZip');
+    spyExtractZip = tc.extractZip as jest.Mock;
    spyExtractZip.mockImplementation(() => tempDir);

-    spyExtractTar = jest.spyOn(tc, 'extractTar');
+    spyExtractTar = tc.extractTar as jest.Mock;
    spyExtractTar.mockImplementation(() => tempDir);

    spyFsReadDir = jest.spyOn(fs, 'readdirSync');
-    spyFsReadDir.mockImplementation((directory: string) => ['GraalPyTest']);
+    spyFsReadDir.mockImplementation(() => ['GraalPyTest'] as any);

    spyHttpClient = jest.spyOn(HttpClient.prototype, 'getJson');
    spyHttpClient.mockImplementation(
@@ -186,7 +241,7 @@ describe('findGraalPyVersion', () => {
      }
    );

-    spyExec = jest.spyOn(exec, 'exec');
+    spyExec = exec.exec as jest.Mock;
    spyExec.mockImplementation(() => undefined);

    spySymlinkSync = jest.spyOn(fs, 'symlinkSync');
@@ -195,9 +250,9 @@ describe('findGraalPyVersion', () => {
    spyExistsSync = jest.spyOn(fs, 'existsSync');
    spyExistsSync.mockReturnValue(true);

-    spyCoreAddPath = jest.spyOn(core, 'addPath');
+    spyCoreAddPath = core.addPath as jest.Mock;

-    spyCoreExportVariable = jest.spyOn(core, 'exportVariable');
+    spyCoreExportVariable = core.exportVariable as jest.Mock;
  });

  afterEach(() => {
@@ -235,7 +290,7 @@ describe('findGraalPyVersion', () => {
  });

  it('found and install successfully', async () => {
-    spyCacheDir = jest.spyOn(tc, 'cacheDir');
+    spyCacheDir = tc.cacheDir as jest.Mock;
    spyCacheDir.mockImplementation(() =>
      path.join(toolDir, 'GraalPy', '23.0.0', architecture)
    );
@@ -262,7 +317,7 @@ describe('findGraalPyVersion', () => {
  });

  it('found and install successfully without environment update', async () => {
-    spyCacheDir = jest.spyOn(tc, 'cacheDir');
+    spyCacheDir = tc.cacheDir as jest.Mock;
    spyCacheDir.mockImplementation(() =>
      path.join(toolDir, 'GraalPy', '23.0.0', architecture)
    );
@@ -310,7 +365,7 @@ describe('findGraalPyVersion', () => {
  });

  it('check-latest enabled version found and install successfully', async () => {
-    spyCacheDir = jest.spyOn(tc, 'cacheDir');
+    spyCacheDir = tc.cacheDir as jest.Mock;
    spyCacheDir.mockImplementation(() =>
      path.join(toolDir, 'GraalPy', '23.0.0', architecture)
    );
@@ -329,14 +384,16 @@ describe('findGraalPyVersion', () => {
  });

  it('check-latest enabled version is not found and used from toolcache', async () => {
-    tcFind.mockImplementationOnce((tool: string, version: string) => {
-      const semverRange = new semver.Range(version);
-      let graalpyPath = '';
-      if (semver.satisfies('22.3.4', semverRange)) {
-        graalpyPath = path.join(toolDir, 'GraalPy', '22.3.4', architecture);
+    (tcFind as jest.Mock<typeof tc.find>).mockImplementationOnce(
+      (tool: string, version: string) => {
+        const semverRange = new semver.Range(version);
+        let graalpyPath = '';
+        if (semver.satisfies('22.3.4', semverRange)) {
+          graalpyPath = path.join(toolDir, 'GraalPy', '22.3.4', architecture);
+        }
+        return graalpyPath;
      }
-      return graalpyPath;
-    });
+    );
    await expect(
      finder.findGraalPyVersion(
        'graalpy-22.3.4',
@@ -353,7 +410,7 @@ describe('findGraalPyVersion', () => {
  });

  it('found and install successfully, pre-release fallback', async () => {
-    spyCacheDir = jest.spyOn(tc, 'cacheDir');
+    spyCacheDir = tc.cacheDir as jest.Mock;
    spyCacheDir.mockImplementation(() =>
      path.join(toolDir, 'GraalPy', '24.1', architecture)
    );
@@ -1,23 +1,83 @@
+import {jest, describe, it, expect, beforeEach, afterEach} from '@jest/globals';
+import {fileURLToPath} from 'url';
 import fs from 'fs';
-
-import * as utils from '../src/utils';
-import {HttpClient} from '@actions/http-client';
-import * as ifm from '@actions/http-client/lib/interfaces';
-import * as tc from '@actions/tool-cache';
-import * as exec from '@actions/exec';
-import * as core from '@actions/core';
-
 import * as path from 'path';
+
+const __dirname = path.dirname(fileURLToPath(import.meta.url));
 import * as semver from 'semver';

-import * as finder from '../src/find-pypy';
-import {
-  IPyPyManifestRelease,
-  IS_WINDOWS,
-  getPyPyVersionFromPath
-} from '../src/utils';
+// Mock @actions modules
+jest.unstable_mockModule('@actions/core', () => ({
+  info: jest.fn(),
+  warning: jest.fn(),
+  debug: jest.fn(),
+  error: jest.fn(),
+  notice: jest.fn(),
+  setFailed: jest.fn(),
+  setOutput: jest.fn(),
+  getInput: jest.fn(),
+  getBooleanInput: jest.fn(),
+  getMultilineInput: jest.fn(),
+  addPath: jest.fn(),
+  exportVariable: jest.fn(),
+  saveState: jest.fn(),
+  getState: jest.fn(),
+  setSecret: jest.fn(),
+  isDebug: jest.fn(() => false),
+  startGroup: jest.fn(),
+  endGroup: jest.fn(),
+  group: jest.fn((_name: string, fn: () => Promise<unknown>) => fn()),
+  toPlatformPath: jest.fn((p: string) => p),
+  toWin32Path: jest.fn((p: string) => p),
+  toPosixPath: jest.fn((p: string) => p)
+}));

-import manifestData from './data/pypy.json';
+jest.unstable_mockModule('@actions/tool-cache', () => ({
+  find: jest.fn(),
+  findAllVersions: jest.fn(),
+  downloadTool: jest.fn(),
+  extractZip: jest.fn(),
+  extractTar: jest.fn(),
+  extract7z: jest.fn(),
+  extractXar: jest.fn(),
+  cacheDir: jest.fn(),
+  cacheFile: jest.fn(),
+  getManifestFromRepo: jest.fn(),
+  findFromManifest: jest.fn(),
+  evaluateVersions: jest.fn()
+}));
+
+jest.unstable_mockModule('@actions/exec', () => ({
+  exec: jest.fn(),
+  getExecOutput: jest.fn()
+}));
+
+// Import real utils BEFORE mock registration to get real function references
+const realUtils = await import('../src/utils.js');
+
+// Mock local utils module for readExactPyPyVersionFile/writeExactPyPyVersionFile
+jest.unstable_mockModule('../src/utils.js', () => ({
+  ...realUtils,
+  readExactPyPyVersionFile: jest.fn(),
+  writeExactPyPyVersionFile: jest.fn()
+}));
+
+// Dynamic imports after mocking
+const core = await import('@actions/core');
+const tc = await import('@actions/tool-cache');
+const exec = await import('@actions/exec');
+const utils = await import('../src/utils.js');
+const finder = await import('../src/find-pypy.js');
+
+// Non-mocked imports
+import {HttpClient} from '@actions/http-client';
+import type * as ifm from '@actions/http-client/lib/interfaces';
+
+import type {IPyPyManifestRelease} from '../src/utils.js';
+import manifestData from './data/pypy.json' with {type: 'json'};
+
+const IS_WINDOWS = utils.IS_WINDOWS;
+const getPyPyVersionFromPath = utils.getPyPyVersionFromPath;

 let architecture: string;

@@ -79,43 +139,45 @@ describe('findPyPyToolCache', () => {
  const actualPythonVersion = '3.6.17';
  const actualPyPyVersion = '7.5.4';
  const pypyPath = path.join('PyPy', actualPythonVersion, architecture);
-  let tcFind: jest.SpyInstance;
-  let spyReadExactPyPyVersion: jest.SpyInstance;
-  let infoSpy: jest.SpyInstance;
-  let warningSpy: jest.SpyInstance;
-  let debugSpy: jest.SpyInstance;
-  let addPathSpy: jest.SpyInstance;
-  let exportVariableSpy: jest.SpyInstance;
-  let setOutputSpy: jest.SpyInstance;
+  let tcFind: jest.Mock;
+  let spyReadExactPyPyVersion: jest.Mock;
+  let infoSpy: jest.Mock;
+  let warningSpy: jest.Mock;
+  let debugSpy: jest.Mock;
+  let addPathSpy: jest.Mock;
+  let exportVariableSpy: jest.Mock;
+  let setOutputSpy: jest.Mock;

  beforeEach(() => {
-    tcFind = jest.spyOn(tc, 'find');
-    tcFind.mockImplementation((toolname: string, pythonVersion: string) => {
-      const semverVersion = new semver.Range(pythonVersion);
-      return semver.satisfies(actualPythonVersion, semverVersion)
-        ? pypyPath
-        : '';
-    });
+    tcFind = tc.find as jest.Mock;
+    (tcFind as jest.Mock<typeof tc.find>).mockImplementation(
+      (toolname: string, pythonVersion: string) => {
+        const semverVersion = new semver.Range(pythonVersion);
+        return semver.satisfies(actualPythonVersion, semverVersion)
+          ? pypyPath
+          : '';
+      }
+    );

-    spyReadExactPyPyVersion = jest.spyOn(utils, 'readExactPyPyVersionFile');
+    spyReadExactPyPyVersion = utils.readExactPyPyVersionFile as jest.Mock;
    spyReadExactPyPyVersion.mockImplementation(() => actualPyPyVersion);

-    infoSpy = jest.spyOn(core, 'info');
+    infoSpy = core.info as jest.Mock;
    infoSpy.mockImplementation(() => null);

-    warningSpy = jest.spyOn(core, 'warning');
+    warningSpy = core.warning as jest.Mock;
    warningSpy.mockImplementation(() => null);

-    debugSpy = jest.spyOn(core, 'debug');
+    debugSpy = core.debug as jest.Mock;
    debugSpy.mockImplementation(() => null);

-    addPathSpy = jest.spyOn(core, 'addPath');
+    addPathSpy = core.addPath as jest.Mock;
    addPathSpy.mockImplementation(() => null);

-    exportVariableSpy = jest.spyOn(core, 'exportVariable');
+    exportVariableSpy = core.exportVariable as jest.Mock;
    exportVariableSpy.mockImplementation(() => null);

-    setOutputSpy = jest.spyOn(core, 'setOutput');
+    setOutputSpy = core.setOutput as jest.Mock;
    setOutputSpy.mockImplementation(() => null);
  });

@@ -159,84 +221,82 @@ describe('findPyPyToolCache', () => {
 });

 describe('findPyPyVersion', () => {
-  let getBooleanInputSpy: jest.SpyInstance;
-  let warningSpy: jest.SpyInstance;
-  let debugSpy: jest.SpyInstance;
-  let infoSpy: jest.SpyInstance;
-  let addPathSpy: jest.SpyInstance;
-  let exportVariableSpy: jest.SpyInstance;
-  let setOutputSpy: jest.SpyInstance;
-  let tcFind: jest.SpyInstance;
-  let spyExtractZip: jest.SpyInstance;
-  let spyExtractTar: jest.SpyInstance;
-  let spyHttpClient: jest.SpyInstance;
-  let spyExistsSync: jest.SpyInstance;
-  let spyExec: jest.SpyInstance;
-  let spySymlinkSync: jest.SpyInstance;
-  let spyDownloadTool: jest.SpyInstance;
-  let spyReadExactPyPyVersion: jest.SpyInstance;
-  let spyFsReadDir: jest.SpyInstance;
-  let spyWriteExactPyPyVersionFile: jest.SpyInstance;
-  let spyCacheDir: jest.SpyInstance;
-  let spyChmodSync: jest.SpyInstance;
-  let spyCoreAddPath: jest.SpyInstance;
-  let spyCoreExportVariable: jest.SpyInstance;
+  let getBooleanInputSpy: jest.Mock;
+  let warningSpy: jest.Mock;
+  let debugSpy: jest.Mock;
+  let infoSpy: jest.Mock;
+  let addPathSpy: jest.Mock;
+  let exportVariableSpy: jest.Mock;
+  let setOutputSpy: jest.Mock;
+  let tcFind: jest.Mock;
+  let spyExtractZip: jest.Mock;
+  let spyExtractTar: jest.Mock;
+  let spyHttpClient: jest.SpiedFunction<typeof HttpClient.prototype.getJson>;
+  let spyExistsSync: jest.SpiedFunction<typeof fs.existsSync>;
+  let spyExec: jest.Mock;
+  let spySymlinkSync: jest.SpiedFunction<typeof fs.symlinkSync>;
+  let spyDownloadTool: jest.Mock;
+  let spyReadExactPyPyVersion: jest.Mock;
+  let spyFsReadDir: jest.SpiedFunction<typeof fs.readdirSync>;
+  let spyWriteExactPyPyVersionFile: jest.Mock;
+  let spyCacheDir: jest.Mock;
+  let spyChmodSync: jest.SpiedFunction<typeof fs.chmodSync>;
+  let spyCoreAddPath: jest.Mock;
+  let spyCoreExportVariable: jest.Mock;
  const env = process.env;

  beforeEach(() => {
-    getBooleanInputSpy = jest.spyOn(core, 'getBooleanInput');
+    getBooleanInputSpy = core.getBooleanInput as jest.Mock;
    getBooleanInputSpy.mockImplementation(() => false);

-    infoSpy = jest.spyOn(core, 'info');
+    infoSpy = core.info as jest.Mock;
    infoSpy.mockImplementation(() => {});

-    warningSpy = jest.spyOn(core, 'warning');
+    warningSpy = core.warning as jest.Mock;
    warningSpy.mockImplementation(() => null);

-    debugSpy = jest.spyOn(core, 'debug');
+    debugSpy = core.debug as jest.Mock;
    debugSpy.mockImplementation(() => null);

-    addPathSpy = jest.spyOn(core, 'addPath');
+    addPathSpy = core.addPath as jest.Mock;
    addPathSpy.mockImplementation(() => null);

-    exportVariableSpy = jest.spyOn(core, 'exportVariable');
+    exportVariableSpy = core.exportVariable as jest.Mock;
    exportVariableSpy.mockImplementation(() => null);

-    setOutputSpy = jest.spyOn(core, 'setOutput');
+    setOutputSpy = core.setOutput as jest.Mock;
    setOutputSpy.mockImplementation(() => null);

-    jest.resetModules();
    process.env = {...env};
-    tcFind = jest.spyOn(tc, 'find');
-    tcFind.mockImplementation((tool: string, version: string) => {
-      const semverRange = new semver.Range(version);
-      let pypyPath = '';
-      if (semver.satisfies('3.6.12', semverRange)) {
-        pypyPath = path.join(toolDir, 'PyPy', '3.6.12', architecture);
+    tcFind = tc.find as jest.Mock;
+    (tcFind as jest.Mock<typeof tc.find>).mockImplementation(
+      (tool: string, version: string) => {
+        const semverRange = new semver.Range(version);
+        let pypyPath = '';
+        if (semver.satisfies('3.6.12', semverRange)) {
+          pypyPath = path.join(toolDir, 'PyPy', '3.6.12', architecture);
+        }
+        return pypyPath;
      }
-      return pypyPath;
-    });
-
-    spyWriteExactPyPyVersionFile = jest.spyOn(
-      utils,
-      'writeExactPyPyVersionFile'
    );
+
+    spyWriteExactPyPyVersionFile = utils.writeExactPyPyVersionFile as jest.Mock;
    spyWriteExactPyPyVersionFile.mockImplementation(() => null);

-    spyReadExactPyPyVersion = jest.spyOn(utils, 'readExactPyPyVersionFile');
+    spyReadExactPyPyVersion = utils.readExactPyPyVersionFile as jest.Mock;
    spyReadExactPyPyVersion.mockImplementation(() => '7.3.3');

-    spyDownloadTool = jest.spyOn(tc, 'downloadTool');
+    spyDownloadTool = tc.downloadTool as jest.Mock;
    spyDownloadTool.mockImplementation(() => path.join(tempDir, 'PyPy'));

-    spyExtractZip = jest.spyOn(tc, 'extractZip');
+    spyExtractZip = tc.extractZip as jest.Mock;
    spyExtractZip.mockImplementation(() => tempDir);

-    spyExtractTar = jest.spyOn(tc, 'extractTar');
+    spyExtractTar = tc.extractTar as jest.Mock;
    spyExtractTar.mockImplementation(() => tempDir);

    spyFsReadDir = jest.spyOn(fs, 'readdirSync');
-    spyFsReadDir.mockImplementation((directory: string) => ['PyPyTest']);
+    spyFsReadDir.mockImplementation(() => ['PyPyTest'] as any);

    spyHttpClient = jest.spyOn(HttpClient.prototype, 'getJson');
    spyHttpClient.mockImplementation(
@@ -250,7 +310,7 @@ describe('findPyPyVersion', () => {
      }
    );

-    spyExec = jest.spyOn(exec, 'exec');
+    spyExec = exec.exec as jest.Mock;
    spyExec.mockImplementation(() => undefined);

    spySymlinkSync = jest.spyOn(fs, 'symlinkSync');
@@ -259,9 +319,9 @@ describe('findPyPyVersion', () => {
    spyExistsSync = jest.spyOn(fs, 'existsSync');
    spyExistsSync.mockReturnValue(true);

-    spyCoreAddPath = jest.spyOn(core, 'addPath');
+    spyCoreAddPath = core.addPath as jest.Mock;

-    spyCoreExportVariable = jest.spyOn(core, 'exportVariable');
+    spyCoreExportVariable = core.exportVariable as jest.Mock;
  });

  afterEach(() => {
@@ -308,7 +368,7 @@ describe('findPyPyVersion', () => {
  });

  it('found and install successfully', async () => {
-    spyCacheDir = jest.spyOn(tc, 'cacheDir');
+    spyCacheDir = tc.cacheDir as jest.Mock;
    spyCacheDir.mockImplementation(() =>
      path.join(toolDir, 'PyPy', '3.7.7', architecture)
    );
@@ -338,7 +398,7 @@ describe('findPyPyVersion', () => {
  });

  it('found and install successfully without environment update', async () => {
-    spyCacheDir = jest.spyOn(tc, 'cacheDir');
+    spyCacheDir = tc.cacheDir as jest.Mock;
    spyCacheDir.mockImplementation(() =>
      path.join(toolDir, 'PyPy', '3.7.7', architecture)
    );
@@ -394,7 +454,7 @@ describe('findPyPyVersion', () => {
  });

  it('check-latest enabled version found and install successfully', async () => {
-    spyCacheDir = jest.spyOn(tc, 'cacheDir');
+    spyCacheDir = tc.cacheDir as jest.Mock;
    spyCacheDir.mockImplementation(() =>
      path.join(toolDir, 'PyPy', '3.7.7', architecture)
    );
@@ -418,14 +478,16 @@ describe('findPyPyVersion', () => {
  });

  it('check-latest enabled version is not found and used from toolcache', async () => {
-    tcFind.mockImplementationOnce((tool: string, version: string) => {
-      const semverRange = new semver.Range(version);
-      let pypyPath = '';
-      if (semver.satisfies('3.8.8', semverRange)) {
-        pypyPath = path.join(toolDir, 'PyPy', '3.8.8', architecture);
+    (tcFind as jest.Mock<typeof tc.find>).mockImplementationOnce(
+      (tool: string, version: string) => {
+        const semverRange = new semver.Range(version);
+        let pypyPath = '';
+        if (semver.satisfies('3.8.8', semverRange)) {
+          pypyPath = path.join(toolDir, 'PyPy', '3.8.8', architecture);
+        }
+        return pypyPath;
      }
-      return pypyPath;
-    });
+    );
    await expect(
      finder.findPyPyVersion(
        'pypy-3.8-v7.3.x',
@@ -445,7 +507,7 @@ describe('findPyPyVersion', () => {
  });

  it('found and install successfully, pre-release fallback', async () => {
-    spyCacheDir = jest.spyOn(tc, 'cacheDir');
+    spyCacheDir = tc.cacheDir as jest.Mock;
    spyCacheDir.mockImplementation(() =>
      path.join(toolDir, 'PyPy', '3.8.12', architecture)
    );
@@ -1,4 +1,5 @@
-import {desugarVersion, pythonVersionToSemantic} from '../src/find-python';
+import {describe, it, expect} from '@jest/globals';
+import {desugarVersion, pythonVersionToSemantic} from '../src/find-python.js';

 describe('desugarVersion', () => {
  it.each([
@@ -1,8 +1,12 @@
+import {jest, describe, it, expect, beforeEach, afterEach} from '@jest/globals';
+import {fileURLToPath} from 'url';
 import * as io from '@actions/io';
 import os from 'os';
 import fs from 'fs';
 import path from 'path';

+const __dirname = path.dirname(fileURLToPath(import.meta.url));
+
 const toolDir = path.join(
  __dirname,
  'runner',
@@ -19,26 +23,78 @@ const tempDir = path.join(
 process.env['RUNNER_TOOL_CACHE'] = toolDir;
 process.env['RUNNER_TEMP'] = tempDir;

-import * as tc from '@actions/tool-cache';
-import * as core from '@actions/core';
-import * as finder from '../src/find-python';
-import * as installer from '../src/install-python';
+// Mock @actions modules
+jest.unstable_mockModule('@actions/core', () => ({
+  info: jest.fn(),
+  warning: jest.fn(),
+  debug: jest.fn(),
+  error: jest.fn(),
+  notice: jest.fn(),
+  setFailed: jest.fn(),
+  setOutput: jest.fn(),
+  getInput: jest.fn(),
+  getBooleanInput: jest.fn(),
+  getMultilineInput: jest.fn(),
+  addPath: jest.fn(),
+  exportVariable: jest.fn(),
+  saveState: jest.fn(),
+  getState: jest.fn(),
+  setSecret: jest.fn(),
+  isDebug: jest.fn(() => false),
+  startGroup: jest.fn(),
+  endGroup: jest.fn(),
+  group: jest.fn((_name: string, fn: () => Promise<unknown>) => fn()),
+  toPlatformPath: jest.fn((p: string) => p),
+  toWin32Path: jest.fn((p: string) => p),
+  toPosixPath: jest.fn((p: string) => p)
+}));

-import manifestData from './data/versions-manifest.json';
+// Pre-import real @actions/tool-cache before any mocks
+const realTc = await import('@actions/tool-cache');
+
+jest.unstable_mockModule('@actions/tool-cache', () => ({
+  ...realTc,
+  find: jest.fn(realTc.find),
+  getManifestFromRepo: jest.fn()
+}));
+
+jest.unstable_mockModule('@actions/exec', () => ({
+  exec: jest.fn(),
+  getExecOutput: jest.fn()
+}));
+
+// Pre-import real install-python AFTER all its dependency mocks are registered
+// so it captures the mocked @actions/tool-cache, @actions/core, @actions/exec
+const realInstaller = await import('../src/install-python.js');
+
+// Mock local install-python module - keep real getManifest/findReleaseFromManifest
+jest.unstable_mockModule('../src/install-python.js', () => ({
+  ...realInstaller,
+  installCpythonFromRelease: jest.fn()
+}));
+
+// Dynamic imports after mocking
+const core = await import('@actions/core');
+const tc = await import('@actions/tool-cache');
+const finder = await import('../src/find-python.js');
+const installer = await import('../src/install-python.js');
+
+import manifestData from './data/versions-manifest.json' with {type: 'json'};

 describe('Finder tests', () => {
-  let writeSpy: jest.SpyInstance;
-  let spyCoreAddPath: jest.SpyInstance;
-  let spyCoreExportVariable: jest.SpyInstance;
+  let writeSpy: jest.SpiedFunction<typeof process.stdout.write>;
+  let spyCoreAddPath: jest.Mock;
+  let spyCoreExportVariable: jest.Mock;
  const env = process.env;

  beforeEach(() => {
    writeSpy = jest.spyOn(process.stdout, 'write');
-    writeSpy.mockImplementation(() => {});
-    jest.resetModules();
+    writeSpy.mockImplementation(() => true);
    process.env = {...env};
-    spyCoreAddPath = jest.spyOn(core, 'addPath');
-    spyCoreExportVariable = jest.spyOn(core, 'exportVariable');
+    spyCoreAddPath = core.addPath as jest.Mock;
+    spyCoreExportVariable = core.exportVariable as jest.Mock;
+    // Restore real tc.find default (cleared by jest.resetAllMocks)
+    (tc.find as jest.Mock).mockImplementation(realTc.find as any);
  });

  afterEach(() => {
@@ -49,8 +105,8 @@ describe('Finder tests', () => {
  });

  it('Finds Python if it is installed', async () => {
-    const getBooleanInputSpy = jest.spyOn(core, 'getBooleanInput');
-    getBooleanInputSpy.mockImplementation(input => false);
+    const getBooleanInputSpy = core.getBooleanInput as jest.Mock;
+    getBooleanInputSpy.mockImplementation(() => false);

    const pythonDir: string = path.join(toolDir, 'Python', '3.0.0', 'x64');
    await io.mkdirP(pythonDir);
@@ -79,16 +135,13 @@ describe('Finder tests', () => {
  });

  it('Finds stable Python version if it is not installed, but exists in the manifest', async () => {
-    const findSpy: jest.SpyInstance = jest.spyOn(tc, 'getManifestFromRepo');
-    findSpy.mockImplementation(() => <tc.IToolRelease[]>manifestData);
+    const findSpy = tc.getManifestFromRepo as jest.Mock;
+    findSpy.mockImplementation(() => manifestData);

-    const getBooleanInputSpy = jest.spyOn(core, 'getBooleanInput');
-    getBooleanInputSpy.mockImplementation(input => false);
+    const getBooleanInputSpy = core.getBooleanInput as jest.Mock;
+    getBooleanInputSpy.mockImplementation(() => false);

-    const installSpy: jest.SpyInstance = jest.spyOn(
-      installer,
-      'installCpythonFromRelease'
-    );
+    const installSpy = installer.installCpythonFromRelease as jest.Mock;
    installSpy.mockImplementation(async () => {
      const pythonDir: string = path.join(toolDir, 'Python', '1.2.3', 'x64');
      await io.mkdirP(pythonDir);
@@ -113,16 +166,13 @@ describe('Finder tests', () => {
  });

  it('Finds pre-release Python version in the manifest', async () => {
-    const findSpy: jest.SpyInstance = jest.spyOn(tc, 'getManifestFromRepo');
-    findSpy.mockImplementation(() => <tc.IToolRelease[]>manifestData);
+    const findSpy = tc.getManifestFromRepo as jest.Mock;
+    findSpy.mockImplementation(() => manifestData);

-    const getBooleanInputSpy = jest.spyOn(core, 'getBooleanInput');
-    getBooleanInputSpy.mockImplementation(input => false);
+    const getBooleanInputSpy = core.getBooleanInput as jest.Mock;
+    getBooleanInputSpy.mockImplementation(() => false);

-    const installSpy: jest.SpyInstance = jest.spyOn(
-      installer,
-      'installCpythonFromRelease'
-    );
+    const installSpy = installer.installCpythonFromRelease as jest.Mock;
    installSpy.mockImplementation(async () => {
      const pythonDir: string = path.join(
        toolDir,
@@ -150,40 +200,34 @@ describe('Finder tests', () => {
  });

  it('Check-latest true, finds the latest version in the manifest', async () => {
-    const findSpy: jest.SpyInstance = jest.spyOn(tc, 'getManifestFromRepo');
-    findSpy.mockImplementation(() => <tc.IToolRelease[]>manifestData);
+    const findSpy = tc.getManifestFromRepo as jest.Mock;
+    findSpy.mockImplementation(() => manifestData);

-    const getBooleanInputSpy = jest.spyOn(core, 'getBooleanInput');
-    getBooleanInputSpy.mockImplementation(input => true);
+    const getBooleanInputSpy = core.getBooleanInput as jest.Mock;
+    getBooleanInputSpy.mockImplementation(() => true);

-    const cnSpy: jest.SpyInstance = jest.spyOn(process.stdout, 'write');
-    cnSpy.mockImplementation(line => {
-      // uncomment to debug
-      // process.stderr.write('write:' + line + '\n');
-    });
+    const cnSpy = jest.spyOn(process.stdout, 'write');
+    cnSpy.mockImplementation(() => true);

-    const addPathSpy: jest.SpyInstance = jest.spyOn(core, 'addPath');
+    const addPathSpy = core.addPath as jest.Mock;
    addPathSpy.mockImplementation(() => null);

-    const infoSpy: jest.SpyInstance = jest.spyOn(core, 'info');
+    const infoSpy = core.info as jest.Mock;
    infoSpy.mockImplementation(() => {});

-    const debugSpy: jest.SpyInstance = jest.spyOn(core, 'debug');
+    const debugSpy = core.debug as jest.Mock;
    debugSpy.mockImplementation(() => {});

    const pythonDir: string = path.join(toolDir, 'Python', '1.2.2', 'x64');
    const expPath: string = path.join(toolDir, 'Python', '1.2.3', 'x64');

-    const installSpy: jest.SpyInstance = jest.spyOn(
-      installer,
-      'installCpythonFromRelease'
-    );
+    const installSpy = installer.installCpythonFromRelease as jest.Mock;
    installSpy.mockImplementation(async () => {
      await io.mkdirP(expPath);
      fs.writeFileSync(`${expPath}.complete`, 'hello');
    });

-    const tcFindSpy: jest.SpyInstance = jest.spyOn(tc, 'find');
+    const tcFindSpy = tc.find as jest.Mock;
    tcFindSpy
      .mockImplementationOnce(() => '')
      .mockImplementationOnce(() => expPath);
@@ -224,13 +268,10 @@ describe('Finder tests', () => {
  });

  it('Finds stable Python version if it is not installed, but exists in the manifest, skipping newer pre-release', async () => {
-    const findSpy: jest.SpyInstance = jest.spyOn(tc, 'getManifestFromRepo');
-    findSpy.mockImplementation(() => <tc.IToolRelease[]>manifestData);
+    const findSpy = tc.getManifestFromRepo as jest.Mock;
+    findSpy.mockImplementation(() => manifestData);

-    const installSpy: jest.SpyInstance = jest.spyOn(
-      installer,
-      'installCpythonFromRelease'
-    );
+    const installSpy = installer.installCpythonFromRelease as jest.Mock;
    installSpy.mockImplementation(async () => {
      const pythonDir: string = path.join(toolDir, 'Python', '1.2.3', 'x64');
      await io.mkdirP(pythonDir);
@@ -246,13 +287,10 @@ describe('Finder tests', () => {
  });

  it('Finds Python version if it is not installed, but exists in the manifest, pre-release fallback', async () => {
-    const findSpy: jest.SpyInstance = jest.spyOn(tc, 'getManifestFromRepo');
-    findSpy.mockImplementation(() => <tc.IToolRelease[]>manifestData);
+    const findSpy = tc.getManifestFromRepo as jest.Mock;
+    findSpy.mockImplementation(() => manifestData);

-    const installSpy: jest.SpyInstance = jest.spyOn(
-      installer,
-      'installCpythonFromRelease'
-    );
+    const installSpy = installer.installCpythonFromRelease as jest.Mock;
    installSpy.mockImplementation(async () => {
      const pythonDir: string = path.join(
        toolDir,
@@ -1,20 +1,75 @@
+import {jest, describe, it, expect, beforeEach, afterEach} from '@jest/globals';
+import {fileURLToPath} from 'url';
 import fs from 'fs';
-
-import {HttpClient} from '@actions/http-client';
-import * as ifm from '@actions/http-client/lib/interfaces';
-import * as tc from '@actions/tool-cache';
-import * as exec from '@actions/exec';
-import * as core from '@actions/core';
 import * as path from 'path';

-import * as installer from '../src/install-graalpy';
-import {
-  IGraalPyManifestRelease,
-  IGraalPyManifestAsset,
-  IS_WINDOWS
-} from '../src/utils';
+const __dirname = path.dirname(fileURLToPath(import.meta.url));

-import manifestData from './data/graalpy.json';
+// Mock @actions modules
+jest.unstable_mockModule('@actions/core', () => ({
+  info: jest.fn(),
+  warning: jest.fn(),
+  debug: jest.fn(),
+  error: jest.fn(),
+  notice: jest.fn(),
+  setFailed: jest.fn(),
+  setOutput: jest.fn(),
+  getInput: jest.fn(),
+  getBooleanInput: jest.fn(),
+  getMultilineInput: jest.fn(),
+  addPath: jest.fn(),
+  exportVariable: jest.fn(),
+  saveState: jest.fn(),
+  getState: jest.fn(),
+  setSecret: jest.fn(),
+  isDebug: jest.fn(() => false),
+  startGroup: jest.fn(),
+  endGroup: jest.fn(),
+  group: jest.fn((_name: string, fn: () => Promise<unknown>) => fn()),
+  toPlatformPath: jest.fn((p: string) => p),
+  toWin32Path: jest.fn((p: string) => p),
+  toPosixPath: jest.fn((p: string) => p)
+}));
+
+jest.unstable_mockModule('@actions/tool-cache', () => ({
+  find: jest.fn(),
+  findAllVersions: jest.fn(),
+  downloadTool: jest.fn(),
+  extractZip: jest.fn(),
+  extractTar: jest.fn(),
+  extract7z: jest.fn(),
+  extractXar: jest.fn(),
+  cacheDir: jest.fn(),
+  cacheFile: jest.fn(),
+  getManifestFromRepo: jest.fn(),
+  findFromManifest: jest.fn(),
+  evaluateVersions: jest.fn()
+}));
+
+jest.unstable_mockModule('@actions/exec', () => ({
+  exec: jest.fn(),
+  getExecOutput: jest.fn()
+}));
+
+// Dynamic imports after mocking
+const core = await import('@actions/core');
+const tc = await import('@actions/tool-cache');
+const exec = await import('@actions/exec');
+
+// Non-mocked imports
+import {HttpClient} from '@actions/http-client';
+import type * as ifm from '@actions/http-client/lib/interfaces';
+
+const installer = await import('../src/install-graalpy.js');
+const utils = await import('../src/utils.js');
+
+import type {
+  IGraalPyManifestRelease,
+  IGraalPyManifestAsset
+} from '../src/utils.js';
+import manifestData from './data/graalpy.json' with {type: 'json'};
+
+const IS_WINDOWS = utils.IS_WINDOWS;

 const architecture = 'x64';

@@ -48,18 +103,18 @@ describe('findRelease', () => {
    browser_download_url: `https://github.com/graalvm/graal-languages-ea-builds/releases/download/graalpy-24.1.0-ea.09/graalpy-24.1.0-ea.09-${extensionName}`
  };

-  let warningSpy: jest.SpyInstance;
-  let debugSpy: jest.SpyInstance;
-  let infoSpy: jest.SpyInstance;
+  let warningSpy: jest.Mock;
+  let debugSpy: jest.Mock;
+  let infoSpy: jest.Mock;

  beforeEach(() => {
-    infoSpy = jest.spyOn(core, 'info');
+    infoSpy = core.info as jest.Mock;
    infoSpy.mockImplementation(() => {});

-    warningSpy = jest.spyOn(core, 'warning');
+    warningSpy = core.warning as jest.Mock;
    warningSpy.mockImplementation(() => null);

-    debugSpy = jest.spyOn(core, 'debug');
+    debugSpy = core.debug as jest.Mock;
    debugSpy.mockImplementation(() => null);
  });

@@ -115,51 +170,57 @@ describe('findRelease', () => {
      resolvedGraalPyVersion: '24.1.0-ea.9'
    });
  });
+
+  afterEach(() => {
+    jest.resetAllMocks();
+    jest.clearAllMocks();
+    jest.restoreAllMocks();
+  });
 });

 describe('installGraalPy', () => {
-  let tcFind: jest.SpyInstance;
-  let warningSpy: jest.SpyInstance;
-  let debugSpy: jest.SpyInstance;
-  let infoSpy: jest.SpyInstance;
-  let spyExtractZip: jest.SpyInstance;
-  let spyExtractTar: jest.SpyInstance;
-  let spyFsReadDir: jest.SpyInstance;
-  let spyFsWriteFile: jest.SpyInstance;
-  let spyHttpClient: jest.SpyInstance;
-  let spyExistsSync: jest.SpyInstance;
-  let spyExec: jest.SpyInstance;
-  let spySymlinkSync: jest.SpyInstance;
-  let spyDownloadTool: jest.SpyInstance;
-  let spyCacheDir: jest.SpyInstance;
-  let spyChmodSync: jest.SpyInstance;
+  let tcFind: jest.Mock;
+  let infoSpy: jest.Mock;
+  let warningSpy: jest.Mock;
+  let debugSpy: jest.Mock;
+  let spyExtractZip: jest.Mock;
+  let spyExtractTar: jest.Mock;
+  let spyFsReadDir: jest.SpiedFunction<typeof fs.readdirSync>;
+  let spyFsWriteFile: jest.SpiedFunction<typeof fs.writeFileSync>;
+  let spyHttpClient: jest.SpiedFunction<typeof HttpClient.prototype.getJson>;
+  let spyExistsSync: jest.SpiedFunction<typeof fs.existsSync>;
+  let spyExec: jest.Mock;
+  let spySymlinkSync: jest.SpiedFunction<typeof fs.symlinkSync>;
+  let spyDownloadTool: jest.Mock;
+  let spyCacheDir: jest.Mock;
+  let spyChmodSync: jest.SpiedFunction<typeof fs.chmodSync>;

  beforeEach(() => {
-    tcFind = jest.spyOn(tc, 'find');
+    tcFind = tc.find as jest.Mock;
    tcFind.mockImplementation(() =>
      path.join('GraalPy', '3.6.12', architecture)
    );

-    spyDownloadTool = jest.spyOn(tc, 'downloadTool');
+    spyDownloadTool = tc.downloadTool as jest.Mock;
    spyDownloadTool.mockImplementation(() => path.join(tempDir, 'GraalPy'));

-    spyExtractZip = jest.spyOn(tc, 'extractZip');
+    spyExtractZip = tc.extractZip as jest.Mock;
    spyExtractZip.mockImplementation(() => tempDir);

-    spyExtractTar = jest.spyOn(tc, 'extractTar');
+    spyExtractTar = tc.extractTar as jest.Mock;
    spyExtractTar.mockImplementation(() => tempDir);

-    infoSpy = jest.spyOn(core, 'info');
+    infoSpy = core.info as jest.Mock;
    infoSpy.mockImplementation(() => {});

-    warningSpy = jest.spyOn(core, 'warning');
+    warningSpy = core.warning as jest.Mock;
    warningSpy.mockImplementation(() => null);

-    debugSpy = jest.spyOn(core, 'debug');
+    debugSpy = core.debug as jest.Mock;
    debugSpy.mockImplementation(() => null);

    spyFsReadDir = jest.spyOn(fs, 'readdirSync');
-    spyFsReadDir.mockImplementation(() => ['GraalPyTest']);
+    spyFsReadDir.mockImplementation(() => ['GraalPyTest'] as any);

    spyFsWriteFile = jest.spyOn(fs, 'writeFileSync');
    spyFsWriteFile.mockImplementation(() => undefined);
@@ -176,7 +237,7 @@ describe('installGraalPy', () => {
      }
    );

-    spyExec = jest.spyOn(exec, 'exec');
+    spyExec = exec.exec as jest.Mock;
    spyExec.mockImplementation(() => undefined);

    spySymlinkSync = jest.spyOn(fs, 'symlinkSync');
@@ -205,7 +266,7 @@ describe('installGraalPy', () => {
  });

  it('found and install GraalPy', async () => {
-    spyCacheDir = jest.spyOn(tc, 'cacheDir');
+    spyCacheDir = tc.cacheDir as jest.Mock;
    spyCacheDir.mockImplementation(() =>
      path.join(toolDir, 'GraalPy', '21.3.0', architecture)
    );
@@ -227,7 +288,7 @@ describe('installGraalPy', () => {
  });

  it('found and install GraalPy, pre-release fallback', async () => {
-    spyCacheDir = jest.spyOn(tc, 'cacheDir');
+    spyCacheDir = tc.cacheDir as jest.Mock;
    spyCacheDir.mockImplementation(() =>
      path.join(toolDir, 'GraalPy', '24.1.0', architecture)
    );
@@ -1,20 +1,72 @@
+import {jest, describe, it, expect, beforeEach, afterEach} from '@jest/globals';
+import {fileURLToPath} from 'url';
 import fs from 'fs';
-
-import {HttpClient} from '@actions/http-client';
-import * as ifm from '@actions/http-client/lib/interfaces';
-import * as tc from '@actions/tool-cache';
-import * as exec from '@actions/exec';
-import * as core from '@actions/core';
 import * as path from 'path';

-import * as installer from '../src/install-pypy';
-import {
-  IPyPyManifestRelease,
-  IPyPyManifestAsset,
-  IS_WINDOWS
-} from '../src/utils';
+const __dirname = path.dirname(fileURLToPath(import.meta.url));

-import manifestData from './data/pypy.json';
+// Mock @actions modules
+jest.unstable_mockModule('@actions/core', () => ({
+  info: jest.fn(),
+  warning: jest.fn(),
+  debug: jest.fn(),
+  error: jest.fn(),
+  notice: jest.fn(),
+  setFailed: jest.fn(),
+  setOutput: jest.fn(),
+  getInput: jest.fn(),
+  getBooleanInput: jest.fn(),
+  getMultilineInput: jest.fn(),
+  addPath: jest.fn(),
+  exportVariable: jest.fn(),
+  saveState: jest.fn(),
+  getState: jest.fn(),
+  setSecret: jest.fn(),
+  isDebug: jest.fn(() => false),
+  startGroup: jest.fn(),
+  endGroup: jest.fn(),
+  group: jest.fn((_name: string, fn: () => Promise<unknown>) => fn()),
+  toPlatformPath: jest.fn((p: string) => p),
+  toWin32Path: jest.fn((p: string) => p),
+  toPosixPath: jest.fn((p: string) => p)
+}));
+
+jest.unstable_mockModule('@actions/tool-cache', () => ({
+  find: jest.fn(),
+  findAllVersions: jest.fn(),
+  downloadTool: jest.fn(),
+  extractZip: jest.fn(),
+  extractTar: jest.fn(),
+  extract7z: jest.fn(),
+  extractXar: jest.fn(),
+  cacheDir: jest.fn(),
+  cacheFile: jest.fn(),
+  getManifestFromRepo: jest.fn(),
+  findFromManifest: jest.fn(),
+  evaluateVersions: jest.fn()
+}));
+
+jest.unstable_mockModule('@actions/exec', () => ({
+  exec: jest.fn(),
+  getExecOutput: jest.fn()
+}));
+
+// Dynamic imports after mocking
+const core = await import('@actions/core');
+const tc = await import('@actions/tool-cache');
+const exec = await import('@actions/exec');
+
+// Non-mocked imports
+import {HttpClient} from '@actions/http-client';
+import type * as ifm from '@actions/http-client/lib/interfaces';
+
+const installer = await import('../src/install-pypy.js');
+const utils = await import('../src/utils.js');
+
+import type {IPyPyManifestRelease, IPyPyManifestAsset} from '../src/utils.js';
+import manifestData from './data/pypy.json' with {type: 'json'};
+
+const IS_WINDOWS = utils.IS_WINDOWS;

 let architecture: string;
 if (IS_WINDOWS) {
@@ -58,19 +110,18 @@ describe('findRelease', () => {
    download_url: `https://test.download.python.org/pypy/pypy3.6-v7.4.0rc1-${extensionName}`
  };

-  let getBooleanInputSpy: jest.SpyInstance;
-  let warningSpy: jest.SpyInstance;
-  let debugSpy: jest.SpyInstance;
-  let infoSpy: jest.SpyInstance;
+  let infoSpy: jest.Mock;
+  let warningSpy: jest.Mock;
+  let debugSpy: jest.Mock;

  beforeEach(() => {
-    infoSpy = jest.spyOn(core, 'info');
+    infoSpy = core.info as jest.Mock;
    infoSpy.mockImplementation(() => {});

-    warningSpy = jest.spyOn(core, 'warning');
+    warningSpy = core.warning as jest.Mock;
    warningSpy.mockImplementation(() => null);

-    debugSpy = jest.spyOn(core, 'debug');
+    debugSpy = core.debug as jest.Mock;
    debugSpy.mockImplementation(() => null);
  });

@@ -215,50 +266,55 @@ describe('findRelease', () => {
      resolvedPyPyVersion: pypyVersion
    });
  });
+
+  afterEach(() => {
+    jest.resetAllMocks();
+    jest.clearAllMocks();
+    jest.restoreAllMocks();
+  });
 });

 describe('installPyPy', () => {
-  let tcFind: jest.SpyInstance;
-  let getBooleanInputSpy: jest.SpyInstance;
-  let warningSpy: jest.SpyInstance;
-  let debugSpy: jest.SpyInstance;
-  let infoSpy: jest.SpyInstance;
-  let spyExtractZip: jest.SpyInstance;
-  let spyExtractTar: jest.SpyInstance;
-  let spyFsReadDir: jest.SpyInstance;
-  let spyFsWriteFile: jest.SpyInstance;
-  let spyHttpClient: jest.SpyInstance;
-  let spyExistsSync: jest.SpyInstance;
-  let spyExec: jest.SpyInstance;
-  let spySymlinkSync: jest.SpyInstance;
-  let spyDownloadTool: jest.SpyInstance;
-  let spyCacheDir: jest.SpyInstance;
-  let spyChmodSync: jest.SpyInstance;
+  let tcFind: jest.Mock;
+  let infoSpy: jest.Mock;
+  let warningSpy: jest.Mock;
+  let debugSpy: jest.Mock;
+  let spyExtractZip: jest.Mock;
+  let spyExtractTar: jest.Mock;
+  let spyFsReadDir: jest.SpiedFunction<typeof fs.readdirSync>;
+  let spyFsWriteFile: jest.SpiedFunction<typeof fs.writeFileSync>;
+  let spyHttpClient: jest.SpiedFunction<typeof HttpClient.prototype.getJson>;
+  let spyExistsSync: jest.SpiedFunction<typeof fs.existsSync>;
+  let spyExec: jest.Mock;
+  let spySymlinkSync: jest.SpiedFunction<typeof fs.symlinkSync>;
+  let spyDownloadTool: jest.Mock;
+  let spyCacheDir: jest.Mock;
+  let spyChmodSync: jest.SpiedFunction<typeof fs.chmodSync>;

  beforeEach(() => {
-    tcFind = jest.spyOn(tc, 'find');
+    tcFind = tc.find as jest.Mock;
    tcFind.mockImplementation(() => path.join('PyPy', '3.6.12', architecture));

-    spyDownloadTool = jest.spyOn(tc, 'downloadTool');
+    spyDownloadTool = tc.downloadTool as jest.Mock;
    spyDownloadTool.mockImplementation(() => path.join(tempDir, 'PyPy'));

-    spyExtractZip = jest.spyOn(tc, 'extractZip');
+    spyExtractZip = tc.extractZip as jest.Mock;
    spyExtractZip.mockImplementation(() => tempDir);

-    spyExtractTar = jest.spyOn(tc, 'extractTar');
+    spyExtractTar = tc.extractTar as jest.Mock;
    spyExtractTar.mockImplementation(() => tempDir);

-    infoSpy = jest.spyOn(core, 'info');
+    infoSpy = core.info as jest.Mock;
    infoSpy.mockImplementation(() => {});

-    warningSpy = jest.spyOn(core, 'warning');
+    warningSpy = core.warning as jest.Mock;
    warningSpy.mockImplementation(() => null);

-    debugSpy = jest.spyOn(core, 'debug');
+    debugSpy = core.debug as jest.Mock;
    debugSpy.mockImplementation(() => null);

    spyFsReadDir = jest.spyOn(fs, 'readdirSync');
-    spyFsReadDir.mockImplementation(() => ['PyPyTest']);
+    spyFsReadDir.mockImplementation(() => ['PyPyTest'] as any);

    spyFsWriteFile = jest.spyOn(fs, 'writeFileSync');
    spyFsWriteFile.mockImplementation(() => undefined);
@@ -275,7 +331,7 @@ describe('installPyPy', () => {
      }
    );

-    spyExec = jest.spyOn(exec, 'exec');
+    spyExec = exec.exec as jest.Mock;
    spyExec.mockImplementation(() => undefined);

    spySymlinkSync = jest.spyOn(fs, 'symlinkSync');
@@ -304,7 +360,7 @@ describe('installPyPy', () => {
  });

  it('found and install PyPy', async () => {
-    spyCacheDir = jest.spyOn(tc, 'cacheDir');
+    spyCacheDir = tc.cacheDir as jest.Mock;
    spyCacheDir.mockImplementation(() =>
      path.join(toolDir, 'PyPy', '3.6.12', architecture)
    );
@@ -328,7 +384,7 @@ describe('installPyPy', () => {
  });

  it('found and install PyPy, pre-release fallback', async () => {
-    spyCacheDir = jest.spyOn(tc, 'cacheDir');
+    spyCacheDir = tc.cacheDir as jest.Mock;
    spyCacheDir.mockImplementation(() =>
      path.join(toolDir, 'PyPy', '3.6.12', architecture)
    );
@@ -1,16 +1,76 @@
-import {
-  getManifest,
-  getManifestFromRepo,
-  getManifestFromURL
-} from '../src/install-python';
-import * as httpm from '@actions/http-client';
-import * as tc from '@actions/tool-cache';
+import {jest, describe, it, expect, beforeEach, afterEach} from '@jest/globals';

-jest.mock('@actions/http-client');
-jest.mock('@actions/tool-cache');
-jest.mock('@actions/tool-cache', () => ({
+class MockHttpClientError extends Error {
+  statusCode: number;
+  constructor(message: string, statusCode: number) {
+    super(message);
+    this.name = 'HttpClientError';
+    this.statusCode = statusCode;
+  }
+}
+
+// Mock @actions/http-client
+jest.unstable_mockModule('@actions/http-client', () => ({
+  HttpClient: jest.fn().mockImplementation(() => ({
+    getJson: jest.fn()
+  })),
+  HttpClientError: MockHttpClientError,
+  HttpCodes: {
+    OK: 200,
+    NotFound: 404,
+    InternalServerError: 500
+  }
+}));
+
+// Mock @actions/cache (needed transitively by utils.ts)
+jest.unstable_mockModule('@actions/cache', () => ({
+  saveCache: jest.fn(),
+  restoreCache: jest.fn(),
+  isFeatureAvailable: jest.fn()
+}));
+
+// Mock @actions/tool-cache
+jest.unstable_mockModule('@actions/tool-cache', () => ({
  getManifestFromRepo: jest.fn()
 }));
+
+// Mock @actions/core (needed by install-python.ts)
+jest.unstable_mockModule('@actions/core', () => ({
+  info: jest.fn(),
+  warning: jest.fn(),
+  debug: jest.fn(),
+  error: jest.fn(),
+  notice: jest.fn(),
+  setFailed: jest.fn(),
+  setOutput: jest.fn(),
+  getInput: jest.fn(),
+  getBooleanInput: jest.fn(),
+  getMultilineInput: jest.fn(),
+  addPath: jest.fn(),
+  exportVariable: jest.fn(),
+  saveState: jest.fn(),
+  getState: jest.fn(),
+  setSecret: jest.fn(),
+  isDebug: jest.fn(() => false),
+  startGroup: jest.fn(),
+  endGroup: jest.fn(),
+  group: jest.fn((_name: string, fn: () => Promise<unknown>) => fn()),
+  toPlatformPath: jest.fn((p: string) => p),
+  toWin32Path: jest.fn((p: string) => p),
+  toPosixPath: jest.fn((p: string) => p)
+}));
+
+// Mock @actions/exec (needed by install-python.ts)
+jest.unstable_mockModule('@actions/exec', () => ({
+  exec: jest.fn(),
+  getExecOutput: jest.fn()
+}));
+
+// Dynamic imports after mocking
+const httpm = await import('@actions/http-client');
+const tc = await import('@actions/tool-cache');
+const {getManifest, getManifestFromRepo, getManifestFromURL} =
+  await import('../src/install-python.js');
 const mockManifest = [
  {
    version: '1.0.0',
@@ -36,19 +96,19 @@ describe('getManifest', () => {
  });

  it('should return manifest from repo', async () => {
-    (tc.getManifestFromRepo as jest.Mock).mockResolvedValue(mockManifest);
+    (tc.getManifestFromRepo as jest.Mock<any>).mockResolvedValue(mockManifest);
    const manifest = await getManifest();
    expect(manifest).toEqual(mockManifest);
  });

  it('should return manifest from URL if repo fetch fails', async () => {
    jest.useFakeTimers();
-    (tc.getManifestFromRepo as jest.Mock).mockRejectedValue(
+    (tc.getManifestFromRepo as jest.Mock<any>).mockRejectedValue(
      new Error('Fetch failed')
    );
-    (httpm.HttpClient.prototype.getJson as jest.Mock).mockResolvedValue({
-      result: mockManifest
-    });
+    (httpm.HttpClient as jest.Mock<any>).mockImplementation(() => ({
+      getJson: jest.fn(async () => ({result: mockManifest}))
+    }));
    const promise = getManifest();
    await jest.runAllTimersAsync();
    const manifest = await promise;
@@ -57,10 +117,10 @@ describe('getManifest', () => {

  it('should fall back to URL if repo returns a truncated/empty manifest', async () => {
    jest.useFakeTimers();
-    (tc.getManifestFromRepo as jest.Mock).mockResolvedValue([]);
-    (httpm.HttpClient.prototype.getJson as jest.Mock).mockResolvedValue({
-      result: mockManifest
-    });
+    (tc.getManifestFromRepo as jest.Mock<any>).mockResolvedValue([]);
+    (httpm.HttpClient as jest.Mock<any>).mockImplementation(() => ({
+      getJson: jest.fn(async () => ({result: mockManifest}))
+    }));
    const promise = getManifest();
    await jest.runAllTimersAsync();
    const manifest = await promise;
@@ -69,22 +129,22 @@ describe('getManifest', () => {

  it('should retry on a transient invalid manifest and then succeed', async () => {
    jest.useFakeTimers();
-    (tc.getManifestFromRepo as jest.Mock)
+    (tc.getManifestFromRepo as jest.Mock<any>)
      .mockResolvedValueOnce([])
      .mockResolvedValueOnce(mockManifest);
    const promise = getManifest();
    await jest.runAllTimersAsync();
    const manifest = await promise;
    expect(manifest).toEqual(mockManifest);
-    expect(tc.getManifestFromRepo as jest.Mock).toHaveBeenCalledTimes(2);
+    expect(tc.getManifestFromRepo as jest.Mock<any>).toHaveBeenCalledTimes(2);
  });

  it('should fail loudly when the manifest is truncated/empty on every source', async () => {
    jest.useFakeTimers();
-    (tc.getManifestFromRepo as jest.Mock).mockResolvedValue([]);
-    (httpm.HttpClient.prototype.getJson as jest.Mock).mockResolvedValue({
-      result: []
-    });
+    (tc.getManifestFromRepo as jest.Mock<any>).mockResolvedValue([]);
+    (httpm.HttpClient as jest.Mock<any>).mockImplementation(() => ({
+      getJson: jest.fn(async () => ({result: []}))
+    }));
    const promise = getManifest();
    // Prevent unhandled rejection before timers advance.
    const catchPromise = promise.catch(() => {});
@@ -99,37 +159,47 @@ describe('getManifest', () => {
    const rateLimitError = Object.assign(new Error('API rate limit exceeded'), {
      httpStatusCode: 403
    });
-    (tc.getManifestFromRepo as jest.Mock).mockRejectedValue(rateLimitError);
-    (httpm.HttpClient.prototype.getJson as jest.Mock).mockResolvedValue({
-      result: mockManifest
-    });
+    (tc.getManifestFromRepo as jest.Mock<any>).mockRejectedValue(
+      rateLimitError
+    );
+    (httpm.HttpClient as jest.Mock<any>).mockImplementation(() => ({
+      getJson: jest.fn(async () => ({result: mockManifest}))
+    }));
    const manifest = await getManifest();
    expect(manifest).toEqual(mockManifest);
-    expect(tc.getManifestFromRepo as jest.Mock).toHaveBeenCalledTimes(1);
+    expect(tc.getManifestFromRepo as jest.Mock<any>).toHaveBeenCalledTimes(1);
  });
 });

 describe('getManifestFromRepo', () => {
+  beforeEach(() => {
+    jest.resetAllMocks();
+  });
+
  it('should return manifest from repo', async () => {
-    (tc.getManifestFromRepo as jest.Mock).mockResolvedValue(mockManifest);
+    (tc.getManifestFromRepo as jest.Mock<any>).mockResolvedValue(mockManifest);
    const manifest = await getManifestFromRepo();
    expect(manifest).toEqual(mockManifest);
  });
 });

 describe('getManifestFromURL', () => {
+  beforeEach(() => {
+    jest.resetAllMocks();
+  });
+
  it('should return manifest from URL', async () => {
-    (httpm.HttpClient.prototype.getJson as jest.Mock).mockResolvedValue({
-      result: mockManifest
-    });
+    (httpm.HttpClient as jest.Mock<any>).mockImplementation(() => ({
+      getJson: jest.fn(async () => ({result: mockManifest}))
+    }));
    const manifest = await getManifestFromURL();
    expect(manifest).toEqual(mockManifest);
  });

  it('should throw error if unable to get manifest from URL', async () => {
-    (httpm.HttpClient.prototype.getJson as jest.Mock).mockResolvedValue({
-      result: null
-    });
+    (httpm.HttpClient as jest.Mock<any>).mockImplementation(() => ({
+      getJson: jest.fn(async () => ({result: null}))
+    }));
    await expect(getManifestFromURL()).rejects.toThrow(
      'Unable to get manifest from'
    );
@@ -1,11 +1,57 @@
-import * as cache from '@actions/cache';
-import * as core from '@actions/core';
+import {
+  jest,
+  describe,
+  it,
+  expect,
+  afterAll,
+  afterEach,
+  beforeEach
+} from '@jest/globals';
+import {fileURLToPath} from 'url';
+import path from 'path';
+
+const __dirname = path.dirname(fileURLToPath(import.meta.url));
+
+// Mock @actions/cache
+jest.unstable_mockModule('@actions/cache', () => ({
+  isFeatureAvailable: jest.fn(),
+  saveCache: jest.fn(),
+  restoreCache: jest.fn()
+}));
+
+// Mock @actions/core
+jest.unstable_mockModule('@actions/core', () => ({
+  getInput: jest.fn(),
+  getBooleanInput: jest.fn(),
+  getMultilineInput: jest.fn(),
+  setOutput: jest.fn(),
+  setFailed: jest.fn(),
+  warning: jest.fn(),
+  info: jest.fn(),
+  debug: jest.fn(),
+  error: jest.fn(),
+  notice: jest.fn(),
+  startGroup: jest.fn(),
+  endGroup: jest.fn(),
+  addPath: jest.fn(),
+  exportVariable: jest.fn(),
+  saveState: jest.fn(),
+  getState: jest.fn(),
+  setSecret: jest.fn(),
+  isDebug: jest.fn(() => false),
+  group: jest.fn((_name: string, fn: () => Promise<unknown>) => fn()),
+  toPlatformPath: jest.fn((p: string) => p),
+  toWin32Path: jest.fn((p: string) => p),
+  toPosixPath: jest.fn((p: string) => p)
+}));
+
+const cache = await import('@actions/cache');
+const core = await import('@actions/core');
 import * as io from '@actions/io';

 import fs from 'fs';
-import path from 'path';

-import {
+const {
  validateVersion,
  validatePythonVersionFormatForPyPy,
  isCacheFeatureAvailable,
@@ -18,10 +64,7 @@ import {
  IS_WINDOWS,
  getDownloadFileName,
  getVersionInputFromToolVersions
-} from '../src/utils';
-
-jest.mock('@actions/cache');
-jest.mock('@actions/core');
+} = await import('../src/utils.js');

 describe('validatePythonVersionFormatForPyPy', () => {
  it.each([
@@ -55,8 +98,8 @@ describe('validateVersion', () => {

 describe('isCacheFeatureAvailable', () => {
  it('isCacheFeatureAvailable disabled on GHES', () => {
-    jest.spyOn(cache, 'isFeatureAvailable').mockImplementation(() => false);
-    const infoMock = jest.spyOn(core, 'warning');
+    (cache.isFeatureAvailable as jest.Mock).mockImplementation(() => false);
+    const infoMock = core.warning as jest.Mock;
    const message =
      'Caching is only supported on GHES version >= 3.5. If you are on a version >= 3.5, please check with your GHES admin if the Actions cache service is enabled or not.';
    try {
@@ -69,8 +112,8 @@ describe('isCacheFeatureAvailable', () => {
  });

  it('isCacheFeatureAvailable disabled on dotcom', () => {
-    jest.spyOn(cache, 'isFeatureAvailable').mockImplementation(() => false);
-    const infoMock = jest.spyOn(core, 'warning');
+    (cache.isFeatureAvailable as jest.Mock).mockImplementation(() => false);
+    const infoMock = core.warning as jest.Mock;
    const message =
      'The runner was not able to contact the cache service. Caching will be skipped';
    try {
@@ -83,9 +126,14 @@ describe('isCacheFeatureAvailable', () => {
  });

  it('isCacheFeatureAvailable is enabled', () => {
-    jest.spyOn(cache, 'isFeatureAvailable').mockImplementation(() => true);
+    (cache.isFeatureAvailable as jest.Mock).mockImplementation(() => true);
    expect(isCacheFeatureAvailable()).toBe(true);
  });
+
+  afterEach(() => {
+    jest.resetAllMocks();
+    jest.clearAllMocks();
+  });
 });

 const tempDir = path.join(
@@ -345,7 +393,6 @@ describe('isGhes', () => {
  const pristineEnv = process.env;

  beforeEach(() => {
-    jest.resetModules();
    process.env = {...pristineEnv};
  });

@@ -0,0 +1,3 @@
+{
+  "type": "module"
+}
@@ -0,0 +1,3 @@
+{
+  "type": "module"
+}
@@ -0,0 +1,74 @@
+// This is a reusable configuration file copied from https://github.com/actions/reusable-workflows/tree/main/reusable-configurations. Please don't make changes to this file as it's the subject of an automatic update.
+import js from '@eslint/js';
+import tsParser from '@typescript-eslint/parser';
+import tsPlugin from '@typescript-eslint/eslint-plugin';
+import jest from 'eslint-plugin-jest';
+import n from 'eslint-plugin-n';
+import prettier from 'eslint-config-prettier';
+import globals from 'globals';
+
+export default [
+  {
+    ignores: ['**/*', '!src/**', '!__tests__/**']
+  },
+  js.configs.recommended,
+  {
+    files: ['**/*.ts'],
+    languageOptions: {
+      parser: tsParser,
+      ecmaVersion: 2022,
+      sourceType: 'module',
+      globals: {
+        ...globals.node,
+        ...globals.es2015
+      }
+    },
+    plugins: {
+      '@typescript-eslint': tsPlugin,
+      n
+    },
+    rules: {
+      ...tsPlugin.configs.recommended.rules,
+      '@typescript-eslint/no-require-imports': 'error',
+      '@typescript-eslint/no-non-null-assertion': 'off',
+      '@typescript-eslint/no-explicit-any': 'off',
+      '@typescript-eslint/no-empty-function': 'off',
+      '@typescript-eslint/ban-ts-comment': [
+        'error',
+        {
+          'ts-ignore': 'allow-with-description'
+        }
+      ],
+      'no-console': 'error',
+      yoda: 'error',
+      'prefer-const': [
+        'error',
+        {
+          destructuring: 'all'
+        }
+      ],
+      'no-control-regex': 'off',
+      'no-constant-condition': ['error', {checkLoops: false}],
+      'no-undef': 'off',
+      'no-useless-assignment': 'off',
+      'n/no-extraneous-import': 'error'
+    }
+  },
+  {
+    files: ['**/*{test,spec}.ts'],
+    plugins: {jest},
+    languageOptions: {
+      globals: {
+        ...globals.jest
+      }
+    },
+    rules: {
+      ...jest.configs['flat/recommended'].rules,
+      '@typescript-eslint/no-unused-vars': 'off',
+      'jest/no-standalone-expect': 'off',
+      'jest/no-conditional-expect': 'off',
+      'no-console': 'off'
+    }
+  },
+  prettier
+];
@@ -1,11 +0,0 @@
-module.exports = {
-  clearMocks: true,
-  moduleFileExtensions: ['js', 'ts'],
-  testEnvironment: 'node',
-  testMatch: ['**/*.test.ts'],
-  testRunner: 'jest-circus/runner',
-  transform: {
-    '^.+\\.ts$': 'ts-jest'
-  },
-  verbose: true
-}
@@ -0,0 +1,24 @@
+export default {
+  clearMocks: true,
+  moduleFileExtensions: ['js', 'ts'],
+  roots: ['<rootDir>'],
+  testEnvironment: 'node',
+  testMatch: ['**/*.test.ts'],
+  transform: {
+    '^.+\\.ts$': [
+      'ts-jest',
+      {
+        useESM: true,
+        diagnostics: {
+          ignoreCodes: [151002]
+        }
+      }
+    ]
+  },
+  extensionsToTreatAsEsm: ['.ts'],
+  transformIgnorePatterns: ['node_modules/(?!(@actions)/)'],
+  moduleNameMapper: {
+    '^(\\.{1,2}/.*)\\.js$': '$1'
+  },
+  verbose: true
+}
@@ -1,6 +1,7 @@
 {
  "name": "setup-python",
-  "version": "6.3.0",
+  "version": "7.0.0",
+  "type": "module",
  "private": true,
  "description": "Setup python action",
  "main": "dist/index.js",
@@ -9,12 +10,12 @@
  },
  "scripts": {
    "build": "ncc build -o dist/setup src/setup-python.ts && ncc build -o dist/cache-save src/cache-save.ts",
-    "format": "prettier --no-error-on-unmatched-pattern --config ./.prettierrc.js --write \"**/*.{ts,yml,yaml}\"",
-    "format-check": "prettier --no-error-on-unmatched-pattern --config ./.prettierrc.js --check \"**/*.{ts,yml,yaml}\"",
-    "lint": "eslint --config ./.eslintrc.js \"**/*.ts\"",
-    "lint:fix": "eslint --config ./.eslintrc.js \"**/*.ts\" --fix",
+    "format": "prettier --no-error-on-unmatched-pattern --write \"**/*.{ts,yml,yaml}\"",
+    "format-check": "prettier --no-error-on-unmatched-pattern --check \"**/*.{ts,yml,yaml}\"",
+    "lint": "eslint \"**/*.ts\"",
+    "lint:fix": "eslint \"**/*.ts\" --fix",
    "release": "ncc build -o dist/setup src/setup-python.ts && ncc build -o dist/cache-save src/cache-save.ts && git add -f dist/",
-    "test": "jest --runInBand --coverage"
+    "test": "node --experimental-vm-modules ./node_modules/jest/bin/jest.js --runInBand --coverage"
  },
  "repository": {
    "type": "git",
@@ -28,34 +29,32 @@
  "author": "GitHub",
  "license": "MIT",
  "dependencies": {
-    "@actions/cache": "^5.1.0",
-    "@actions/core": "^2.0.3",
-    "@actions/exec": "^2.0.0",
-    "@actions/glob": "^0.5.1",
-    "@actions/http-client": "^3.0.2",
-    "@actions/io": "^2.0.0",
-    "@actions/tool-cache": "^3.0.1",
+    "@actions/cache": "^6.1.0",
+    "@actions/core": "^3.0.1",
+    "@actions/exec": "^3.0.0",
+    "@actions/glob": "^0.7.0",
+    "@actions/http-client": "^4.0.1",
+    "@actions/io": "^3.0.2",
+    "@actions/tool-cache": "^4.0.0",
    "@iarna/toml": "^3.0.0",
-    "semver": "^7.7.1"
+    "semver": "^7.8.5"
  },
  "devDependencies": {
-    "@types/jest": "^29.5.12",
+    "@eslint/js": "^10.0.1",
+    "@jest/globals": "^30.4.1",
    "@types/node": "^24.10.1",
    "@types/semver": "^7.7.0",
-    "@typescript-eslint/eslint-plugin": "^5.54.0",
-    "@typescript-eslint/parser": "^5.54.0",
-    "@vercel/ncc": "^0.38.3",
-    "eslint": "^8.57.0",
-    "eslint-config-prettier": "^8.6.0",
-    "eslint-plugin-jest": "^27.9.0",
-    "eslint-plugin-node": "^11.1.0",
-    "jest": "^29.7.0",
-    "jest-circus": "^29.7.0",
-    "prettier": "^3.6.2",
-    "ts-jest": "^29.3.2",
-    "typescript": "^5.9.3"
-  },
-  "overrides": {
-    "fast-xml-parser": "^5.9.2"
+    "@typescript-eslint/eslint-plugin": "^8.62.0",
+    "@typescript-eslint/parser": "^8.62.0",
+    "@vercel/ncc": "^0.44.0",
+    "eslint": "^10.5.0",
+    "eslint-config-prettier": "^10.0.0",
+    "eslint-plugin-jest": "^29.15.2",
+    "eslint-plugin-n": "^18.1.0",
+    "globals": "^17.7.0",
+    "jest": "^30.4.2",
+    "prettier": "^3.8.4",
+    "ts-jest": "^29.4.11",
+    "typescript": "^6.0.3"
  }
 }
@@ -1,7 +1,7 @@
 import * as cache from '@actions/cache';
 import * as core from '@actions/core';
-import {getOSInfo, IS_LINUX} from '../utils';
-import {CACHE_DEPENDENCY_BACKUP_PATH} from './constants';
+import {getOSInfo, IS_LINUX} from '../utils.js';
+import {CACHE_DEPENDENCY_BACKUP_PATH} from './constants.js';

 export enum State {
  STATE_CACHE_PRIMARY_KEY = 'cache-primary-key',
@@ -1,6 +1,6 @@
-import PipCache from './pip-cache';
-import PipenvCache from './pipenv-cache';
-import PoetryCache from './poetry-cache';
+import PipCache from './pip-cache.js';
+import PipenvCache from './pipenv-cache.js';
+import PoetryCache from './poetry-cache.js';

 export enum PackageManagers {
  Pip = 'pip',
@@ -6,9 +6,9 @@ import utils from 'util';
 import * as path from 'path';
 import os from 'os';

-import CacheDistributor from './cache-distributor';
-import {IS_WINDOWS} from '../utils';
-import {CACHE_DEPENDENCY_BACKUP_PATH} from './constants';
+import CacheDistributor from './cache-distributor.js';
+import {IS_WINDOWS} from '../utils.js';
+import {CACHE_DEPENDENCY_BACKUP_PATH} from './constants.js';

 class PipCache extends CacheDistributor {
  private cacheDependencyBackupPath: string = CACHE_DEPENDENCY_BACKUP_PATH;
@@ -3,7 +3,7 @@ import * as os from 'os';
 import * as path from 'path';
 import * as core from '@actions/core';

-import CacheDistributor from './cache-distributor';
+import CacheDistributor from './cache-distributor.js';

 class PipenvCache extends CacheDistributor {
  constructor(
@@ -4,8 +4,8 @@ import * as path from 'path';
 import * as exec from '@actions/exec';
 import * as core from '@actions/core';

-import CacheDistributor from './cache-distributor';
-import {logWarning} from '../utils';
+import CacheDistributor from './cache-distributor.js';
+import {logWarning} from '../utils.js';

 class PoetryCache extends CacheDistributor {
  constructor(
@@ -2,7 +2,7 @@ import * as core from '@actions/core';
 import * as cache from '@actions/cache';

 import fs from 'fs';
-import {State} from './cache-distributions/cache-distributor';
+import {State} from './cache-distributions/cache-distributor.js';

 // Added early exit to resolve issue with slow post action step:
 // - https://github.com/actions/setup-node/issues/878
@@ -1,6 +1,6 @@
 import * as path from 'path';
-import * as graalpyInstall from './install-graalpy';
-import {IS_WINDOWS, validateVersion, IGraalPyManifestRelease} from './utils';
+import * as graalpyInstall from './install-graalpy.js';
+import {IS_WINDOWS, validateVersion, IGraalPyManifestRelease} from './utils.js';

 import * as semver from 'semver';
 import * as core from '@actions/core';
@@ -1,5 +1,5 @@
 import * as path from 'path';
-import * as pypyInstall from './install-pypy';
+import * as pypyInstall from './install-pypy.js';
 import {
  IS_WINDOWS,
  WINDOWS_ARCHS,
@@ -9,7 +9,7 @@ import {
  validatePythonVersionFormatForPyPy,
  IPyPyManifestRelease,
  getBinaryDirectory
-} from './utils';
+} from './utils.js';

 import * as semver from 'semver';
 import * as core from '@actions/core';
@@ -1,10 +1,10 @@
 import * as os from 'os';
 import * as path from 'path';
-import {IS_WINDOWS, IS_LINUX, getOSInfo} from './utils';
+import {IS_WINDOWS, IS_LINUX, getOSInfo} from './utils.js';

 import * as semver from 'semver';

-import * as installer from './install-python';
+import * as installer from './install-python.js';

 import * as core from '@actions/core';
 import * as tc from '@actions/tool-cache';
@@ -16,7 +16,7 @@ import {
  createSymlinkInFolder,
  isNightlyKeyword,
  getNextPageUrl
-} from './utils';
+} from './utils.js';

 const TOKEN = core.getInput('token');
 const AUTH = !TOKEN ? undefined : `token ${TOKEN}`;
@@ -17,7 +17,7 @@ import {
  writeExactPyPyVersionFile,
  getBinaryDirectory,
  getDownloadFileName
-} from './utils';
+} from './utils.js';

 export async function installPyPy(
  pypyVersion: string,
@@ -2,11 +2,11 @@ import * as path from 'path';
 import * as core from '@actions/core';
 import * as tc from '@actions/tool-cache';
 import * as exec from '@actions/exec';
+import {ExecOptions} from '@actions/exec';
 import * as httpm from '@actions/http-client';
 import * as fs from 'fs';
 import * as semver from 'semver';
-import {ExecOptions} from '@actions/exec/lib/interfaces';
-import {IS_WINDOWS, IS_LINUX, getDownloadFileName} from './utils';
+import {IS_WINDOWS, IS_LINUX, getDownloadFileName} from './utils.js';
 import {IToolRelease} from '@actions/tool-cache';

 const TOKEN = core.getInput('token');
@@ -222,7 +222,8 @@ export async function getManifest(): Promise<tc.IToolRelease[]> {
    const message = err instanceof Error ? err.message : String(err);
    // Fail loudly so the action doesn't exit 0 without installing Python.
    throw new Error(
-      `Failed to fetch the Python versions manifest. The response was empty, truncated, or invalid, and all retries were exhausted. ${message}`
+      `Failed to fetch the Python versions manifest. The response was empty, truncated, or invalid, and all retries were exhausted. ${message}`,
+      {cause: err}
    );
  }
 }
@@ -1,18 +1,19 @@
 import * as core from '@actions/core';
-import * as finder from './find-python';
-import * as finderPyPy from './find-pypy';
-import * as finderGraalPy from './find-graalpy';
+import * as finder from './find-python.js';
+import * as finderPyPy from './find-pypy.js';
+import * as finderGraalPy from './find-graalpy.js';
 import * as path from 'path';
 import * as os from 'os';
+import {fileURLToPath} from 'url';
 import fs from 'fs';
-import {getCacheDistributor} from './cache-distributions/cache-factory';
+import {getCacheDistributor} from './cache-distributions/cache-factory.js';
 import {
  isCacheFeatureAvailable,
  logWarning,
  IS_MAC,
  getVersionInputFromFile,
  getVersionsInputFromPlainFile
-} from './utils';
+} from './utils.js';
 import {exec} from '@actions/exec';

 function isPyPyVersion(versionSpec: string) {
@@ -29,7 +30,7 @@ async function installPipPackages(pipInstall: string) {
    const installArgs = pipInstall.trim().split(/\s+/);
    await exec('python', ['-m', 'pip', 'install', ...installArgs]);
    core.info('Successfully installed pip packages');
-  } catch (error) {
+  } catch {
    core.setFailed(
      `Failed to install pip packages from "${pipInstall}". Please verify that the package names, versions, or requirements files provided are correct and installable, that the specified packages and versions can be resolved from PyPI or the configured package index, and that your network connection is stable and allows access to the package index.`
    );
@@ -168,7 +169,11 @@ async function run() {
        'The `python-version` input is not set.  The version of Python currently in `PATH` will be used.'
      );
    }
-    const matchersPath = path.join(__dirname, '../..', '.github');
+    const matchersPath = path.join(
+      path.dirname(fileURLToPath(import.meta.url)),
+      '../..',
+      '.github'
+    );
    core.info(`##[add-matcher]${path.join(matchersPath, 'python.json')}`);
  } catch (err) {
    core.setFailed((err as Error).message);
@@ -258,7 +258,7 @@ export function getVersionInputFromTomlFile(versionFile: string): string[] {
  pyprojectFile = pyprojectFile.replace(/\r\n/g, '\n');

  const pyprojectConfig = toml.parse(pyprojectFile);
-  let keys = [];
+  let keys: string[] = [];

  if ('project' in pyprojectConfig) {
    // standard project metadata (PEP 621)
@@ -267,7 +267,7 @@ export function getVersionInputFromTomlFile(versionFile: string): string[] {
    // python poetry
    keys = ['tool', 'poetry', 'dependencies', 'python'];
  }
-  const versions = [];
+  const versions: string[] = [];
  const version = extractValue(pyprojectConfig, keys);
  if (version !== undefined) {
    versions.push(version);
@@ -376,7 +376,7 @@ export function getVersionInputFromPipfileFile(versionFile: string): string[] {
  } else {
    keys.push('python_version');
  }
-  const versions = [];
+  const versions: string[] = [];
  const version = extractValue(pipfileConfig, keys);
  if (version !== undefined) {
    versions.push(version);
@@ -3,7 +3,7 @@
    /* Basic Options */
    // "incremental": true,                   /* Enable incremental compilation */
    "target": "ES2022",                          /* Specify ECMAScript target version: 'ES3' (default), 'ES5', 'ES2015', 'ES2016', 'ES2017', 'ES2018', 'ES2019' or 'ESNEXT'. */
-    "module": "commonjs",                     /* Specify module code generation: 'none', 'commonjs', 'amd', 'system', 'umd', 'es2015', or 'ESNext'. */
+    "module": "NodeNext",                     /* Specify module code generation. */
    // "allowJs": true,                       /* Allow javascript files to be compiled. */
    // "checkJs": true,                       /* Report errors in .js files. */
    // "jsx": "preserve",                     /* Specify JSX code generation: 'preserve', 'react-native', or 'react'. */
@@ -60,5 +60,5 @@
    // "experimentalDecorators": true,        /* Enables experimental support for ES7 decorators. */
    // "emitDecoratorMetadata": true,         /* Enables experimental support for emitting type metadata for decorators. */
  },
-  "exclude": ["node_modules", "**/*.test.ts"]
+  "exclude": ["node_modules", "**/*.test.ts", "jest.config.ts"]
 }