chore: add file extensions in tests

Author: dsanders11

__tests__/index.test.ts

@@ -3,7 +3,7 @@
  */
 import { describe, expect, it, vi } from 'vitest';
 
-import * as main from '../src/main';
+import * as main from '../src/main.js';
 
 // Mock the action's entrypoint
 const runMock = vi.spyOn(main, 'run').mockImplementation(async () => {});

__tests__/lib.test.ts

@@ -3,7 +3,7 @@ import { beforeEach, describe, expect, it, vi } from 'vitest';
 import * as core from '@actions/core';
 import * as exec from '@actions/exec';
 
-import * as lib from '../src/lib';
+import * as lib from '../src/lib.js';
 
 vi.mock('@actions/core');
 vi.mock('@actions/exec');

__tests__/main.test.ts

@@ -5,9 +5,9 @@ import * as fs from 'node:fs';
 import * as core from '@actions/core';
 import { RequestError } from '@octokit/request-error';
 
-import * as lib from '../src/lib';
-import * as main from '../src/main';
-import { mockGetBooleanInput, mockGetInput } from './utils';
+import * as lib from '../src/lib.js';
+import * as main from '../src/main.js';
+import { mockGetBooleanInput, mockGetInput } from './utils.js';
 
 const createCommit = vi.fn();
 const createRef = vi.fn();