use module exports

config/jest.config.js

@@ -10,6 +10,10 @@ const jestConfig = {
 	rootDir: "../src/",
 	testEnvironment: "node",
 	testRegex: "(/__tests__/.*|(\\.|/)test)\\.ts",
+	moduleNameMapper: {
+		"^@actions/core$": "<rootDir>/__mocks__/actions-core.js",
+		"^@actions/tool-cache$": "<rootDir>/__mocks__/actions-tool-cache.js",
+	},
 	transform: {
 		".ts": [
 			"ts-jest",
@@ -25,4 +29,4 @@ const jestConfig = {
 	verbose: true,
 };
 
-export default jestConfig;
+module.exports = jestConfig;

src/__mocks__/actions-core.js

@@ -0,0 +1,14 @@
+module.exports = {
+	getInput: jest.fn(() => ""),
+	getBooleanInput: jest.fn(() => false),
+	setOutput: jest.fn(),
+	setSecret: jest.fn(),
+	exportVariable: jest.fn(),
+	setFailed: jest.fn(),
+	info: jest.fn(),
+	warning: jest.fn(),
+	error: jest.fn(),
+	debug: jest.fn(),
+	addPath: jest.fn(),
+	isDebug: jest.fn(() => false),
+};

src/__mocks__/actions-tool-cache.js

@@ -0,0 +1,7 @@
+module.exports = {
+	downloadTool: jest.fn(),
+	extractTar: jest.fn(),
+	extractZip: jest.fn(),
+	cacheDir: jest.fn((dir) => Promise.resolve(dir)),
+	find: jest.fn(() => ""),
+};