React Native项目引入jail-monkey后Jest测试报错‘Cannot use import statement outside a module’的解决求助

I've run into this exact issue before with React Native modules that ship untranspiled ES6 code. Here's how I fixed it for jail-monkey:

Step 1: Update Jest's transformIgnorePatterns to include jail-monkey #

The error happens because Jest is ignoring jail-monkey in its transpilation process, leaving the ES module import statements unprocessed. Add jail-monkey to your transformIgnorePatterns whitelist so Babel can handle it:

In your jest.config.js:

transformIgnorePatterns: [
	'node_modules/(?!(react-native' +
		'|react-navigation-tabs' +
		'|react-native-splash-screen' +
		'|react-native-screens' +
		'|react-native-reanimated' +
		'|@react-native' +
		'|react-native-vector-icons' +
		'|react-native-webview' +
		'|jail-monkey' // Add this line
	')/)',
],

Step 2: Ensure your transform config covers all file types #

Your current transform only handles .jsx files, but jail-monkey uses .js files. Update the transform rule to include .js, and make sure TypeScript files are handled by ts-jest:

transform: {
	'^.+\\.(js|jsx)$': 'babel-jest',
	'^.+\\.(ts|tsx)$': 'ts-jest',
},

Step 3: Mock jail-monkey for Jest tests (optional but recommended) #

Since Jest runs in a Node environment and can't access React Native's native APIs, mocking jail-monkey will prevent further errors and make your tests more reliable. Add this to your jest.setup.js:

jest.mock('jail-monkey', () => ({
	// Mock the methods you use in your app
	isJailBroken: jest.fn(() => false),
	isRooted: jest.fn(() => false),
	// Add other methods like detectDebugger, etc., as needed
}));

Why this works: #

• By adding jail-monkey to transformIgnorePatterns, you tell Jest not to skip transpiling it, so Babel converts its ES module syntax to CommonJS which Jest can understand.
• Expanding the transform config ensures all relevant file types are processed correctly by Babel and ts-jest.
• Mocking the library lets you control its behavior in tests without relying on native code.

After making these changes, run your Jest tests again—the SyntaxError should be gone.

内容的提问来源于stack exchange，提问作者Onyx