This post goes over how to mock Amplitude Browser SDK with Jest.

Problem

I installed Amplitude Analytics SDK in my frontend project:

npm install @amplitude/analytics-browser

But when I ran my Jest tests, I got the error:

TypeError: (0 , analytics_core_1.UUID) is not a function

  at ./node_modules/@amplitude/analytics-browser/src/config.ts:283:9

Solution

I created a mock file amplitude-analytics-browser-mock.js:

mkdir -p __mocks__ && touch __mocks__/amplitude-analytics-browser-mock.js

With the code:

// __mocks__/amplitude-analytics-browser-mock.js
module.exports = {
  init: jest.fn(),
  track: jest.fn(),
  identify: jest.fn(),
  Identify: jest.fn(),
};

I updated my Jest config’s moduleNameMapper:

/** @type {import('jest').Config} */
const config = {
  moduleNameMapper: {
    '^@amplitude/analytics-browser$':
      '<rootDir>/__mocks__/amplitude-analytics-browser-mock.js',
  },
};

module.exports = config;

Then my tests passed!