Jest mock not being called / not returning expected value

Common Causes

1. 1Mock is defined after the import (hoisting issue)
2. 2Module uses named exports but mock replaces default export
3. 3Mock return value not configured (.mockReturnValue)
4. 4Component imports the module before the mock is set up
5. 5Using jest.mock with ES modules requires special handling

How to Fix

// Jest automatically hoists jest.mock() calls to the top
jest.mock('./api', () => ({
  fetchUsers: jest.fn().mockResolvedValue([{ id: 1 }]),
}));

import { fetchUsers } from './api'; // Mock is already in place

afterEach(() => {
  jest.clearAllMocks();
});

// Or globally in jest.config.ts:
export default {
  clearMocks: true,
};

Related Errors