[Solved] Which syntax correctly mocks a service call in a JavaScript unit test using Jest? — Ans: jest.mock('serviceModule', () => ({ fetchData: jest.fn() })); | Microservices

Microservices - Testing Microservices

Which syntax correctly mocks a service call in a JavaScript unit test using Jest?

Ajest.mock('serviceModule', () => ({ fetchData: jest.fn() }));

Bmock('serviceModule').fetchData = jest.fn();

Cjest.spyOn('serviceModule', 'fetchData');

DserviceModule.mockFetchData = jest.fn();

Step-by-Step Solution

Solution:

Step 1: Review Jest mocking syntax
Jest uses jest.mock(moduleName, factory) to mock modules.
Step 2: Identify correct syntax for mocking fetchData
jest.mock('serviceModule', () => ({ fetchData: jest.fn() })); correctly mocks 'serviceModule' with fetchData as a jest.fn().
Final Answer:
jest.mock('serviceModule', () => ({ fetchData: jest.fn() })); -> Option A
Quick Check:
Jest mock syntax = jest.mock(module, factory) [OK]

Quick Trick: Use jest.mock with factory function to mock modules [OK]

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Which syntax correctly mocks a service call in a JavaScript unit test using Jest?