Mockery Madness - Exploring the art of mocking a function post-testing a route

Question

Mockery Madness - Exploring the art of mocking a function post-testing a route

Before mocking the process function within the GatewayImpl class to return the 'mockData' payload, I need to ensure that all routes are tested.

import payload from './payloads/payloadRequire';        // payload for request
import {GatewayImpl} from '../src/classes/GatewayImpl'; //class containing the function
import mockData from './mockData/mockData';            // payload for response

var gatewayInstance = new GatewayImpl;
request.post('/route/test').send(payload) // testing route with specified payload

//const procc = fClass.proccess -> calling process function within GatewayImpl class
const spy = jest
.spyOn(GatewayImpl, 'procc') // spying on the process function
.mockReturnValue(mockData); // setting mock data to be returned when process is called

typescript mocking jestjs

Answer 1

Answer №1

Place the __mocks__ directory inside the src/classes folder.
Add GatewayImpl.js file to the __mocks__ directory.
Within the __mocks__/GatewayImpl.js file:

// Define mock implementation for GatewayImpl.
exports.GatewayImpl = {
  procc: jest.fn()
}

In your test file, include the line
```
jest.mock('../src/classes/GatewayImpl')
```
at the beginning.

jest.mock('../src/classes/GatewayImpl')
import payload from './payloads/payloadRequire';        // Payload to be sent
import {GatewayImpl} from '../src/classes/GatewayImpl'; // Class where the function resides
import mockData from './mockData/mockData';            // Mock response data

Inside either beforeAll or beforeEach, use
```
GatewayImpl.procc.mockReturnValue(mockData)
```
to set up the mocked return value.

describe('procc', () => {
  beforeAll(() => {
    GatewayImpl.procc.mockReturnValue(mockData);
  });
  it('returns the expected data', () => {
    request.post('/route/test').send(payload);
    expect(GatewayImpl.procc()).toBe(mockData);
  });
});

Answer 2

Place the __mocks__ directory inside the src/classes folder.
Add GatewayImpl.js file to the __mocks__ directory.
Within the __mocks__/GatewayImpl.js file:

// Define mock implementation for GatewayImpl.
exports.GatewayImpl = {
  procc: jest.fn()
}

In your test file, include the line
```
jest.mock('../src/classes/GatewayImpl')
```
at the beginning.

jest.mock('../src/classes/GatewayImpl')
import payload from './payloads/payloadRequire';        // Payload to be sent
import {GatewayImpl} from '../src/classes/GatewayImpl'; // Class where the function resides
import mockData from './mockData/mockData';            // Mock response data

Inside either beforeAll or beforeEach, use
```
GatewayImpl.procc.mockReturnValue(mockData)
```
to set up the mocked return value.

describe('procc', () => {
  beforeAll(() => {
    GatewayImpl.procc.mockReturnValue(mockData);
  });
  it('returns the expected data', () => {
    request.post('/route/test').send(payload);
    expect(GatewayImpl.procc()).toBe(mockData);
  });
});

Mockery Madness - Exploring the art of mocking a function post-testing a route

Answer №1

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