paullewisn/jest-console-mock

jest-console-mock

Simple wrapper to mock (and unmock) console.log, .warn, .error calls

What this does

When testing, I wanted a way of hiding logs which I was expecting, while allowing those which I wasn't expecting to still show.

This code mocks the requested console, when it is called the message is checked against the list of expected messages, if none match it calls console.info with the message.

Usage

mockConsole(['messages'], 'log'|'warn'|'error')

index.js

  console.log('message1'); //expected
  console.log('message2'); //expected
  console.log('message3'); //unexpected

spec.js

beforeAll(() => {
  mockConsole(['message1', 'message2'], 'log');
});

it('should do something', () => {
  ****
});

output

should do something:
  console.info **/index.js:*
      message3

unmockConsole('log'|'warn'|'error')

index.js

  console.error('message1'); //expected
  console.error('message2'); //expected
  console.error('message3'); //unexpected

spec.js

beforeAll(() => {
  mockConsole(['message1', 'message2'], 'error');
});

afterEach(() => {
  unmockConsole('error');
});

it('should do something', () => {
  ****
});
it('should do something else', () => {
  ****
});

output

should do something:
  console.info **/index.js:*
      message3
      
should do something else:
  console.error **/index.js:*
      message1
  console.error **/index.js:*
      message2
  console.error **/index.js:*
      message3

unmockAllConsoles()

index.js

  console.log('message1'); //expected
  console.warn('message2'); //expected
  console.error('message3'); //expected

spec.js

beforeAll(() => {
  mockConsole(['message1'], 'log');
  mockConsole(['message2'], 'warn');
  mockConsole(['message3'], 'error');
});

afterEach(() => {
  unmockAllConsoles();
});

it('should do something', () => {
  ****
});
it('should do something else', () => {
  ****
});

output

should do something:
      
should do something else:
  console.log **/index.js:*
      message1
  console.warn **/index.js:*
      message2
  console.error **/index.js:*
      message3