How to suppress application logging messages from a node.js application when running unit tests?

Question

While unit-testing my node.js application (which is basically a REST backend) using mocha and supertest, I need only the test-specific message on the screen, but the stdout

Answer 1

Here's a pretty simple solution that uses SinonJS's test stubs to suppress all console.log/info/warn/error statements before running your tests.

// my-method.js

export function myMethod() {
    console.log(`I'm about to return true`)
    return true
}

---

// my-method.test.js

import {describe, it, before} from 'mocha'
import chai from 'chai'
import sinon from 'sinon'
import chalk from 'chalk'
import {myMethod} from './my-method.js'

const expect = chai.expect

describe(chalk.underline('My Test Group'), () => {

    before(() => {
        sinon.stub(console, 'log')  // disable console.log
        sinon.stub(console, 'info')  // disable console.info
        sinon.stub(console, 'warn')  // disable console.warn
        sinon.stub(console, 'error')  // disable console.error
    })

    describe('myMethod', () => {
        it('should return true', () => {
            expect(myMethod()).to.be.true  // without printing to the console
        })
    })
})

---

// output

My Test Group
  myMethod
    ✓ should return true