jest-mock-warn mock console.warn Installation yarn add -D jest-mock-warn Usage import { mockWarn } from 'jest-mock-warn' function myFunction() { if (!arguments.length) console.warn('provide an argument')} describe('my tests', () => { mockWarn() it('warns when called without arguments', () => { myFunction() expect('provide an argument').toHaveBeenWarned() expect('provide an argument').toHaveBeenWarnedTimes(1) expect('provide an argument').toHaveBeenLastWarned() })}) API toHaveBeenWarned() toHaveBeenWarnedLast() toHaveBeenWarnedTimes(n: number) License MIT