import log from 'loglevel'; import { isErrorWithMessage, logErrorWithMessage } from './error'; jest.mock('loglevel'); afterEach(() => { jest.resetAllMocks(); }); describe('error module', () => { describe('isErrorWithMessage', () => { it('returns true when passed an instance of an Error', () => { expect(isErrorWithMessage(new Error('test'))).toBe(true); }); it('returns false when passed a string', () => { expect(isErrorWithMessage('test')).toBe(false); }); }); describe('logErrorWithMessage', () => { it('calls loglevel.error with the error.message when passed an instance of Error', () => { logErrorWithMessage(new Error('test')); expect(log.error).toBeCalledWith('test'); }); it('calls loglevel.error with the parameter passed in when parameter is not an instance of Error', () => { logErrorWithMessage({ test: 'test' }); expect(log.error).toBeCalledWith({ test: 'test' }); }); }); });