Multi tool use

test timers in react, sinon or jest

I have a funtion checkIdleTime, being set to be called periodically.

checkIdleTime

componentDidMount() {
var idleCheck = setInterval(this.checkIdleTime.bind(this), authTimeoutSeconds * 1000);
this.setState({idleCheck: idleCheck});

document.onkeypress = this.setActive;
}


I want to use the fake timer for test, but can't figure out how, tried sinon
and jest.

sinon

jest

beforeEach(() => {
checkIdleTime = jest.spyOn(PureMain.prototype, 'checkIdleTime');
wrapper = shallow(
<PureMain/>
);

jest.useFakeTimers();
//clock = sinon.useFakeTimers();
});

it('should check the idle time after [authTimeoutSeconds] seconds of inactivity', () => {

wrapper.instance().componentDidMount();

var idleCheck_timeout = wrapper.instance().state.idleCheck;
expect(idleCheck_timeout).not.toEqual(null);
expect(idleCheck_timeout._idleTimeout).toBe(authTimeoutSeconds * 1000);
jest.runAllTimers();
//clock.tick(authTimeoutSeconds * 1000 * 2);
expect(setInterval).toHaveBeenCalledTimes(1);//not work
expect(checkIdleTime).toHaveBeenCalledTimes(1);//not work
})


Got error:

Expected mock function to have been called one time, but it was called zero times.

I tried to follow those examples

https://facebook.github.io/jest/docs/en/timer-mocks.html

http://sinonjs.org/releases/v1.17.7/fake-timers/

Can't find a good example on how to spy on setInterval

setInterval

expect(setInterval.mock.calls.length).toBe(1)


Cannot read property 'calls' of undefined

expect(setInterval).toHaveBeenCalledTimes(1)


value must be a mock function or spy.

sinon

sinon

expect(setInterval).toHaveBeenCalledTimes(1)

expect(checkIdleTime).toHaveBeenCalledTimes(1)

1 Answer
1

Turned out the spy should be declared as:

setTimeout_spy = jest.spyOn(window, 'setTimeout');


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