with event

  • <ReactElement> with event <string> <assertion?>
  • <ReactElement> with event <string> <object> <assertion?>

with event .... [on]

with event can trigger events in both the shallow and full renderer. For the normal full renderer, TestUtils.Simulate is used to simulate the event. For the shallow renderer, it is expected that there is a prop with the name on[EventName], where the first letter of the event is capitalised.

e.g. with a button that counts it's own clicks

var renderer = createRenderer()
renderer.render(<MyButton />);
expect(renderer, 'with event', 'click', 'to have rendered', <button>Button was clicked 1 times</button>);

This works with the component directly, as a shallow renderer is automatically created. Also note that due to unexpected's clever string handling, you can concatenated the with event and the event name.

expect(<MyButton />, 'with event click', 'to have rendered', <button>Button was clicked 1 times</button>);

Given the following todo list:

var renderer = createRenderer()
    <TodoItem id={1} label="Buy flowers for the wife"/>
    <TodoItem id={2} label="Mow the lawn"/>
    <TodoItem id={3} label="Buy groceries"/>

If you want to trigger an event on a specific component, (i.e. not the top level component), use on after the event.

  'with event click',
  'on', <TodoItem id={3} />,
  'to contain', <TodoItem id={3} clicked={true} />

To pass arguments to the event, simply include the event object after the event name

  'with event mouseDown', { mouseX: 150, mouseY: 50 },
  'on', <TodoItem id={2} />,
  'to contain', <TodoItem id={2} clicked={false} />

This will call the function passed in the onMouseDown prop of the <TodoItem>.

You can take the renderer after the event has been triggered by using the promise returned from expect. This is often used to test that spy or mock callbacks have been called (using for instance sinon.js).

return expect(
  'with event click', 'on', <TodoItem id={2} />
).then(renderer => {
  const todoListInstance = renderer.getMountedInstance();
  expect(todoListInstance.state, 'to satisfy', { clicked: { 2: true } });


You can add an eventTarget prop to the expected to trigger the event on a child component. e.g.

var renderer = createRenderer()
renderer.render(<App />);
    'with event', 'click', 'on', <div className="click-test"><button eventTarget /></div>, 
    'to have rendered', 
        <div className="other-button"><button>Not clicked</button></div>
        <div className="click-test"><button>Button was clicked</button></div>