Simulate keydown on document for JEST unit testing

unit-testing reactjs addeventlistener jestjs reactjs-testutils
Vaibhav Garg picture Vaibhav Garg · Nov 10, 2015 · Viewed 16.1k times · Source

Using JEST to unit test a component that has a keydown listener attached to the document.

How can I test this in JEST? How do I simulate the keydown event on the document? I need the event listener to be on the document since it is supposed to respond the keyboard action irrespective of the focussed element.

EDIT: The question here is about simulating the event on the document or the document.body. All the examples are regarding an actual DOM node, that works fine but the document does not.

Currently trying to do this:

TestUtils.Simulate.keyDown(document, {keyCode : 37}); // handler not invoked

Answer

Iris Schaffer picture Iris Schaffer · Jan 24, 2016

I had the exact same problem and unfortunately couldn't find any details on how to solve this using TestUtils.Simulate. However this issue gave me the idea of simply calling .dispatchEvent with a KeyboardEvent inside my jest tests directly:

var event = new KeyboardEvent('keydown', {'keyCode': 37});
document.dispatchEvent(event);

You can find details on the KeyboardEvent here: https://developer.mozilla.org/en-US/docs/Web/API/KeyboardEvent/KeyboardEvent

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