show warning when using userevent.type and blur() #460
Description
@testing-library/user-eventversion: 12.1.5- Testing Framework and version: Jest 26.4.2
- DOM Environment: jsdom 16.4.0 through Jest
Relevant code or config
const MyTest = () => {
const ref = useRef();
const [a, setA] = useState('');
function onChange(e) {
setA(e.target.value);
if (e.target.value === 'a') {
ref.current.blur();
}
}
return (
<div>
<input ref={ref} value={a} onChange={onChange} data-testid="inputRef" />
</div>
);
};
it('test', () => {
const wrapper = render(<MyTest />);
userEvent.type(screen.getByTestId('inputRef'), 'a');
expect(1).toEqual(1);
});What you did:
run the test
What happened:
the console will show warning message as follows:
UnhandledPromiseRejectionWarning: TypeError: Cannot read property 'length' of undefined
(Use `node --trace-warnings ...` to show where the warning was created)
(node:1220) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). To terminate the node process on unhandled promise rejection, use the CLI flag `--unhandled-rejections=strict` (see https://nodejs.org/api/cli.html#cli_unhandled_rejections_mode). (rejection id: 3)
(node:1220) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.
and if I try catch the async call in typeImpl and expose the error, it show as follows:
TypeError: Cannot read property 'length' of undefined
at setSelectionRange (/someplace/node_modules/@testing-library/user-event/dist/type.js:243:70)
at fireInputEventIfNeeded (/someplace/node_modules/@testing-library/user-event/dist/type.js:272:5)
at typeCharacter (/someplace/node_modules/@testing-library/user-event/dist/type.js:326:26)
at callback (/someplace/node_modules/@testing-library/user-event/dist/type.js:219:26)
at /someplace/node_modules/@testing-library/user-event/dist/type.js:144:31
at typeImpl (/someplace/node_modules/@testing-library/user-event/dist/type.js:159:6)
at Object.type (/someplace/node_modules/@testing-library/user-event/dist/type.js:73:14)
at Object.<anonymous> (/someplace/src/client/components/common/date-picker/date-range-picker-input.test.js:248:15)
at Object.asyncJestTest (/someplace/node_modules/jest-jasmine2/build/jasmineAsyncInstall.js:106:37)
at /someplace/node_modules/jest-jasmine2/build/queueRunner.js:45:12
at new Promise (<anonymous>)
at mapper (/someplace/node_modules/jest-jasmine2/build/queueRunner.js:28:19)
at /someplace/node_modules/jest-jasmine2/build/queueRunner.js:75:41
at processTicksAndRejections (internal/process/task_queues.js:93:5)
at typeImpl (../node_modules/@testing-library/user-event/dist/type.js:161:13)
Problem description:
seems like currentElement is returning document.body element since input component lost its focus. and thus the value of this element is undefined.
Suggested solution:
Line 234 in 5feaa94
if (typeof value === 'undefined') {
return;
}