Performance issue with the byRole query causing timeout errors

• @testing-library/jest-dom version: 5.11.0
• node version: 12.14.1
• yarn version: 1.21.1

What you did:

I converted several tests of the project I work on, which were using manual queries with container and querySelector, to use screen prioritizing the query byRole as recommended.

What happened:

There are some timeout errors when I run some tests after the conversion to use screen and the byRole selector.

Reproduction:

I made a small example to demonstrate the difference in ms in a small case, like a table with 8 cells, when using the query byRole compared to byText.

Problem description:

At the moment there is a certain performance problem with the byRole selector, which even causes a timeout problem in tests, something that does not happen with other selectors such as byText.

Below is the time it takes me to run a test on the project I work on when using the byRole query (in which there is a timeout error in some moments for taking too long).

Then, the time it takes to perform the same test, but using the byText selector. I have run the test several times this way and with this selector I did not give a timeout because it is fast.

Suggested solution:

I believe that for now the solution would be not to suggest the query byRole as a priority, at least until there are some more performance improvements to get closer to the other selectors.

I apologize because I did not get to look at the code in depth to try to understand a little if there is a way to bring about an improvement in byRole. I am also aware of the benefits that this selector brings and I am willing to waste more time to run the tests to use it, however the time difference is still large and causing timeout errors. Thank you!!!

[idanen]

I totally agree with @eps1lon , but if there is something to do to improve performance we should give it a try, shouldn’t we? The difference between getByRole and getByLabelText is pretty big (notice in the test I compared to 5 times the duration and it’s still longer than that), so I think we should at least make some effort to reduce it

[eps1lon]

If you’re confident that you can manually verify the checks ByRole provides then I suggest switching to other queries. ByRole considers the a11y tree, styles and the accname spec. These checks are expensive but have a higher confidence that what you’re testing is actually what a screen reader would “see”.

It’s like any other tool: If you don’t need the features then you should switch to a tool with smaller feature set. If test performance is a bigger issue for you than test confidence then ByRole is not the right tool.

One thing: A real-world repro would help us a lot improving performance. We’ve had success in the past with good repros since they help us identify bottlenecks. Screenshots of code don’t help us very much. Small examples that don’t reproduce the issue are also not helpful.