[EuiDataGrid] shows a warning in the test environment about eui HOT 4 CLOSED

I'm going to go ahead and close this as a wontfix as this isn't an issue with EUI itself but rather a third party dependency (jsdom), and a workaround exists (see above code snippet).

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@mbondyra I'm actually not able to reproduce this on either local EUI or in a CodeSandbox 😕

Are you seeing the error in https://codesandbox.io/p/sandbox/white-mountain-3pypwc?file=%2Fdemo.js

? I tested in both Firefox and Chrome and no NaN error appeared in the dev console.

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OH sorry - I missed the part where this affects tests 🙈 This is likely a jsdom issue (e.g., DOM elements not actually having heights etc) that will need to be worked around/polyfilled in a local Jest test setup.

I'll poke around a bit more to confirm what's needed to get this working, but it's possible this may not be something EUI will fix in production/source code.

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The missing jsdom property appears to be window.getComputedStyle and it only appears to occur on rerender - see jsdom/jsdom#2986 🥲

The NaN generated comes from these lines specifically:

I could add an IS_JEST_ENVIRONMENT check to our internal calculateHeightForLineCount logic, but that feels kinda bad when our dynamic line height logic/tests work right now in Jest without a workaround. Maybe we should wait for jsdom to fix the issue on their end? 😬

@mbondyra For your use case with a useEffect rerender, I think I lean towards asking y'all to polyfill window.getComputedStyle instead. Can you try something like:

  jest
    .spyOn(window, 'getComputedStyle')
    .mockImplementation(() => ({ lineHeight: '16px' } as any));

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