Simplify Jest-specific tests #11243
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Simplify Jest-specific tests #11243
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They were added after facebook#2576, but were only important when React.createElement was introduced as a migration path. Now that elements are used consistently, these tests shouldn't be necessary. I created a separate test specifically for scryRenderedComponentsWithType() though because that was the only one.
Today, the only remaining special behavior for Jest mocks is we let them render undefined. We don't plan to introduce any other special behavior for them in the future. (In fact, we already decided against replicating this special behavior for functional components.) Therefore, we can remove dependency on Jest automocking mechanism in these tests completely, and just explicitly mock the render method which is the only one for which we have special behavior. For clarity, we add an explicit test for mockComponent() API (whose naming is a bit of a lie).
trueadm
approved these changes
Oct 17, 2017
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It was a bit hard to say what's being tested there.
This was relevant in the past but today the only special case we have for Jest is here:
react/src/renderers/shared/fiber/ReactChildFiber.js
Lines 1450 to 1452 in 49d4381
and here:
react/src/renderers/shared/server/ReactPartialRenderer.js
Lines 412 to 415 in 49d4381
So I just test those specifically instead now.
The automock system is also legacy, and has been disabled by default on www this year. The other things these tests were testing are related to Jest mocking itself but it doesn’t make sense for me that we should test Jest. Especially since we don’t necessarily use the same version as www. If Jest breaks any of this behavior, they will notice it during their www sync so it shouldn’t be on our plate.
See individual commits for details.