fix useSyncExternalStore relying on changed render values
#3655
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Size Change: +74 B (0%) Total Size: 43.8 kB
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JoviDeCroock
commented
Aug 8, 2022
| let i = 0; | ||
| const getSnapshot = sinon.spy(() => { | ||
| return () => 'value: ' + i++; |
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getSnapshot must return a cached value. If getSnapshot is called multiple times in a row, it must return the same exact value unless there was a store update in between.
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fixes #3654
It looks like Apollo and other libs can have their snapshot changed during render time, i.e. not part of the subscribe, this means that we need to check in a layout effect whether we are due to re-render, luckily this is similar how React does it as well 😅