Prevent extra render item calls #253
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| @@ -101,4 +101,28 @@ describe("FlashList", () => { | |||
| flashList.instance.getUpdatedWindowCorrectionConfig().value.windowShift | |||
| ).toBe(-100); | |||
| }); | |||
| it("calls render item only when data of the items has changed", (done) => { | |||
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| // There's some async operation happening inside the scroll component causing jest to throw errors | ||
| // This is a workaround to silence it. | ||
| requestAnimationFrame(() => { |
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Does that happen due to the setProps call? I wonder if this is something users will run in, too - if so, we should either document it or try to solve in the mock we provide.
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I'm looking into it. Here I was thinking I'd just get this done in a few min and this issue popped up. This is happening because this is the last test to run and some import happen after jest has teared down.
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@fortmarek I checked this and everything on the surface looks fine. I'm not going to spend more time on this as we need to wrap up build phase. I have created an issue here to track it: #255
I'll come back to it. Till then this test is serving it's purpose well.
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yes, I don't mind it for our internal test suite but we should investigate to ensure users won't unnecessarily run into this (or as mentioned, at least document it once we understand the problem). I put it in the opensource milestone as it's important to look at it before we make it public.
Co-authored-by: Marek Fořt <marek.fort@shopify.com>
Description
If the render item has very complex JSX being returned directly this change can improve performance by multiple folds.
Checklist