fix: Memory leak caused by caching event objects

[gaoyuan123]

The event object is not cleared after reporting, causing the dom to be cached

[Oscurz]

What type of info is leaking.

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On Fri, Jan 13, 2023, 1:46 AM gaoyuan123 ***@***.***> wrote: The event object is not cleared after reporting, causing the dom to be cached ------------------------------ You can view, comment on, or merge this pull request online at: #307 Commit Summary - ec86bba <ec86bba> fix: Memory leak caused by caching event objects File Changes (1 file <https://github.com/GoogleChrome/web-vitals/pull/307/files>) - *M* src/lib/polyfills/firstInputPolyfill.ts <https://github.com/GoogleChrome/web-vitals/pull/307/files#diff-a2d2026423041483bca4d5fe0543fec839b1741f63cf0b38a08f9e6959a6f7ba> (1) Patch Links: - https://github.com/GoogleChrome/web-vitals/pull/307.patch - https://github.com/GoogleChrome/web-vitals/pull/307.diff — Reply to this email directly, view it on GitHub <#307>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AWSXWJGSYOX3UBGGB2TKMSTWSEP6TANCNFSM6AAAAAAT2GTGZQ> . You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>

[gaoyuan123]

What type of info is leaking.
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On Fri, Jan 13, 2023, 1:46 AM gaoyuan123 @.> wrote: The event object is not cleared after reporting, causing the dom to be cached ------------------------------ You can view, comment on, or merge this pull request online at: #307 Commit Summary - ec86bba <ec86bba> fix: Memory leak caused by caching event objects File Changes (1 file https://github.com/GoogleChrome/web-vitals/pull/307/files) - M src/lib/polyfills/firstInputPolyfill.ts https://github.com/GoogleChrome/web-vitals/pull/307/files#diff-a2d2026423041483bca4d5fe0543fec839b1741f63cf0b38a08f9e6959a6f7ba (1) Patch Links: - https://github.com/GoogleChrome/web-vitals/pull/307.patch - https://github.com/GoogleChrome/web-vitals/pull/307.diff — Reply to this email directly, view it on GitHub <#307>, or unsubscribe https://github.com/notifications/unsubscribe-auth/AWSXWJGSYOX3UBGGB2TKMSTWSEP6TANCNFSM6AAAAAAT2GTGZQ . You are receiving this because you are subscribed to this thread.Message ID: @.>

You can look at the submission. In the firstInputPolyfill.ts file, there are two variables: firstInputEvent and callbacks cache the user's first interaction event and callback method respectively. In the reportFirstInputDelayIfRecordedAndValid method, the callbacks cache is cleared, but firstInputEvent is not cleaned up, The target in the event attribute points to dom.

[tunetheweb]

Closing this as we plan to deprecate the FID Polyfill in v4 as per #238