fix(shared): match add/removeEventListener options in onScroll cleanup (#2384)

[ErfanBagheri404]

Summary

useScroll (via onScroll in @react-spring/shared) leaks event listeners on cleanup.

addEventListener was called with { passive: true }:

window.addEventListener('resize', listener, { passive: true })
target.addEventListener('scroll', listener, { passive: true })

but removeEventListener was called without any options:

getTarget(container).removeEventListener('scroll', listener)
window.removeEventListener('resize', listener)

Per the DOM spec on matching event listeners, the capture flag must match between add and remove for the listener to be removed. While { passive: true } happens to default capture to false, strict environments that track the options object verbatim fail to match, leaving the listener attached — useScroll leaks a scroll + resize listener per component mount/unmount.

Changes

• packages/shared/src/dom-events/scroll/index.ts: extract a shared passiveOptions object used by both addEventListener and removeEventListener calls (scroll + resize + per-container onResize path), so the options always match.
• packages/shared/src/dom-events/scroll/onScroll.test.ts: regression test asserting removeEventListener is invoked with options equal to those passed to addEventListener.

Test plan

• npx vitest run packages/shared/src/dom-events/scroll/onScroll.test.ts — passes (mock throws on unmatched remove, none thrown)

Fixes #2384

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[joshuaellis]

you've got your two other PR commits in this. I think realistically you wanted to stack these PRs but to be honest, they should be made in isolation with each PR a single commit aimed at next. Please review all your PRs and amend accordingly before they can be reviewed.

[ErfanBagheri404]

Rebased and isolated all 5 PRs onto next — each branch now carries only its own single commit (no stacked siblings):

• fix(core): propagate immediate flag to to-array chain steps #2557 immediate-to-array-chain
• fix(animated): use WeakMap cache in createHost #2558 createhost-weakmap-cache
• fix(core): prevent infinite loop when skipAnimation + loop (#2409) #2559 skip-animation-loop-crash
• fix(shared): match add/removeEventListener options in onScroll cleanup (#2384) #2560 onscroll-listener-cleanup
• fix(shared): parse negative decimals without integer part in numberRegex (#2397) #2561 number-regex-negative-decimals

Force-pushed. Each is now a single isolated commit against next.

[joshuaellis]

Source fix in index.ts is correct — sharing one passiveOptions object makes add/remove match, leak gone.

Two blockers:

Test fails here. Tests run in Vitest browser mode (real Chromium), so the mock container hits the real ResizeObserver.observe() and throws before cleanup:

TypeError: Failed to execute 'observe' on 'ResizeObserver': parameter 1 is not of type 'Element'.

See resizeElement.test.ts in the same folder for the pattern — real document.createElement('div'). A real element also exposes a bad assertion: only scroll is added to the container (resize goes on window), so toHaveBeenCalledTimes(2) won't hold.

Formatting. oxfmt --check fails on both files (cleanup block in index.ts is mis-indented). Run the formatter.