[Miodec]

Summary

Split out of #8491 (Solid Words component) to shrink its diff. No behaviour change on master: the existing goTo / updatePosition path is the same code, moved into moveTo.

 Caret (elements/caret.ts)
-  goTo(options)
-    requestDebouncedAnimationFrame("caret.<id>.goTo", () => ...measure + animate...)
+  goTo(options: GoToOptions)
+    requestDebouncedAnimationFrame("caret.<id>.goTo", () => this.moveTo(options))
+  goToNow(options: GoToOptions)            // new, unused on master
+    cancelPendingAnimationFrame("caret.<id>.goTo")
+    this.moveTo(options)
+  private moveTo(options)                  // old goTo body, unchanged

 test/caret.ts
-  updatePosition(noAnim) -> caret.goTo({...})
+  positionOptions(noAnim)                  // shared options builder
+  updatePosition(noAnim) -> caret.goTo(positionOptions(noAnim))
+  updatePositionNow(noAnim) -> caret.goToNow(positionOptions(noAnim))   // new, unused on master

goToNow / updatePositionNow are used by #8491, where the caret moves inside the shared words frame right after the DOM update instead of queueing its own frame.

Evidence

• Browser (master renderer): caret starts at letter 0, after wa sits before letter 2, after extra letters + space + h sits before letter 1 of the next word.
• frontend/__tests__/test + __tests__/elements (258) pass.

Merge Danger

Door: two-way

Blast Radius: caret

Pure extraction; the moved body is unchanged (diff is mostly re-indentation).

🤖 Generated with Claude Code

[Copilot]

🟢 Approval recommended

The change is a faithful, behavior-preserving extraction with verified dependencies and matching frame-id handling, and the new immediate-move helpers are isolated and unused on master.

No open issues 🎉

What changed in this PR

This PR is a pure, behavior-preserving refactor of the test caret, split out of #8491 to shrink that PR's diff. It extracts the body of Caret.goTo into a new private moveTo method and introduces an immediate (non-debounced) path (goToNow / updatePositionNow) that #8491 will use to move the caret inside the shared words animation frame instead of queuing its own frame. On master these new functions are introduced but unused.

Changes:

• Extract goTo's rAF callback body into private moveTo(options); goTo now just schedules moveTo via requestDebouncedAnimationFrame.
• Add goToNow(options) which cancels any pending debounced frame (caret.<id>.goTo) and runs moveTo synchronously; hoist the inline options type into a reusable GoToOptions type.
• In test/caret.ts, factor shared option-building into positionOptions(noAnim) and add updatePositionNow wrapping goToNow.

File	Description
frontend/​src/​ts/​elements/​caret.ts	Extracts moveTo, adds goToNow, imports cancelPendingAnimationFrame, hoists GoToOptions type.
frontend/​src/​ts/​test/​caret.ts	Adds shared positionOptions builder and new updatePositionNow that calls goToNow.

I verified that cancelPendingAnimationFrame is exported (utils/debounced-animation-frame.ts:23) and uses the same frame id (caret.<id>.goTo) as requestDebouncedAnimationFrame, that the extracted moveTo body is logically identical to the prior goTo callback (only re-indentation/reformatting), and that Parameters<Caret["goTo"]>[0] resolves to the new GoToOptions type so positionOptions stays correctly typed. No issues found.

_{Review effort: Balanced}

[Miodec]

Folded into #8491: the caret moves synchronously there, so goToNow isn't needed.