fix(ui): a late form takes a dialog's focus once, even if it arrived elsewhere

The watch stayed armed when the form arrived while the focus was off the close button, so a
later change in the body pulled the focus off a close button the user went back to. It now
disarms on arrival and re-arms only when the focus is taken away.
This commit is contained in:
2026-10-04 04:16:52 +02:00
parent 7dbda60815
commit 4191189b4c
2 changed files with 34 additions and 5 deletions
@@ -116,6 +116,28 @@ describe("Modal initial focus by purpose (C4)", () => {
expect(document.activeElement).toBe(cancel);
});
// …and it stays the user's: the form disarms the watch when it arrives, so a later change in the
// body (a hint appearing as they type) cannot pull the focus off a ✕ they went back to.
it("field that loads late: once arrived, it never takes the focus off the ✕ again", async () => {
const view = (ready: boolean, hint = false) => (
<Modal initialFocus="field" title="t" onClose={() => {}}>
<Late ready={ready} />
{hint && <p>hint</p>}
<ModalFooter>
<button>cancel</button>
</ModalFooter>
</Modal>
);
const { rerender } = render(view(false));
act(() => screen.getByRole("button", { name: "cancel" }).focus());
rerender(view(true));
await act(async () => {});
act(() => closeBtn().focus());
rerender(view(true, true));
await act(async () => {});
expect(document.activeElement).toBe(closeBtn());
});
it("close: the ✕, even with a field in the body", () => {
render(
<Modal initialFocus="close" title="t" onClose={() => {}}>
+12 -5
View File
@@ -106,9 +106,12 @@ export default function Modal({
// A form that loads after the dialog opens (the issue composer shows a spinner first) has no field
// to take the focus at open, so it lands on the ✕. When the first control arrives the focus moves
// there — but only while it still rests on the ✕: a user who has moved it keeps it where it is.
// The watch re-arms when the focused control is taken away (a failed load's Retry giving way to
// the spinner again): the focus fell to <body>, so it waits on the ✕ for the form (E32 review).
// Only <body>: focus in a dialog stacked on top is not this one's to take.
// The form takes it ONCE: arrived while the focus was elsewhere, it disarms all the same, or a later
// mutation would pull the focus off a ✕ the user went back to (E32 review round 2). The watch
// re-arms only when the focus is taken away, not moved: the body has no control again, or the
// focused one went (a failed load's Retry giving way to the spinner, or straight to the form) and
// the focus fell to <body> — it then waits on the ✕ for the form (E32 review). Only <body>: focus
// in a dialog stacked on top is not this one's to take.
useEffect(() => {
const body = bodyRef.current;
if (initialFocus !== "field" || !body || focusablesIn(body).length > 0) return;
@@ -119,9 +122,13 @@ export default function Modal({
armed = true;
}
const first = focusablesIn(body)[0];
if (!armed || !first || document.activeElement !== closeRef.current) return;
if (!first) {
armed = true;
return;
}
if (!armed) return;
armed = false;
first.focus();
if (document.activeElement === closeRef.current) first.focus();
});
watch.observe(body, { childList: true, subtree: true });
return () => watch.disconnect();