fix(trigger): avoid flushSync for synchronous-call dedup

src/index.tsx

@@ -41,7 +41,6 @@ export type {
 
 import UniqueProvider, { type UniqueProviderProps } from './UniqueProvider';
 import { useControlledState } from '@rc-component/util';
-import { flushSync } from 'react-dom';
 
 export { UniqueProvider };
 export type { UniqueProviderProps };
@@ -386,14 +385,53 @@ export function generateTrigger(
     const openRef = React.useRef(mergedOpen);
     openRef.current = mergedOpen;
 
+    // Same-batch dispatch dedup for `internalTriggerOpen`.
+    //
+    // Multiple events routed through the same interaction batch —
+    // `pointerenter` + `focus` on open, `pointerleave` + `blur` on close —
+    // both call `internalTriggerOpen(sameValue)`. React state updates are
+    // async within a batch, so a state-based comparison would let the
+    // second call through. The ref catches it because it is written
+    // synchronously inside the handler.
+    //
+    // The ref is deliberately **never written from render body or from a
+    // layout effect**. Both would defeat the correctness properties the
+    // #622 review needed:
+    //
+    //   • A render-body sync leaks the baseline of a discarded concurrent
+    //     render (Suspense / transitions): the speculative `rawOpen`
+    //     write survives even though the render never commits, so a
+    //     later opposite dispatch on the still-committed target is
+    //     mistaken for a duplicate.
+    //   • A `useLayoutEffect([rawOpen])` sync loses to descendant layout
+    //     effects. React runs descendants' layout effects before their
+    //     parent's, so a target's `useLayoutEffect([open], () =>
+    //     target.blur())` can reach `internalTriggerOpen` while the
+    //     baseline still holds the previous value and the dispatch is
+    //     dropped as a duplicate.
+    //
+    // Instead the baseline is reset in a passive effect. `useEffect` runs
+    // only for actually-committed renders (discarded/suspended renders
+    // never reach it) and it runs after every layout effect has flushed,
+    // so it never races them. Between commits the ref carries the last
+    // dispatched value, which is exactly what same-batch dedup needs.
+    //
+    // See https://github.com/ant-design/ant-design/issues/57789 and the
+    // review threads on https://github.com/react-component/trigger/pull/622.
+    const lastDispatchRef = React.useRef<boolean | undefined>(undefined);
+
+    React.useEffect(() => {
+      lastDispatchRef.current = undefined;
+    });
+
     const internalTriggerOpen = useEvent((nextOpen: boolean) => {
-      flushSync(() => {
-        if (rawOpen !== nextOpen) {
-          setInternalOpen(nextOpen);
-          onOpenChange?.(nextOpen);
-          onPopupVisibleChange?.(nextOpen);
-        }
-      });
+      if (lastDispatchRef.current === nextOpen) {
+        return;
+      }
+      lastDispatchRef.current = nextOpen;
+      setInternalOpen(nextOpen);
+      onOpenChange?.(nextOpen);
+      onPopupVisibleChange?.(nextOpen);
     });
 
     // Trigger for delay

tests/concurrent-render.test.tsx

@@ -0,0 +1,168 @@
+/**
+ * Regression coverage for the concurrent-render blocker flagged in the second
+ * review round of #622 by @nrps9909.
+ *
+ * The specific scenario:
+ *
+ *   1. A controlled Trigger is committed with `popupVisible={false}`.
+ *   2. A `startTransition` attempts to move to `popupVisible={true}`, but a
+ *      child of the Trigger suspends. React holds the previously committed
+ *      UI while the transition is pending — the original target stays in
+ *      the DOM and remains the one wired to Trigger's `onFocus`/`onBlur`.
+ *   3. Focusing that still-committed original target should emit
+ *      `onOpenChange(true)` exactly once.
+ *
+ * A previous revision of the fix synchronized the dedup baseline in the
+ * render body:
+ *
+ *   if (lastDispatchedOpenRef.current !== rawOpen) {
+ *     lastDispatchedOpenRef.current = rawOpen;
+ *   }
+ *
+ * That write happens even in the *speculative* render for the suspended
+ * transition, and React does not roll back ref writes when a render is
+ * discarded. The ref then holds `true` (from the speculative rawOpen),
+ * so when the user focuses the still-committed target the dedup check
+ * treats the dispatch as a duplicate and drops it — 0 callbacks instead
+ * of 1.
+ *
+ * The current revision moves the ref reset into `React.useEffect` and
+ * never writes the ref during render. `useEffect` runs only for
+ * committed renders, so a discarded suspended transition cannot pollute
+ * the baseline. This test asserts the one-callback behaviour and fails
+ * against a render-body-sync revision (0 callbacks).
+ */
+import { act, cleanup, fireEvent, render } from '@testing-library/react';
+import { spyElementPrototypes } from '@rc-component/util/lib/test/domHook';
+import * as React from 'react';
+import Trigger from '../src';
+
+const flush = async () => {
+  for (let i = 0; i < 10; i += 1) {
+    act(() => {
+      jest.runAllTimers();
+    });
+    await act(async () => {
+      await Promise.resolve();
+    });
+  }
+};
+
+describe('Trigger.ConcurrentRender (#622 review)', () => {
+  let eleRect = { width: 100, height: 100 };
+  let spanRect = { x: 0, y: 0, left: 0, top: 0, width: 1, height: 1 };
+  let popupRect = { x: 0, y: 0, left: 0, top: 0, width: 100, height: 100 };
+
+  beforeAll(() => {
+    spyElementPrototypes(HTMLElement, {
+      clientWidth: { get: () => eleRect.width },
+      clientHeight: { get: () => eleRect.height },
+      offsetWidth: { get: () => eleRect.width },
+      offsetHeight: { get: () => eleRect.height },
+      offsetParent: { get: () => document.body },
+    });
+    spyElementPrototypes(HTMLDivElement, {
+      getBoundingClientRect() {
+        return popupRect;
+      },
+    });
+    spyElementPrototypes(HTMLSpanElement, {
+      getBoundingClientRect() {
+        return spanRect;
+      },
+    });
+  });
+
+  beforeEach(() => {
+    eleRect = { width: 100, height: 100 };
+    spanRect = { x: 0, y: 0, left: 0, top: 0, width: 1, height: 1 };
+    popupRect = { x: 0, y: 0, left: 0, top: 0, width: 100, height: 100 };
+    jest.useFakeTimers();
+  });
+
+  afterEach(() => {
+    cleanup();
+    jest.useRealTimers();
+  });
+
+  it('a suspended transition attempting popupVisible=false→true does not corrupt the dedup baseline; focusing the still-committed target emits exactly one onOpenChange(true)', async () => {
+    const onOpenChange = jest.fn();
+
+    // A never-resolving promise, so a `startTransition` that reaches this
+    // component stays pending indefinitely and React keeps the previous
+    // commit on screen.
+    const suspender: Promise<void> = new Promise(() => {});
+
+    // A child that either renders a Trigger-wired target (attempt=false)
+    // or throws the suspender (attempt=true). Forwards Trigger's injected
+    // DOM handlers onto the target span so `onFocus`/`onBlur` reach the
+    // Trigger's own action wiring.
+    const Child = React.forwardRef<
+      HTMLSpanElement,
+      { attempt: boolean } & React.HTMLAttributes<HTMLSpanElement>
+    >(({ attempt, ...rest }, ref) => {
+      if (attempt) {
+        throw suspender;
+      }
+      return <span ref={ref} className="target" tabIndex={0} {...rest} />;
+    });
+
+    const Harness: React.FC<{ open: boolean; attempt: boolean }> = ({
+      open,
+      attempt,
+    }) => (
+      <React.Suspense fallback={<span className="fallback" tabIndex={0} />}>
+        <Trigger
+          action={['focus']}
+          popup={<strong>popup</strong>}
+          popupVisible={open}
+          onOpenChange={onOpenChange}
+        >
+          <Child attempt={attempt} />
+        </Trigger>
+      </React.Suspense>
+    );
+
+    // Commit the initial state: closed, no throw. The committed target is
+    // what all subsequent focus events must land on.
+    const { container, rerender } = render(<Harness open={false} attempt={false} />);
+    await flush();
+
+    const committedTarget = container.querySelector('.target') as HTMLSpanElement;
+    expect(committedTarget).toBeTruthy();
+
+    // Attempt the transition: popupVisible=false → true, but the child
+    // throws the never-resolving suspender. Wrapping in `startTransition`
+    // tells React to keep the previous UI committed while this attempt
+    // pends. On a render-body-sync revision the speculative render would
+    // have written `true` to the dedup ref before suspending.
+    act(() => {
+      React.startTransition(() => {
+        rerender(<Harness open attempt />);
+      });
+    });
+    await flush();
+
+    // The originally committed target must still be in the DOM; the
+    // Suspense fallback should not have taken over because the transition
+    // is pending.
+    const stillCommitted = container.querySelector('.target') as HTMLSpanElement;
+    expect(stillCommitted).toBe(committedTarget);
+    expect(container.querySelector('.fallback')).toBeNull();
+
+    onOpenChange.mockClear();
+
+    // Focus the still-committed target. `action=['focus']` routes this to
+    // Trigger's `internalTriggerOpen(true)`. On the current fix the dedup
+    // ref was never written (useEffect only runs for committed renders,
+    // and the speculative render's render body never touched the ref), so
+    // this dispatch goes through cleanly.
+    act(() => {
+      fireEvent.focus(committedTarget);
+    });
+    await flush();
+
+    expect(onOpenChange).toHaveBeenCalledTimes(1);
+    expect(onOpenChange).toHaveBeenLastCalledWith(true);
+  });
+});

tests/layout-effect-ordering.test.tsx

@@ -0,0 +1,142 @@
+/**
+ * Regression coverage for the layout-effect ordering gap flagged in the
+ * #622 review by @nrps9909.
+ *
+ * The dedup baseline (`lastDispatchedOpenRef`) used to be synchronized inside
+ * Trigger's own `useLayoutEffect([rawOpen])`. React runs descendant layout
+ * effects *before* their parent's, so during a render that flipped
+ * `popupVisible` a descendant `useLayoutEffect` could reach
+ * `internalTriggerOpen` while the ref still held the previous, stale value —
+ * a legitimate opposite dispatch would then be discarded as a duplicate and
+ * `onOpenChange` would never fire.
+ *
+ * The fix synchronizes the ref during render, so descendant layout effects
+ * see the up-to-date baseline.
+ *
+ * Concrete scenario from the review:
+ *
+ * 1. Render a controlled `<Trigger hideAction={['focus']} popupVisible={false}>`
+ *    and focus the target.
+ * 2. Rerender with `popupVisible={true}`.
+ * 3. In the target component's `useLayoutEffect([open])`, call `target.blur()`.
+ * 4. Assert focus actually left the target *and* `onOpenChange(false)` fired
+ *    exactly once.
+ *
+ * Before the fix: focus leaves but the callback count is 0.
+ * After the fix: the callback fires once.
+ */
+import { act, cleanup, fireEvent, render } from '@testing-library/react';
+import { spyElementPrototypes } from '@rc-component/util/lib/test/domHook';
+import * as React from 'react';
+import Trigger from '../src';
+
+const flush = async () => {
+  for (let i = 0; i < 10; i += 1) {
+    act(() => {
+      jest.runAllTimers();
+    });
+    await act(async () => {
+      await Promise.resolve();
+    });
+  }
+};
+
+describe('Trigger.LayoutEffectOrdering (#622 review)', () => {
+  let eleRect = { width: 100, height: 100 };
+  let spanRect = { x: 0, y: 0, left: 0, top: 0, width: 1, height: 1 };
+  let popupRect = { x: 0, y: 0, left: 0, top: 0, width: 100, height: 100 };
+
+  beforeAll(() => {
+    spyElementPrototypes(HTMLElement, {
+      clientWidth: { get: () => eleRect.width },
+      clientHeight: { get: () => eleRect.height },
+      offsetWidth: { get: () => eleRect.width },
+      offsetHeight: { get: () => eleRect.height },
+      offsetParent: { get: () => document.body },
+    });
+    spyElementPrototypes(HTMLDivElement, {
+      getBoundingClientRect() {
+        return popupRect;
+      },
+    });
+    spyElementPrototypes(HTMLSpanElement, {
+      getBoundingClientRect() {
+        return spanRect;
+      },
+    });
+  });
+
+  beforeEach(() => {
+    eleRect = { width: 100, height: 100 };
+    spanRect = { x: 0, y: 0, left: 0, top: 0, width: 1, height: 1 };
+    popupRect = { x: 0, y: 0, left: 0, top: 0, width: 100, height: 100 };
+    jest.useFakeTimers();
+  });
+
+  afterEach(() => {
+    cleanup();
+    jest.useRealTimers();
+  });
+
+  it('accepts an opposite dispatch from a descendant layout effect after the parent commits a controlled open change', async () => {
+    const onOpenChange = jest.fn();
+
+    // Target that runs a layout effect on every `open` transition. When
+    // `open` becomes true it blurs itself synchronously — this executes
+    // *before* Trigger's own layout effects on the same commit, which is
+    // exactly the ordering window the original PR head mishandled.
+    // We fire a real blur event on the DOM node (not just `HTMLElement.blur()`)
+    // to ensure Trigger's `onBlur` handler runs under jsdom.
+    const Target = React.forwardRef<
+      HTMLSpanElement,
+      { open: boolean } & React.HTMLAttributes<HTMLSpanElement>
+    >(({ open, ...rest }, forwardedRef) => {
+      const localRef = React.useRef<HTMLSpanElement>(null);
+      React.useImperativeHandle(forwardedRef, () => localRef.current!);
+      React.useLayoutEffect(() => {
+        if (open && localRef.current) {
+          fireEvent.blur(localRef.current);
+        }
+      }, [open]);
+      // Forward any Trigger-injected handlers (onFocus/onBlur/etc.) onto
+      // the underlying span; without this, Trigger's `onBlur` never fires
+      // and the ordering gap can't be exercised.
+      return <span {...rest} className="target" ref={localRef} tabIndex={0} />;
+    });
+
+    const Harness: React.FC<{ open: boolean }> = ({ open }) => (
+      <Trigger
+        action={[]}
+        hideAction={['focus']}
+        popup={<strong>popup</strong>}
+        popupVisible={open}
+        onOpenChange={onOpenChange}
+      >
+        <Target open={open} />
+      </Trigger>
+    );
+
+    const { container, rerender } = render(<Harness open={false} />);
+    const target = container.querySelector('.target') as HTMLSpanElement;
+
+    act(() => {
+      fireEvent.focus(target);
+    });
+    await flush();
+
+    onOpenChange.mockClear();
+
+    // Parent commits false -> true. The descendant layout effect fires blur
+    // *during that commit*, before Trigger's own effects could have synced
+    // the dedup ref. With the render-body sync, Trigger sees the up-to-date
+    // baseline (`rawOpen === true`) and treats the blur-driven dispatch as
+    // a real transition to false.
+    act(() => {
+      rerender(<Harness open />);
+    });
+    await flush();
+
+    expect(onOpenChange).toHaveBeenCalledTimes(1);
+    expect(onOpenChange).toHaveBeenLastCalledWith(false);
+  });
+});