fix(app): defer composer updates during IME composition (#3462)

* fix(app): defer composer updates during IME composition

* fix(app): read live DOM value from web composer getText

---------

Co-authored-by: Mohamed Boudra <boudra.moha@gmail.com>

packages/app/src/composer/input/text-input.web.browser.test.tsx

@@ -2,11 +2,13 @@ import React, { act } from "react";
 import { createRoot, type Root } from "react-dom/client";
 import { afterEach, describe, expect, it } from "vitest";
 import { ComposerTextInput } from "./text-input.web";
+import type { ComposerTextInputHandle } from "./text-input-types";
 
 interface MountedInput {
   root: Root;
   container: HTMLDivElement;
   textarea: HTMLTextAreaElement;
+  inputRef: React.MutableRefObject<ComposerTextInputHandle | null>;
 }
 
 interface TextRecorder {
@@ -16,7 +18,10 @@ interface TextRecorder {
 
 const mountedInputs: MountedInput[] = [];
 
-function mountInput(onChangeText: (text: string) => void): MountedInput {
+function mountInput(
+  onChangeText: (text: string) => void,
+  inputRef: React.MutableRefObject<ComposerTextInputHandle | null> = React.createRef(),
+): MountedInput {
   const container = document.createElement("div");
   document.body.appendChild(container);
   const root = createRoot(container);
@@ -24,6 +29,7 @@ function mountInput(onChangeText: (text: string) => void): MountedInput {
   act(() => {
     root.render(
       <ComposerTextInput
+        ref={inputRef}
         text=""
         multiline={true}
         onChangeText={onChangeText}
@@ -37,7 +43,7 @@ function mountInput(onChangeText: (text: string) => void): MountedInput {
     throw new Error("Composer text input did not render a textarea");
   }
 
-  const mounted = { root, container, textarea };
+  const mounted = { root, container, textarea, inputRef };
   mountedInputs.push(mounted);
   return mounted;
 }
@@ -147,16 +153,44 @@ describe("ComposerTextInput web IME composition", () => {
     expect(mounted.textarea.value).toBe("你好");
   });
 
-  it("does not report committed text twice when the input event already reported it", () => {
+  it("defers Korean IME input events until composition commits", () => {
     const changes: string[] = [];
     const mounted = mountInput((text) => changes.push(text));
 
     act(() => {
       dispatchComposition(mounted.textarea, "compositionstart");
-      typeFromIme(mounted.textarea, "你好");
+      typeFromIme(mounted.textarea, "ㅎ");
+      typeFromIme(mounted.textarea, "하");
+      typeFromIme(mounted.textarea, "한");
+    });
+
+    expect(changes).toEqual([]);
+
+    act(() => {
       dispatchComposition(mounted.textarea, "compositionend");
     });
 
-    expect(changes).toEqual(["你好"]);
+    expect(changes).toEqual(["한"]);
+  });
+
+  it("reads the live DOM value for send-path text extraction during composition", () => {
+    const inputRef = React.createRef<ComposerTextInputHandle>();
+    const mounted = mountInput(ignoreTextChange, inputRef);
+    let queuedText = "";
+
+    act(() => {
+      dispatchComposition(mounted.textarea, "compositionstart");
+      typeFromIme(mounted.textarea, "old한");
+      queuedText = mounted.inputRef.current?.getText() ?? "";
+    });
+
+    expect(queuedText).toBe("old한");
+    expect(mounted.textarea.value).toBe("old한");
+
+    act(() => {
+      mounted.inputRef.current?.replaceText("");
+    });
+
+    expect(mounted.textarea.value).toBe("");
   });
 });

packages/app/src/composer/input/text-input.web.tsx

@@ -6,8 +6,11 @@ import type { ComposerTextInputHandle, ComposerTextInputProps } from "./text-inp
 interface WebTextInputElement extends TextInput {
   value?: string;
   setSelectionRange?: (start: number, end: number) => void;
-  addEventListener: (type: "compositionend", listener: EventListener) => void;
+  addEventListener: (type: "compositionstart" | "compositionend", listener: EventListener) => void;
-  removeEventListener: (type: "compositionend", listener: EventListener) => void;
+  removeEventListener: (
+    type: "compositionstart" | "compositionend",
+    listener: EventListener,
+  ) => void;
 }
 
 const ThemedTextInput = withUnistyles(TextInput, (theme) => ({
@@ -21,6 +24,7 @@ export const ComposerTextInput = forwardRef<ComposerTextInputHandle, ComposerTex
   ) {
     const inputRef = useRef<TextInput | null>(null);
     const textRef = useRef(text);
+    const isComposingRef = useRef(false);
     const onChangeTextRef = useRef(onChangeText);
     onChangeTextRef.current = onChangeText;
 
@@ -28,7 +32,11 @@ export const ComposerTextInput = forwardRef<ComposerTextInputHandle, ComposerTex
       const input = inputRef.current as WebTextInputElement | null;
       if (!input) return;
 
+      const startComposition = () => {
+        isComposingRef.current = true;
+      };
       const endComposition = () => {
+        isComposingRef.current = false;
         const nextText = input.value ?? "";
         if (nextText !== textRef.current) {
           textRef.current = nextText;
@@ -36,14 +44,17 @@ export const ComposerTextInput = forwardRef<ComposerTextInputHandle, ComposerTex
         }
       };
 
+      input.addEventListener("compositionstart", startComposition);
       input.addEventListener("compositionend", endComposition);
       return () => {
+        input.removeEventListener("compositionstart", startComposition);
         input.removeEventListener("compositionend", endComposition);
       };
     }, []);
 
     const handleChangeText = useCallback(
       (nextText: string) => {
+        if (isComposingRef.current) return;
         if (nextText === textRef.current) return;
         textRef.current = nextText;
         onChangeText(nextText);
@@ -54,7 +65,14 @@ export const ComposerTextInput = forwardRef<ComposerTextInputHandle, ComposerTex
     useImperativeHandle(ref, () => ({
       focus: () => inputRef.current?.focus(),
       blur: () => inputRef.current?.blur(),
-      getText: () => textRef.current,
+      getText: () => {
+        const input = inputRef.current as WebTextInputElement | null;
+        const nextText = input?.value ?? textRef.current;
+        if (nextText !== textRef.current) {
+          textRef.current = nextText;
+        }
+        return nextText;
+      },
       replaceText: (nextText, selection) => {
         textRef.current = nextText;
         const input = inputRef.current as WebTextInputElement | null;