fix(ui): preserve composer paste undo history

apps/desktop/e2e/composer-undo.spec.ts

@@ -0,0 +1,143 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import type { Locator } from '@playwright/test';
+import { expect, test, COMPOSER_INPUT } from './fixtures';
+
+const TYPED = 'x';
+const PASTED = '中文 <tag>& "quoted"\r\nhttps://example.test/path?x=1&y=2\n第二行 <>&';
+const PASTED_AS_PLAIN_TEXT = PASTED.replace(/\r\n/g, '\n');
+const UNDO_SHORTCUT = process.platform === 'darwin' ? 'Meta+z' : 'Control+z';
+
+async function expectComposerText(
+  composer: Locator,
+  expected: string,
+): Promise<void> {
+  await expect
+    .poll(() => composer.evaluate((element) => element.innerText.replace(/\r\n/g, '\n')))
+    .toBe(expected);
+}
+
+async function pastePlainText(composer: Locator, pasted: string): Promise<void> {
+  await composer.evaluate((element, text) => {
+    const transfer = new DataTransfer();
+    transfer.setData('text/plain', text);
+    element.dispatchEvent(
+      new ClipboardEvent('paste', {
+        bubbles: true,
+        cancelable: true,
+        clipboardData: transfer,
+      }),
+    );
+  }, pasted);
+}
+
+test('plain-text paste is undone separately from prior typing', async ({ window: page }) => {
+  const composer = page.locator(COMPOSER_INPUT);
+
+  await composer.click();
+  await page.keyboard.type(TYPED);
+  await expectComposerText(composer, TYPED);
+
+  await pastePlainText(composer, PASTED);
+  await expectComposerText(composer, `${TYPED}${PASTED_AS_PLAIN_TEXT}`);
+
+  await page.keyboard.press(UNDO_SHORTCUT);
+  await expectComposerText(composer, TYPED);
+
+  await page.keyboard.press(UNDO_SHORTCUT);
+  await expectComposerText(composer, '');
+
+  await page.keyboard.press(UNDO_SHORTCUT);
+  await expectComposerText(composer, '');
+});
+
+test('pasted absolute path sends on the first Enter without opening the slash menu', async ({
+  window: page,
+}) => {
+  const composer = page.locator(COMPOSER_INPUT);
+  const pasted = '/Users/me/notes.txt';
+
+  await expect(page.locator('button.maka-workspace-picker')).toBeEnabled();
+  await composer.click();
+  await pastePlainText(composer, pasted);
+
+  await expect(composer).toHaveAttribute('aria-expanded', 'false');
+  await composer.press('Enter');
+  await expect(page.getByText(`Fake backend received: ${pasted}`)).toBeVisible();
+});
+
+test('pasted mention-looking text does not open the file menu', async ({ window: page }) => {
+  const composer = page.locator(COMPOSER_INPUT);
+
+  await expect(page.locator('button.maka-workspace-picker')).toBeEnabled();
+  await composer.click();
+  await pastePlainText(composer, 'review @name');
+
+  await expect(composer).toHaveAttribute('aria-expanded', 'false');
+  await expect(page.getByRole('listbox')).toHaveCount(0);
+});
+
+test('plain-text paste closes an existing trigger menu before the first Enter', async ({
+  window: page,
+}) => {
+  const composer = page.locator(COMPOSER_INPUT);
+  const pasted = 'Users/me/notes.txt';
+
+  await expect(page.locator('button.maka-workspace-picker')).toBeEnabled();
+  await composer.click();
+  await composer.pressSequentially('/');
+  await expect(composer).toHaveAttribute('aria-expanded', 'true');
+
+  await pastePlainText(composer, pasted);
+
+  await expect(composer).toHaveAttribute('aria-expanded', 'false');
+  await composer.press('Enter');
+  await expect(page.getByText(`Fake backend received: /${pasted}`)).toBeVisible();
+});
+
+test('plain-text paste synchronizes the controlled draft once', async ({ window: page }) => {
+  const composer = page.locator(COMPOSER_INPUT);
+
+  await expect(page.locator('button.maka-workspace-picker')).toBeEnabled();
+  await page.evaluate(() => {
+    const storageKey = 'maka-new-task-reload-intent-v1';
+    sessionStorage.setItem(storageKey, JSON.stringify({ draft: '' }));
+    const originalSetItem = Storage.prototype.setItem;
+    let writes = 0;
+    Storage.prototype.setItem = function setItem(key: string, value: string): void {
+      if (key === storageKey) writes += 1;
+      originalSetItem.call(this, key, value);
+    };
+    Object.defineProperty(globalThis, '__makaComposerDraftWrites', {
+      configurable: true,
+      get: () => writes,
+    });
+  });
+
+  await composer.click();
+  await pastePlainText(composer, 'one controlled change');
+
+  const writes = await page.evaluate(
+    () =>
+      (globalThis as typeof globalThis & { __makaComposerDraftWrites?: number })
+        .__makaComposerDraftWrites ?? 0,
+  );
+  expect(writes).toBe(1);
+});

packages/ui/src/composer.tsx

@@ -478,6 +478,7 @@ export const Composer = forwardRef<
   const composerMountedRef = useMountedRef();
   const sendPendingRef = useRef(false);
   const compositionActiveRef = useRef(false);
+  const plainTextPasteInputActiveRef = useRef(false);
   const importActionOwnerRef = useRef<ChatInputActionOwner<ComposerImportActionId> | null>(null);
   if (!importActionOwnerRef.current) {
     importActionOwnerRef.current = createChatInputActionOwner((action) => {
@@ -1681,6 +1682,9 @@ export const Composer = forwardRef<
           input={(
             <div
               className="maka-composer-input"
+              onInputCapture={(event) => {
+                if (plainTextPasteInputActiveRef.current) event.stopPropagation();
+              }}
               // PR-FE-BUG-HUNT-10: a paste that lands mid-CJK-composition must
               // not be consumed — `ChatComposerInput` always preventDefault()s
               // the paste, which would interrupt the IME mid-character. The
@@ -1711,6 +1715,36 @@ export const Composer = forwardRef<
                 hasHistory={false}
                 triggers={triggers}
                 pasteAsToken={pasteAsToken}
+                onPaste={(event, pasted) => {
+                  // Astryx has already offered token-adjacent, file, and
+                  // reference-sized-token pastes before it reaches this seam.
+                  const plainTextContainer = document.createElement('div');
+                  plainTextContainer.textContent = pasted;
+                  const menuWasOpen = event.currentTarget.getAttribute('aria-expanded') === 'true';
+                  plainTextPasteInputActiveRef.current = true;
+                  try {
+                    // Deprecated, but still the composer's only insertion
+                    // primitive that creates a browser undo transaction.
+                    // Migrate when Astryx exposes a transactional plain-text
+                    // insertion authority.
+                    return document.execCommand(
+                      'insertHTML',
+                      false,
+                      plainTextContainer.innerHTML.replace(/\r\n?|\n/g, '<br>'),
+                    );
+                  } finally {
+                    plainTextPasteInputActiveRef.current = false;
+                    if (menuWasOpen) {
+                      event.currentTarget.dispatchEvent(
+                        new KeyboardEvent('keydown', {
+                          key: 'Escape',
+                          bubbles: true,
+                          cancelable: true,
+                        }),
+                      );
+                    }
+                  }
+                }}
                 onFiles={onInputFiles}
                 onKeyDown={onInputKeyDown}
                 onCompositionStart={() => { compositionActiveRef.current = true; }}