[WIP][lexical-rich-text][lexical-playground] Bug Fix: Prevent unnecessary history entries on DELETE_CHARACTER_COMMAND

packages/lexical-playground/__tests__/e2e/Headings/HeadingsBackspaceAtStart.spec.mjs

@@ -56,3 +56,85 @@ test('Headings - stays as a heading when you backspace at the start of a heading
     `,
   );
 });
+
+test('Headings - converts to paragraph when backspace at start of empty heading', async ({
+  page,
+  isPlainText,
+  isCollab,
+}) => {
+  test.skip(isPlainText);
+  await initialize({isCollab, page});
+  await focusEditor(page);
+
+  await click(page, '.block-controls');
+  await click(page, '.dropdown .icon.h1');
+
+  await assertHTML(
+    page,
+    html`
+      <h1 class="PlaygroundEditorTheme__h1">
+        <br />
+      </h1>
+    `,
+  );
+
+  await page.keyboard.press('Backspace');
+
+  await assertHTML(
+    page,
+    html`
+      <p class="PlaygroundEditorTheme__paragraph">
+        <br />
+      </p>
+    `,
+  );
+});
+
+test('Headings - does not create unnecessary history entries when backspace at start of heading with content', async ({
+  page,
+  isPlainText,
+  isCollab,
+}) => {
+  test.skip(isPlainText);
+  await initialize({isCollab, page});
+  await focusEditor(page);
+
+  // Create an empty heading
+  await click(page, '.block-controls');
+  await click(page, '.dropdown .icon.h1');
+
+  // This is our meaningful change that should be undoable
+  await page.keyboard.type('Welcome to the playground');
+
+  await moveToEditorBeginning(page);
+
+  // These backspace operations should not create history entries
+  await page.keyboard.press('Backspace');
+  await page.keyboard.press('Backspace');
+  await page.keyboard.press('Backspace');
+
+  // Verify content is unchanged after backspace attempts
+  await assertHTML(
+    page,
+    html`
+      <h1
+        class="PlaygroundEditorTheme__h1 PlaygroundEditorTheme__ltr"
+        dir="ltr">
+        <span data-lexical-text="true">Welcome to the playground</span>
+      </h1>
+    `,
+  );
+
+  // Press undo - should undo the typing since backspace didn't create history entries
+  await page.keyboard.press('Meta+z');
+
+  // Should revert to empty heading since that was the state before typing
+  await assertHTML(
+    page,
+    html`
+      <h1 class="PlaygroundEditorTheme__h1">
+        <br />
+      </h1>
+    `,
+  );
+});

packages/lexical-rich-text/src/index.ts

@@ -379,9 +379,10 @@ export class HeadingNode extends ElementNode {
   }
 
   collapseAtStart(): true {
-    const newElement = !this.isEmpty()
-      ? $createHeadingNode(this.getTag())
-      : $createParagraphNode();
+    if (!this.isEmpty()) {
+      return true;
+    }
+    const newElement = $createParagraphNode();
     const children = this.getChildren();
     children.forEach((child) => newElement.append(child));
     this.replace(newElement);