[lexical][lexical-clipboard] Bug Fix: Preserve alignment when pasting selected text by Rohithmatham12 · Pull Request #8671 · facebook/lexical

Rohithmatham12 · 2026-06-10T19:00:39Z

Description

When copying selected text from an aligned paragraph inside the same Lexical namespace, the application/x-lexical-editor clipboard payload took priority over text/html. That JSON payload only contained the selected TextNode, so pasting into another paragraph reused the destination paragraph's default alignment and discarded the source paragraph alignment.

This updates clipboard JSON export to retain the non-inline parent element when the selected child content covers the full element text. That preserves block-level formatting such as paragraph alignment for full-paragraph text selections while partial text selections remain text-only.

Closes #8101

Test plan

Before

Copying all visible text from an aligned paragraph and pasting it elsewhere lost the source paragraph alignment.

After

Full-paragraph text selections preserve block-level alignment on paste, including paragraphs that contain inline elements such as links, while partial text selections remain text-only.

Automated tests:

node node_modules/vitest/vitest.mjs --project unit packages/lexical/src/__tests__/unit/HTMLCopyAndPaste.test.ts --run
node node_modules/vitest/vitest.mjs --project unit packages/lexical-clipboard/src/__tests__/unit/GetClipboardDataExtension.test.ts packages/lexical-clipboard/src/__tests__/unit/ClipboardImportExtension.test.ts --run
node node_modules/prettier/bin/prettier.cjs --check packages/lexical-clipboard/src/clipboard.ts packages/lexical/src/__tests__/unit/HTMLCopyAndPaste.test.ts
node node_modules/eslint/bin/eslint.js packages/lexical-clipboard/src/clipboard.ts packages/lexical/src/__tests__/unit/HTMLCopyAndPaste.test.ts

vercel · 2026-06-10T19:00:45Z

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Project	Deployment	Actions	Updated (UTC)
lexical	Ready	Preview, Comment	Jun 23, 2026 12:22am
lexical-playground	Ready	Preview, Comment	Jun 23, 2026 12:22am

potatowagon

Reviewed by Navi (Tater Thoughts Bobblehead) on behalf of @potatowagon.

Assessment: LGTM with minor note ✅

What this does: Fixes #8101 — when copying text from an aligned paragraph within the same Lexical editor, the application/x-lexical-editor clipboard JSON only contained the TextNode, losing block-level formatting (alignment, indent). The fix adds $shouldIncludeElementWithSelectedChildren() which includes the parent element in the clipboard payload when the selected children cover the full element text content.

What I checked:

Logic correctness: The function checks: (a) is range selection, (b) node is non-inline ElementNode, (c) not root, (d) selectedNodes content under this parent matches the parent's full text content. This correctly identifies "entire paragraph selected" without false positives on partial selections.
Edge cases considered:
- Partial text selection → selectedTextContent !== node.getTextContent() → returns false ✅
- Empty paragraph → selectedTextContent !== "" guard → returns false ✅
- Inline elements (links, marks) → node.isInline() guard → skipped ✅
- Root node → $isRootNode(node) guard → skipped ✅
- Multiple children in paragraph (e.g. bold+plain) → uses $sliceSelectedTextNodeContent per node → correct ✅
Performance note: The function iterates selectedNodes and calls isParentOf() for each. For very large selections this is O(n×depth), but clipboard operations are user-initiated and typically small. Acceptable.
Test coverage: Good test — creates a centered paragraph, copies via $getClipboardDataFromSelection, pastes into another paragraph, asserts alignment is preserved in DOM output.
www compat: No API signature changes. $shouldIncludeElementWithSelectedChildren is module-private. The behavioral change (richer clipboard payload) is strictly additive — paste targets that ignore element wrappers will work as before.

One observation: The text-content comparison (selectedTextContent === node.getTextContent()) is a heuristic — it could theoretically match if a partial selection happens to produce the same string as the full element (e.g., repeated characters). This is an extremely unlikely edge case and the consequence (including alignment where it shouldn't) is benign.

CI: CLA ✅, Vercel ✅. Full test matrix pending (PR is ~30min old). Recommend waiting for unit green.

Ready to approve once full CI passes.

etrepum · 2026-06-11T04:45:48Z

Title and description doesn't match the pull request template

mayrang · 2026-06-21T15:52:22Z

The approach makes sense, but $shouldIncludeElementWithSelectedChildren breaks on paragraphs containing inline elements (links, marks, etc.). selection.getNodes() includes intermediate element nodes, so their getTextContent() gets double-counted in the join — e.g. "Hello worldworld" vs "Hello world". Tested locally and confirmed the alignment isn't preserved when a link is present.

Details and a suggested fix inline. Also noted how HeadingNode handles the same problem via extractWithChild for reference.

mayrang · 2026-06-21T15:52:33Z

+  if (selectedNodes.length === 0) {
+    return false;
+  }
+  const selectedTextContent = selectedNodes


selection.getNodes() returns intermediate element nodes too — e.g. for "Hello " + <a>world</a>, it returns [TextNode, LinkNode, TextNode]. The join then produces "Hello worldworld" (LinkNode's getTextContent() + child TextNode), which never matches the paragraph's "Hello world". So this function returns false for any paragraph containing links, marks, or other inline elements.

Filtering to leaf nodes (e.g. .filter(n => !$isElementNode(n))) before the comparison would fix it.

mayrang · 2026-06-21T15:53:00Z


  if (shouldInclude && !shouldExclude) {
    targetArray.push(serializedNode);
+  } else if (


For context — HeadingNode already overrides extractWithChild to return true, so heading alignment is preserved on copy without needing this new function. ParagraphNode doesn't override it (defaults to false), which is why paragraph formatting gets stripped.

The full-text check makes sense if you only want full-paragraph selections to carry alignment. Just noting the existing mechanism since it covers a related case.

mayrang · 2026-06-21T15:53:14Z

+
+          target.select(0, target.getChildrenSize());
+
+          const selection = $getSelection();


target.select() returns RangeSelection directly — the $getSelection() + invariant($isRangeSelection) round-trip can be replaced with const selection = target.select(0, target.getChildrenSize()).

const selection = target.select(0) is also sufficient, the default for both select arguments is the end (target.select() and target.selectEnd() are equivalent)

Rohithmatham12 · 2026-06-21T20:28:41Z

Addressed the review feedback in 752a47ecc:

filtered selected intermediate ElementNodes out of $shouldIncludeElementWithSelectedChildren() so inline elements like links are not double-counted
added regression coverage for preserving centered paragraph alignment when the selected paragraph contains a link
simplified the paste target selection to use the RangeSelection returned by target.select()

Re-ran:

node node_modules/vitest/vitest.mjs --project unit packages/lexical/src/__tests__/unit/HTMLCopyAndPaste.test.ts --run
node node_modules/vitest/vitest.mjs --project unit packages/lexical-clipboard/src/__tests__/unit/GetClipboardDataExtension.test.ts packages/lexical-clipboard/src/__tests__/unit/ClipboardImportExtension.test.ts --run
node node_modules/prettier/bin/prettier.cjs --check packages/lexical-clipboard/src/clipboard.ts packages/lexical/src/__tests__/unit/HTMLCopyAndPaste.test.ts
node node_modules/eslint/bin/eslint.js packages/lexical-clipboard/src/clipboard.ts packages/lexical/src/__tests__/unit/HTMLCopyAndPaste.test.ts

Preserve alignment when pasting selected text

372d9ba

Rohithmatham12 requested review from acywatson, etrepum, fantactuka, ivailop7, potatowagon and zurfyx as code owners June 10, 2026 19:00

meta-cla Bot added the CLA Signed This label is managed by the Facebook bot. Authors need to sign the CLA before a PR can be reviewed. label Jun 10, 2026

vercel Bot deployed to Preview – lexical-playground June 10, 2026 19:01 View deployment

vercel Bot deployed to Preview – lexical June 10, 2026 19:02 View deployment

potatowagon reviewed Jun 10, 2026

View reviewed changes

etrepum added the extended-tests Run extended e2e tests on a PR label Jun 10, 2026

Rohithmatham12 changed the title ~~Preserve alignment when pasting selected text~~ [lexical][lexical-clipboard] Bug Fix: Preserve alignment when pasting selected text Jun 11, 2026

mayrang reviewed Jun 21, 2026

View reviewed changes

Handle inline elements in clipboard alignment

752a47e

vercel Bot deployed to Preview – lexical-playground June 21, 2026 20:27 View deployment

vercel Bot deployed to Preview – lexical June 21, 2026 20:28 View deployment

Simplify paste target selection

c8f0215

vercel Bot deployed to Preview – lexical-playground June 23, 2026 00:21 View deployment

vercel Bot deployed to Preview – lexical June 23, 2026 00:22 View deployment

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[lexical][lexical-clipboard] Bug Fix: Preserve alignment when pasting selected text#8671

[lexical][lexical-clipboard] Bug Fix: Preserve alignment when pasting selected text#8671
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Rohithmatham12:preserve-pasted-alignment

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		target.select(0, target.getChildrenSize());

		const selection = $getSelection();

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