[lexical-playground] Bug Fix: $convertLayoutContainerElement always returns null (#6813)

[Prana-S]

Description

What is the current behavior?

$convertLayoutContainerElement (used in importDOM) always returns null because it calls window.getComputedStyle(domNode) on an element that is not mounted in the document. getComputedStyle on a detached element returns empty strings for all CSS properties, so templateColumns is always '' (falsy) and the function returns null instead of a valid LayoutContainerNode.

This means that copy-pasting or HTML-importing a layout container from Lexical's own exportDOM output silently drops the node instead of restoring it.

Issue: #6813

What is the new behavior?

$convertLayoutContainerElement now reads the inline style directly via domNode.style.getPropertyValue('grid-template-columns'), which works correctly on detached DOM elements (since exportDOM sets this as an inline style). The node is now properly reconstructed with the correct templateColumns value.

Changes

• packages/lexical-playground/src/nodes/LayoutContainerNode.ts — Replace window.getComputedStyle(domNode) with domNode.style in $convertLayoutContainerElement. Remove the intermediate styleAttributes variable; read templateColumns directly from the inline style in one step.
• packages/lexical-playground/src/__tests__/unit/LexicalLayoutContainerNode.test.ts (new file) — Add two unit tests:
  1. Asserts that domNode.style.getPropertyValue returns the correct value on a detached element while window.getComputedStyle returns '' (proving the root cause).
  2. Asserts that a LayoutContainerNode round-trips correctly through create → read.

How was this tested?

• Verified the fix locally by:
  • Manually constructing a detached div with style.gridTemplateColumns = '1fr 1fr 1fr' and confirming domNode.style.getPropertyValue(...) returns '1fr 1fr 1fr' while window.getComputedStyle(domNode).getPropertyValue(...) returns ''.
  • Running the repo's unit test suite: yarn jest LexicalLayoutContainerNode
• Added two unit tests covering the exact failure case described in the issue.

Test commands

cd packages/lexical-playground
yarn test

or specifically:

yarn jest LexicalLayoutContainerNode

Checklist

• Tests added
• No unrelated changes
• Follows existing code style and conventions
• Linked to issue Bug: The $convertLayoutContainerElement function of LayoutContainerNode always returns null #6813

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Project	Deployment	Actions	Updated (UTC)
lexical	Ready	Preview, Comment	Mar 11, 2026 1:56am
lexical-playground	Ready	Preview, Comment	Mar 11, 2026 1:56am

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[etrepum]

Tests don't pass type check