[lexical-react] Bug Fix: the node context menu leaves the native menu alone when it has nothing to show

[LeSingh1]

Description

NodeContextMenuPlugin suppresses the browser's context menu and opens its own before it knows whether it has anything to put in it:

function onContextMenu(e: MouseEvent) {
  e.preventDefault();          // <- unconditional
  refs.setPositionReference({ ... });

  let visibleItems: ContextMenuType[] = [];
  if (items) {
    editor.read(() => {
      const node = $getNearestNodeFromDOMNode(e.target as Element) ?? $getRoot();
      if (node) {
        visibleItems = items!.filter(option =>
          option.$showOn ? option.$showOn(node) : true,
        );
      }
    });
  }
  ...
  setIsOpen(true);             // <- unconditional
}

$showOn is documented as the per-node predicate that decides "whether the item is shown for the right-clicked node", so it is expected that a given node hides some items — and a node that hides all of them is the natural consequence of that, not a misuse. When it happens the user gets the worst of both: no native menu, because preventDefault already ran; no visible menu, because the rendered <div> has no children; and the page cannot be scrolled, because the plugin still mounts

<FloatingOverlay lockScroll={true}>

around it. The only way out is to click somewhere to dismiss an overlay that shows nothing. Right-clicking to reach Copy, Paste, or Inspect on such a node is simply not possible.

This computes visibleItems first and returns early when it is empty, before preventDefault and before setIsOpen(true). Everything else is unchanged; the item-building code just moves below the filter it always depended on. No API or serialization change.

Test plan

New unit test packages/lexical-react/src/__tests__/unit/LexicalNodeContextMenuPlugin.test.tsx. The second case is the control — the menu must still replace the native one when it does have an item — and passes before and after.

Before

 ❯ packages/lexical-react/src/__tests__/unit/LexicalNodeContextMenuPlugin.test.tsx (2 tests | 1 failed)
   × leaves the native context menu alone when no item is shown
     AssertionError: expected true to be false // Object.is equality
   ✓ opens and replaces the native context menu when an item is shown

 Test Files  1 failed (1)
      Tests  1 failed | 1 passed (2)

After

 Test Files  1 passed (1)
      Tests  2 passed (2)

Package suite is unchanged:

$ npx vitest run packages/lexical-react
 Test Files  32 passed (32)
      Tests  184 passed (184)

[vercel]

@LeSingh1 is attempting to deploy a commit to the Meta Open Source Team on Vercel.

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[LeSingh1]

Consolidated into #9051 with the other PRs that share this defect, per @etrepum's note on #9027 and @mayrang's on #9035. Same fix and same tests, one review.