fix: prevent table column insertion from freezing

[Bashar-Omar]

Fixes #982.

Column insertion was updating the table while the column popover was still in the same interaction. Since inserting a column changes the header geometry, the popover trigger moves while Radix is positioning it and React falls into repeated updates.

This closes the column popover first and defers the Lexical table mutation to the next task. The existing node-by-key guard and focus behavior stay unchanged.

Added browser coverage for inserting columns on both sides. Before the fix, both cases timed out with Maximum update depth exceeded in Chromium, Firefox, and WebKit. After the fix, the full CI suite passes.

[github-actions]

🎉 This PR is included in version 4.3.0 🎉

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

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[petyosi]

Thanks for the reproduction and the browser test, @Bashar-Omar. This shipped in v4.3.0, but with a different fix on top of yours, so here is why the setTimeout is no longer in TableEditor.tsx.

While looking into this further, it turned out to be a regression from two earlier changes combined:

• The editor now renders decorators through Lexical's extension composer, which uses useSyncExternalStore instead of the older flushSync-based decorator hook.
• A later fix moved setActiveCellWithBoundaries inside parentEditor.update().

With both in place, React rendered the new active cell ([0, 0]) against the old table first and focused the cell that was about to shift right. Its late focus event then claimed the active position back from the new cell, and the two cell editors kept taking focus from each other until React hit "Maximum update depth exceeded". Rows were not affected because <tr> elements are keyed by index, so the shifted cells remount instead of sending stale focus events.

The fix in 5408665 sets the active cell from the update's onUpdate callback, which runs after the commit. That removes the need to defer the mutation or control the popover (it closes on its own once focus moves to the new cell). The same change covers insert row and the add-row/add-column buttons, and it fixes two related bugs: inserting right of the last column or below the last row moved focus to the wrong cell.

Your table-column-insertion.spec.ts is still in place and guards the regression. Thanks again for the contribution!

[Bashar-Omar]

Thanks for the detailed breakdown. Moving the active-cell update to onUpdate after the Lexical commit makes the ordering issue much clearer than my initial popover hypothesis. Glad the browser regression test was useful, and nice catch on the last-row/last-column focus cases as well.