Decouple edit-session UI close from the data-commit/cleanup phase

[Copilot]

JsonEditor awaits onUpdate before committing, but closes the editor synchronously before the await — so during a deferred commit (confirm-modal hook, slow remote round-trip) value nodes flash the new typed value as if applied, and collection nodes re-derive children from the old data. The naive fix (move closeEdit into .then) breaks Tab-commit by running a stale cancelOp against the just-committed value, double-fires terminal events, and closes the wrong session.

Two-phase commit in the editing store

src/contexts/EditingProvider.tsx — splits closeEdit's coupled responsibilities:

• beginCommit() — clears cancelOp synchronously (keeps Tab-commit safe) and registers the active path in a committingPaths set. Leaves currentlyEditingElement in place, so isEditing stays true and the editor stays visible.
• endCommit(path) — deregisters and clears currentlyEditingElement only if it still points at path. A Tab-driven startEdit(next) during the pending window leaves the new session untouched.
• startEdit's displacement logic skips its cancelEdit/cancelRename emit for any session in committingPaths — the node owns the terminal event from its own commit outcome, no double-fire.

Node commit handlers

• src/ValueNodeWrapper.tsx — handleEdit uses beginCommit() synchronously and endCommit(path) in the resolve callback. The local value buffer naturally retains the user's typed value through the pending window.
• src/CollectionNode.tsx — same shape, plus the JSON buffer (stringifiedValue) is now cleared in the resolve callback rather than synchronously, so the open textarea keeps showing the typed JSON instead of re-deriving from old data.

const handleEdit = (inputValue?: unknown) => {
  beginCommit()              // sync: clear cancelOp, mark path mid-commit
  setPreviousValue(null)
  // ...derive newValue...
  onEdit(newValue, path).then((result) => {
    handleMutationResult({ result, /* confirmEdit | revert + cancelEdit */ })
    endCommit(path)          // close session iff still ours
  })
}

Secondary edit paths (type-change, rename, add) keep the existing synchronous closeEdit() — they don't surface the optimistic-display window in practice and the buffer mechanics differ. Worth a follow-up if uniformity becomes desirable.

Tests

test/JsonEditor.test.tsx adds three regressions against a Promise resolved on demand:

• value edit stays open while pending; resolve fires confirmEdit and closes.
• value edit reject reverts the display and closes.
• collection JSON buffer survives the pending window.

Existing Tab-commit / displaced-session / editorRef.cancel guards still pass — the three documented failure modes (Tab-commit revert, double terminal events, wrong-session close) are covered.

[github-actions]

Bundle size impact

json-edit-react

Format	Base raw	PR raw	Δ raw	Base gzip	PR gzip	Δ gzip
esm	54.18 KB	54.50 KB	🔺 +330 B (+0.59%)	18.94 KB	19.03 KB	🔺 +95 B (+0.49%)
cjs	55.66 KB	55.99 KB	🔺 +335 B (+0.59%)	19.01 KB	19.11 KB	🔺 +104 B (+0.53%)

_{Measured from build/index.{cjs,esm}.js. Gzip at level 9.}

[CarlosNZ]

Replaced by #330