From 165c10fa33946eca9781d84f31ccab70eb3228d7 Mon Sep 17 00:00:00 2001
From: Nick Rogers <1903140+rogersnm@users.noreply.github.com>
Date: Mon, 14 Sep 2026 11:35:37 +0100
Subject: [PATCH] fix(overlay-editor): only motion keys schedule a commit

The overlay editor's keydown handler scheduled a zero-delay commit timer on
every key, not only Escape, Enter and Tab. When a person types quickly and
presses Enter, an ordinary key's timer can fire after Enter has set the
motion: it commits with no value and marks the edit finished, and Enter's
own timer then does nothing, so the typed value is discarded.

Return early for keys that are not a motion key, so only those schedule a
commit. Adds a test that fires a plain key and Enter before any timer runs.
---
 .../data-grid-overlay-editor.tsx              |  6 +++
 packages/core/test/data-editor.test.tsx       | 48 +++++++++++++++++++
 2 files changed, 54 insertions(+)

diff --git a/packages/core/src/internal/data-grid-overlay-editor/data-grid-overlay-editor.tsx b/packages/core/src/internal/data-grid-overlay-editor/data-grid-overlay-editor.tsx
index bac91ef44..94d280ed9 100644
--- a/packages/core/src/internal/data-grid-overlay-editor/data-grid-overlay-editor.tsx
+++ b/packages/core/src/internal/data-grid-overlay-editor/data-grid-overlay-editor.tsx
@@ -147,6 +147,12 @@ const DataGridOverlayEditor: React.FunctionComponent<DataGridOverlayEditorProps>
                 event.preventDefault();
                 customMotion.current = [event.shiftKey ? -1 : 1, 0];
                 save = true;
+            } else {
+                // Only a motion key may schedule a commit. Any other key's timer
+                // could fire after a fast Enter has set the motion, committing
+                // with no value and marking the edit finished, so the commit
+                // that follows would be dropped.
+                return;
             }
 
             window.setTimeout(() => {
diff --git a/packages/core/test/data-editor.test.tsx b/packages/core/test/data-editor.test.tsx
index 4a0d97369..ae83f87ac 100644
--- a/packages/core/test/data-editor.test.tsx
+++ b/packages/core/test/data-editor.test.tsx
@@ -1620,6 +1620,54 @@ describe("data-editor", () => {
         expect(document.body.contains(overlay)).toBe(false);
     });
 
+    test("Send edit when Enter follows another key before its timer fires", async () => {
+        const spy = vi.fn();
+        vi.useFakeTimers();
+        render(<DataEditor {...basicProps} onCellEdited={spy} />, {
+            wrapper: Context,
+        });
+        prep(false);
+
+        const canvas = screen.getByTestId("data-grid-canvas");
+        sendClick(canvas, {
+            clientX: 300, // Col B
+            clientY: 36 + 32 + 16, // Row 1 (0 indexed)
+        });
+
+        act(() => {
+            vi.runAllTimers();
+        });
+
+        fireEvent.keyDown(canvas, {
+            keyCode: 74,
+            key: "j",
+        });
+
+        act(() => {
+            vi.runAllTimers();
+        });
+
+        const overlay = screen.getByDisplayValue("j");
+
+        // A fast typist: the "k" keydown and Enter both land before any timer
+        // runs. The "k" timer must not commit on Enter's behalf with no value.
+        fireEvent.keyDown(overlay, {
+            keyCode: 75,
+            key: "k",
+        });
+        fireEvent.change(overlay, { target: { value: "jk" } });
+        fireEvent.keyDown(overlay, {
+            key: "Enter",
+        });
+
+        act(() => {
+            vi.runAllTimers();
+        });
+
+        expect(spy).toBeCalledWith([1, 1], expect.objectContaining({ data: "jk" }));
+        expect(document.body.contains(overlay)).toBe(false);
+    });
+
     test("Send edit with click off", async () => {
         const spy = vi.fn();
         vi.useFakeTimers();