fix(hotkeys): ignore keydown events whose target is not an element

frontend/src/hooks/hotkeys/__tests__/useKeyboardHotkeys.test.tsx

@@ -73,4 +73,21 @@ describe('KeyboardHotkeysProvider', () => {
 
 		expect(handleShortcut).not.toHaveBeenCalled();
 	});
+
+	it('ignores keydown events dispatched on document itself', () => {
+		const handleShortcut = jest.fn();
+
+		render(
+			<KeyboardHotkeysProvider>
+				<TestComponentWithRegister handleShortcut={handleShortcut} />
+			</KeyboardHotkeysProvider>,
+		);
+
+		expect(() =>
+			document.dispatchEvent(new KeyboardEvent('keydown', { key: 'a' })),
+		).not.toThrow();
+		document.dispatchEvent(new KeyboardEvent('keyup', { key: 'a' }));
+
+		expect(handleShortcut).not.toHaveBeenCalled();
+	});
 });

frontend/src/hooks/hotkeys/useKeyboardHotkeys.tsx

@@ -79,11 +79,11 @@ export function KeyboardHotkeysProvider({
 	const wasExtended = useRef(false);
 
 	const handleKeyDown = (event: KeyboardEvent): void => {
-		if (event.repeat) {
+		const { target } = event;
+		if (event.repeat || !(target instanceof Element)) {
 			return;
 		}
 
-		const target = event.target as HTMLElement;
 		const isCodeMirrorEditor = target.closest('.cm-editor') !== null;
 		const isMonacoEditor = target.closest('.monaco-editor') !== null;
 		if (