Chore: Mobile: Improve note screen tests and fix CI warning (#11126)

packages/lib/testing/test-utils.ts

@@ -1092,6 +1092,34 @@ export const mockMobilePlatform = (platform: string) => {
 	};
 };
 
+// Waits for callback to not throw. Similar to react-native-testing-library's waitFor, but works better
+// with Joplin's mix of real and fake Jest timers.
+const realSetTimeout = setTimeout;
+export const waitFor = async (callback: ()=> Promise<void>) => {
+	const timeout = 10_000;
+	const startTime = performance.now();
+	let passed = false;
+	let lastError: Error|null = null;
+
+	while (!passed && performance.now() - startTime < timeout) {
+		try {
+			await callback();
+			passed = true;
+			lastError = null;
+		} catch (error) {
+			lastError = error;
+
+			await new Promise<void>(resolve => {
+				realSetTimeout(() => resolve(), 10);
+			});
+		}
+	}
+
+	if (lastError) {
+		throw lastError;
+	}
+};
+
 export const runWithFakeTimers = async (callback: ()=> Promise<void>) => {
 	if (typeof jest === 'undefined') {
 		throw new Error('Fake timers are only supported in jest.');