Add wait helper function for async detection

Implement the wait() async helper function that waits for a detection
to return true by repeatedly checking it on each animation frame. This
is useful for DOM-based detections that need to wait for elements to
appear before the document is fully loaded.

- Add wait() function that loops using requestAnimationFrame
- Add comprehensive tests for the wait function
- Update test infrastructure to support async detection functions
- Add JSDoc documentation with usage examples

Co-authored-by: fregante <1402241+fregante@users.noreply.github.com>

Author: Copilot

index.test.ts

@@ -5,8 +5,15 @@ import stripIndent from 'strip-indent';
 import {getAllUrls, getTests} from './collector.js';
 import * as pageDetect from './index.js';
 
-(globalThis as any).document = {title: ''};
+(globalThis as any).document = {title: '', readyState: 'loading'};
 (globalThis as any).location = new URL('https://github.com/');
+(globalThis as any).requestAnimationFrame = (callback: FrameRequestCallback) => setTimeout(() => {
+	callback(Date.now());
+}, 0) as unknown as number;
+
+(globalThis as any).cancelAnimationFrame = (id: number) => {
+	clearTimeout(id);
+};
 
 const allUrls = getAllUrls();
 
@@ -15,12 +22,20 @@ for (const [detectName, detect] of Object.entries(pageDetect)) {
 		continue;
 	}
 
+	// Skip wait and other utility functions
+	if (detectName === 'wait') {
+		continue;
+	}
+
 	const validURLs = getTests(detectName);
 
 	if (validURLs[0] === 'combinedTestOnly' || String(detect).startsWith('() =>')) {
 		continue;
 	}
 
+	// Type assertion for TypeScript to understand this is a detection function
+	const detectionFn = detect as (url?: URL | HTMLAnchorElement | Location) => boolean;
+
 	test(detectName + ' has tests', () => {
 		assert.ok(
 			Array.isArray(validURLs),
@@ -35,7 +50,7 @@ for (const [detectName, detect] of Object.entries(pageDetect)) {
 	for (const url of validURLs) {
 		test(`${detectName} ${url.replace('https://github.com', '')}`, () => {
 			assert.ok(
-				detect(new URL(url)),
+				detectionFn(new URL(url)),
 				stripIndent(`
 					Is this URL \`${detectName}\`?
 						${url.replace('https://github.com', '')}
@@ -56,7 +71,7 @@ for (const [detectName, detect] of Object.entries(pageDetect)) {
 		if (!validURLs.includes(url)) {
 			test(`${detectName} NO ${url}`, () => {
 				assert.equal(
-					detect(new URL(url)),
+					detectionFn(new URL(url)),
 					false,
 					stripIndent(`
 						Is this URL \`${detectName}\`?
@@ -281,3 +296,42 @@ test('parseRepoExplorerTitle', () => {
 		undefined,
 	);
 });
+
+test('wait - immediately true', async () => {
+	const detection = () => true;
+	const result = await pageDetect.wait(detection);
+	assert.equal(result, true);
+});
+
+test('wait - becomes true', async () => {
+	let callCount = 0;
+	const detection = () => {
+		callCount++;
+		return callCount >= 3;
+	};
+
+	const result = await pageDetect.wait(detection);
+	assert.equal(result, true);
+	assert.ok(callCount >= 3);
+});
+
+test('wait - false when document complete', async () => {
+	// Save original state
+	const originalReadyState = Object.getOwnPropertyDescriptor(document, 'readyState');
+
+	// Mock document.readyState to be 'complete'
+	Object.defineProperty(document, 'readyState', {
+		writable: true,
+		configurable: true,
+		value: 'complete',
+	});
+
+	const detection = () => false;
+	const result = await pageDetect.wait(detection);
+	assert.equal(result, false);
+
+	// Restore original state
+	if (originalReadyState) {
+		Object.defineProperty(document, 'readyState', originalReadyState);
+	}
+});

index.ts

@@ -4,6 +4,35 @@ import {addTests} from './collector.ts';
 const $ = <E extends Element>(selector: string) => document.querySelector<E>(selector);
 const exists = (selector: string) => Boolean($(selector));
 
+/**
+ * Waits for a detection to return true by repeatedly checking it on each animation frame.
+ * Useful for DOM-based detections that need to wait for elements to appear.
+ * @param detection - A detection function to check repeatedly
+ * @returns A promise that resolves to the final result of the detection
+ * @example
+ * ```
+ * import {wait, isOrganizationProfile} from 'github-url-detection';
+ *
+ * async function init() {
+ *   if (!await wait(isOrganizationProfile)) {
+ *     return;
+ *   }
+ *   // Do something when on organization profile
+ * }
+ * ```
+ */
+export async function wait(detection: () => boolean): Promise<boolean> {
+	// eslint-disable-next-line no-await-in-loop -- We need to wait on each frame
+	while (!detection() && document.readyState !== 'complete') {
+		// eslint-disable-next-line no-await-in-loop
+		await new Promise(resolve => {
+			requestAnimationFrame(resolve);
+		});
+	}
+
+	return detection();
+}
+
 const combinedTestOnly = ['combinedTestOnly']; // To be used only to skip tests of combined functions, i.e. isPageA() || isPageB()
 
 TEST: addTests('__urls_that_dont_match__', [