@ngx-playwright/test/harness/change-detection.js

import {waitUntilAngularStable} from "./browser.js";

let isRegistered = false;
let disabledCount = 0;

/**
 * Returns whether the stabilize function should be executed automatically
 *
 * This takes into account whether automatic stabilization is turned on (see
 * {@link isAutoStabilizing}) and whether batch-mode is currently enabled.
 *
 * @returns {boolean}
 */
export function shouldStabilizeAutomatically() {
	return isRegistered && disabledCount === 0;
}

/**
 * Returns whether automatic stabilization is turned on
 *
 * Note this function doesn't take into account whether batch mode is enabled,
 * use {@link shouldStabilizeAutomatically} for that.
 *
 * @returns {boolean}
 */
export function isAutoStabilizing() {
	return isRegistered;
}

/** @type {Set<import('@playwright/test').Page>} */
const pages = new Set();

/**
 * Register the given page for automatic stabilization
 *
 * Automatic stabilization will wait for all registered pages to become stable before continuing.
 *
 * @param {import('@playwright/test').Page} page The page to register
 * @returns {void}
 */
export function registerPage(page) {
	if (pages.has(page)) {
		// already registered
		return;
	}

	pages.add(page);
	page.on("close", () => pages.delete(page));
}

/**
 * Automatically wait for the angular application to be come stable
 *
 * Calling this function makes all elements created in all environments
 * automatically wait. Waiting is done before anything is read from the page,
 * and after anything is done to the page.
 *
 * The environment automatically waits for stabilization by default, unless
 * {@link #manuallyStabilize} is called.
 *
 * @param {import('@angular/cdk/testing')['handleAutoChangeDetectionStatus']} handleAutoChangeDetectionStatus
 */
export function autoStabilize(handleAutoChangeDetectionStatus) {
	if (isRegistered) {
		return;
	}

	isRegistered = true;
	handleAutoChangeDetectionStatus((status) => {
		if (status.isDisabled) {
			if (disabledCount++) {
				status.onDetectChangesNow?.();
				return;
			}
		} else {
			if ((disabledCount = Math.max(0, disabledCount - 1))) {
				status.onDetectChangesNow?.();
				return;
			}
		}

		if (status.onDetectChangesNow) {
			Promise.all(
				Array.from(pages, (page) => page.evaluate(waitUntilAngularStable)),
			).then(
				() => status.onDetectChangesNow?.(),
				() => status.onDetectChangesNow?.(),
			);
		}
	});
}

/**
 * Stop automatically waiting for the angular application to become stable
 *
 * Call {@link #forceStabilize} to manually wait until the app stabilizes.
 *
 * @param {import('@angular/cdk/testing')['stopHandlingAutoChangeDetectionStatus']=} stopHandlingAutoChangeDetectionStatus
 */
export function manuallyStabilize(stopHandlingAutoChangeDetectionStatus) {
	if (!isRegistered) {
		return;
	}

	isRegistered = false;
	stopHandlingAutoChangeDetectionStatus?.();
}