test(docs-infra): unregister the SW after each test (#28290)

This ensures that the SW is cleaned up, even in cases where
synchronization is disabled (and thus the clean-up inside `goTo()`
happens without waiting for Angular).

PR Close #28290

aio/tests/deployment/e2e/redirection.e2e-spec.ts

@@ -10,7 +10,11 @@ describe(browser.baseUrl, () => {
   beforeAll(() => page.init());
 
   beforeEach(() => browser.waitForAngularEnabled(false));
-  afterEach(() => browser.waitForAngularEnabled(true));
+
+  afterEach(async () => {
+    await page.unregisterSw();
+    await browser.waitForAngularEnabled(true);
+  });
 
   describe('(with sitemap URLs)', () => {
     page.sitemapUrls.forEach((path, i) => {

aio/tests/deployment/e2e/site.po.ts

@@ -42,15 +42,10 @@ export class SitePage {
    * (The SW is unregistered to ensure that subsequent requests are passed through to the server.)
    */
   async goTo(url: string) {
-    const unregisterServiceWorker = (cb: () => void) => navigator.serviceWorker
-        .getRegistrations()
-        .then(regs => Promise.all(regs.map(reg => reg.unregister())))
-        .then(cb);
-
     await browser.get(url || this.baseUrl);
     await browser.executeScript('document.body.classList.add(\'no-animations\')');
     await browser.waitForAngular();
-    await browser.executeAsyncScript(unregisterServiceWorker);
+    await this.unregisterSw();
   };
 
   /**
@@ -60,4 +55,16 @@ export class SitePage {
     // Make an initial request to unregister the ServiceWorker.
     await this.goTo('');
   }
+
+  /**
+   * Unregister the ServiceWorker (if registered).
+   */
+  async unregisterSw() {
+    const unregisterSwFn = (cb: () => void) => navigator.serviceWorker
+        .getRegistrations()
+        .then(regs => Promise.all(regs.map(reg => reg.unregister())))
+        .then(cb);
+
+    await browser.executeAsyncScript(unregisterSwFn);
+  }
 }

aio/tests/deployment/e2e/smoke-tests.e2e-spec.ts

@@ -7,7 +7,11 @@ describe(browser.baseUrl, () => {
   beforeAll(() => page.init());
 
   beforeEach(() => browser.waitForAngularEnabled(false));
-  afterEach(() => browser.waitForAngularEnabled(true));
+
+  afterEach(async () => {
+    await page.unregisterSw();
+    await browser.waitForAngularEnabled(true);
+  });
 
   describe('(smoke tests)', () => {
     it('should show the home page', () => {