fix(@angular-devkit/build-angular): baseHref with protocol and localize option

`posix.join` will dedupe double forward slashes resulting in incorrect protocol.

Closes: #17029
(cherry picked from commit 4e65705)

Author: alan-agius4

packages/angular_devkit/build_angular/src/browser/index.ts

@@ -49,6 +49,7 @@ import {
   normalizeAssetPatterns,
   normalizeOptimization,
   normalizeSourceMaps,
+  urlJoin,
 } from '../utils';
 import { BundleActionExecutor } from '../utils/action-executor';
 import { findCachePath } from '../utils/cache-path';
@@ -695,11 +696,9 @@ export function buildWebpackBrowser(
               for (const [locale, outputPath] of outputPaths.entries()) {
                 let localeBaseHref;
                 if (i18n.locales[locale] && i18n.locales[locale].baseHref !== '') {
-                  localeBaseHref = path.posix.join(
+                  localeBaseHref = urlJoin(
                     options.baseHref || '',
-                    i18n.locales[locale].baseHref === undefined
-                      ? `/${locale}/`
-                      : i18n.locales[locale].baseHref,
+                    i18n.locales[locale].baseHref ?? `/${locale}/`,
                   );
                 }
 
@@ -726,11 +725,9 @@ export function buildWebpackBrowser(
               for (const [locale, outputPath] of outputPaths.entries()) {
                 let localeBaseHref;
                 if (i18n.locales[locale] && i18n.locales[locale].baseHref !== '') {
-                  localeBaseHref = path.posix.join(
+                  localeBaseHref = urlJoin(
                     options.baseHref || '',
-                    i18n.locales[locale].baseHref === undefined
-                      ? `/${locale}/`
-                      : i18n.locales[locale].baseHref,
+                    i18n.locales[locale].baseHref ?? `/${locale}/`,
                   );
                 }
 

packages/angular_devkit/build_angular/src/utils/index.ts

@@ -15,3 +15,4 @@ export * from './normalize-asset-patterns';
 export * from './normalize-source-maps';
 export * from './normalize-optimization';
 export * from './normalize-builder-schema';
+export * from './url';

packages/angular_devkit/build_angular/src/utils/url.ts

@@ -0,0 +1,17 @@
+/**
+ * @license
+ * Copyright Google Inc. All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+
+
+export function urlJoin(...parts: string[]): string {
+  const [p, ...rest] = parts;
+
+  // Remove trailing slash from first part
+  // Join all parts with `/`
+  // Dedupe double slashes from path names
+  return p.replace(/\/$/, '') + ('/' + rest.join('/')).replace(/\/\/+/g, '/');
+}

packages/angular_devkit/build_angular/src/utils/url_spec.ts

@@ -0,0 +1,30 @@
+/**
+ * @license
+ * Copyright Google Inc. All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+import { urlJoin } from './url';
+
+describe('urlJoin', () => {
+  it('should work with absolute url with trailing slash', () => {
+    expect(urlJoin('http://foo.com/', '/one/')).toBe('http://foo.com/one/');
+  });
+
+  it('should work with absolute url without trailing slash', () => {
+    expect(urlJoin('http://foo.com', '/one')).toBe('http://foo.com/one');
+  });
+
+  it('should work with absolute url without slashes', () => {
+    expect(urlJoin('http://foo.com', 'one', 'two')).toBe('http://foo.com/one/two');
+  });
+
+  it('should work with relative url without slashes', () => {
+    expect(urlJoin('one', 'two', 'three')).toBe('one/two/three');
+  });
+
+  it('should keep trailing slash if empty path is provided', () => {
+    expect(urlJoin('one/', '')).toBe('one/');
+  });
+});

tests/legacy-cli/e2e/tests/i18n/ivy-localize-basehref.ts

@@ -100,4 +100,11 @@ export default async function() {
       server.close();
     }
   }
+
+  // Test absolute base href.
+  await ng('build', '--base-href', 'http://www.domain.com/');
+  for (const { lang, outputPath } of langTranslations) {
+    // Verify the HTML base HREF attribute is present
+    await expectFileToMatch(`${outputPath}/index.html`, `href="http://www.domain.com${baseHrefs[lang] || '/'}"`);
+  }
 }