fix(@angular/build): avoid deploy URL usage on absolute preload links

clydin · alan-agius4 · commit a8ea9cf6ad3b · 2024-12-03T17:24:37.000+01:00
The `deployUrl` option was unintentionally being prepended to preload
links with absolute URLs within the generated index HTML for an appplication.
This has now been corrected and absolute URLs will not be altered when a
deploy URL is configured.
diff --git a/packages/angular/build/src/utils/index-file/augment-index-html.ts b/packages/angular/build/src/utils/index-file/augment-index-html.ts
@@ -65,17 +65,8 @@ export interface FileInfo {
 export async function augmentIndexHtml(
   params: AugmentIndexHtmlOptions,
 ): Promise<{ content: string; warnings: string[]; errors: string[] }> {
-  const {
-    loadOutputFile,
-    files,
-    entrypoints,
-    sri,
-    deployUrl = '',
-    lang,
-    baseHref,
-    html,
-    imageDomains,
-  } = params;
+  const { loadOutputFile, files, entrypoints, sri, deployUrl, lang, baseHref, html, imageDomains } =
+    params;
 
   const warnings: string[] = [];
   const errors: string[] = [];
@@ -117,7 +108,7 @@ export async function augmentIndexHtml(
 
   let scriptTags: string[] = [];
   for (const [src, isModule] of scripts) {
-    const attrs = [`src="${deployUrl}${src}"`];
+    const attrs = [`src="${generateUrl(src, deployUrl)}"`];
 
     // This is also need for non entry-points as they may contain problematic code.
     if (isModule) {
@@ -141,7 +132,7 @@ export async function augmentIndexHtml(
   let headerLinkTags: string[] = [];
   let bodyLinkTags: string[] = [];
   for (const src of stylesheets) {
-    const attrs = [`rel="stylesheet"`, `href="${deployUrl}${src}"`];
+    const attrs = [`rel="stylesheet"`, `href="${generateUrl(src, deployUrl)}"`];
 
     if (crossOrigin !== 'none') {
       attrs.push(`crossorigin="${crossOrigin}"`);
@@ -157,7 +148,7 @@ export async function augmentIndexHtml(
 
   if (params.hints?.length) {
     for (const hint of params.hints) {
-      const attrs = [`rel="${hint.mode}"`, `href="${deployUrl}${hint.url}"`];
+      const attrs = [`rel="${hint.mode}"`, `href="${generateUrl(hint.url, deployUrl)}"`];
 
       if (hint.mode !== 'modulepreload' && crossOrigin !== 'none') {
         // Value is considered anonymous by the browser when not present or empty
@@ -303,6 +294,19 @@ function generateSriAttributes(content: string): string {
   return `integrity="${algo}-${hash}"`;
 }
 
+function generateUrl(value: string, deployUrl: string | undefined): string {
+  if (!deployUrl) {
+    return value;
+  }
+
+  // Skip if root-relative, absolute or protocol relative url
+  if (/^((?:\w+:)?\/\/|data:|chrome:|\/)/.test(value)) {
+    return value;
+  }
+
+  return `${deployUrl}${value}`;
+}
+
 function updateAttribute(
   tag: { attrs: { name: string; value: string }[] },
   name: string,
diff --git a/packages/angular/build/src/utils/index-file/augment-index-html_spec.ts b/packages/angular/build/src/utils/index-file/augment-index-html_spec.ts
@@ -398,6 +398,46 @@ describe('augment-index-html', () => {
       `);
   });
 
+  it(`should not add deploy URL to hints with an absolute URL`, async () => {
+    const { content, warnings } = await augmentIndexHtml({
+      ...indexGeneratorOptions,
+      deployUrl: 'https://localhost/',
+      hints: [{ mode: 'preload', url: 'http://example.com/y?b=2' }],
+    });
+
+    expect(warnings).toHaveSize(0);
+    expect(content).toEqual(oneLineHtml`
+        <html>
+          <head>
+            <base href="/">
+            <link rel="preload" href="http://example.com/y?b=2">
+          </head>
+          <body>
+          </body>
+        </html>
+      `);
+  });
+
+  it(`should not add deploy URL to hints with a root-relative URL`, async () => {
+    const { content, warnings } = await augmentIndexHtml({
+      ...indexGeneratorOptions,
+      deployUrl: 'https://example.com/',
+      hints: [{ mode: 'preload', url: '/y?b=2' }],
+    });
+
+    expect(warnings).toHaveSize(0);
+    expect(content).toEqual(oneLineHtml`
+        <html>
+          <head>
+            <base href="/">
+            <link rel="preload" href="/y?b=2">
+          </head>
+          <body>
+          </body>
+        </html>
+      `);
+  });
+
   it('should add `.mjs` script tags', async () => {
     const { content } = await augmentIndexHtml({
       ...indexGeneratorOptions,
