fix(prerender): ensure meta charset is first element in document.head

adamdbradley · adamdbradley · commit 590ddbf72156 · 2019-01-25T13:52:28.000-06:00
diff --git a/src/compiler/html/optimize-html.ts b/src/compiler/html/optimize-html.ts
@@ -6,6 +6,7 @@ import { inlineExternalAssets } from './inline-external-assets';
 import { inlineLoaderScript } from './inline-loader-script';
 import { minifyInlineScripts, minifyInlineStyles } from './minify-inline-content';
 import { optimizeSsrStyles } from '../style/optimize-ssr-styles';
+import { relocateMetaCharset } from './relocate-meta-charset';
 import { updateCanonicalLink } from './canonical-link';
 
 
@@ -98,6 +99,8 @@ export async function optimizeHtml(
     promises.push(assetVersioning(config, compilerCtx, hydrateTarget, windowLocationPath, doc));
   }
 
+  relocateMetaCharset(doc);
+
   await Promise.all(promises);
 }
 
diff --git a/src/compiler/html/relocate-meta-charset.ts b/src/compiler/html/relocate-meta-charset.ts
@@ -0,0 +1,21 @@
+
+
+export function relocateMetaCharset(doc: Document) {
+  if (!doc || !doc.head) {
+    return;
+  }
+
+  let charsetElm = doc.head.querySelector('meta[charset]');
+  if (charsetElm == null) {
+    // doesn't have <meta charset>, so create it
+    charsetElm = doc.createElement('meta');
+    charsetElm.setAttribute('charset', 'utf-8');
+
+  } else {
+    // take the current one out of its existing location
+    charsetElm.remove();
+  }
+
+  // ensure the <meta charset> is the first node in <head>
+  doc.head.insertBefore(charsetElm, doc.head.firstChild);
+}

Original file line number	Diff line number	Diff line change
`@@ -6,6 +6,7 @@ import { inlineExternalAssets } from './inline-external-assets';`
`6`	`6`	`import { inlineLoaderScript } from './inline-loader-script';`
`7`	`7`	`import { minifyInlineScripts, minifyInlineStyles } from './minify-inline-content';`
`8`	`8`	`import { optimizeSsrStyles } from '../style/optimize-ssr-styles';`
	`9`	`+import { relocateMetaCharset } from './relocate-meta-charset';`
`9`	`10`	`import { updateCanonicalLink } from './canonical-link';`
`10`	`11`
`11`	`12`
`@@ -98,6 +99,8 @@ export async function optimizeHtml(`
`98`	`99`	`promises.push(assetVersioning(config, compilerCtx, hydrateTarget, windowLocationPath, doc));`
`99`	`100`	`}`
`100`	`101`
	`102`	`+ relocateMetaCharset(doc);`
	`103`	`+`
`101`	`104`	`await Promise.all(promises);`
`102`	`105`	`}`
`103`	`106`