feat: head.startElements support

crutch12 · crutch12 · commit fadcf2945a58 · 2025-12-09T19:22:02.000+03:00
diff --git a/src/plugins/prerender-plugin.js b/src/plugins/prerender-plugin.js
@@ -383,7 +383,7 @@ export function prerenderPlugin({ prerenderScript, renderTarget, additionalPrere
             };
 
             /** @type {import('./types.d.ts').Head} */
-            let head = { lang: '', title: '', elements: new Set() };
+            let head = { lang: '', title: '', elements: new Set(), startElements: new Set() };
 
             let prerender;
             try {
@@ -435,7 +435,7 @@ export function prerenderPlugin({ prerenderScript, renderTarget, additionalPrere
 
                 // Reset HTML doc & head data
                 const htmlDoc = htmlParse(tpl, { comment: true });
-                head = { lang: '', title: '', elements: new Set() };
+                head = { lang: '', title: '', elements: new Set(), startElements: new Set() };
 
                 // Add any discovered links to the list of routes to pre-render:
                 if (result.links) {
@@ -480,6 +480,16 @@ export function prerenderPlugin({ prerenderScript, renderTarget, additionalPrere
                         htmlDoc.querySelector('html').setAttribute('lang', enc(head.lang));
                     }
 
+                    if (head.startElements) {
+                        // Inject HTML links at the start of <head> for any stylesheets injected during rendering of the page:
+                        htmlHead.insertAdjacentHTML(
+                            'afterbegin',
+                            Array.from(
+                                new Set(Array.from(head.startElements).map(serializeElement)),
+                            ).join('\n'),
+                        );
+                    }
+
                     if (head.elements) {
                         // Inject HTML links at the end of <head> for any stylesheets injected during rendering of the page:
                         htmlHead.insertAdjacentHTML(
diff --git a/src/plugins/types.d.ts b/src/plugins/types.d.ts
@@ -7,6 +7,13 @@ export interface HeadElement {
 export interface Head {
     lang: string;
     title: string;
+    /**
+     * Which elements should be injected in the **start** of <head>
+     */
+    startElements: Set<HeadElement>;
+    /**
+     * Which elements should be injected in the **end** of <head>
+     */
     elements: Set<HeadElement>;
 }
 
diff --git a/tests/prerender-api.test.js b/tests/prerender-api.test.js
@@ -94,6 +94,29 @@ test('Should support `head.title` property', async () => {
     assert.match(prerenderedHtml, '<title>My Prerendered Site</title>');
 });
 
+test('Should support `head.startElements` property', async () => {
+    await loadFixture('simple', env);
+    await writeEntry(
+        env.tmp.path,
+        `
+        export async function prerender() {
+            return {
+                html: '<h1>Hello, World!</h1>',
+                head: {
+                    startElements: new Set([
+                        { type: 'link', props: { rel: 'stylesheet', href: 'foo.css' } },
+                    ]),
+                },
+            };
+        }
+    `,
+    );
+    await viteBuild(env.tmp.path);
+
+    const prerenderedHtml = await getOutputFile(env.tmp.path, 'index.html');
+    assert.match(prerenderedHtml, '<link rel="stylesheet" href="foo.css">');
+});
+
 test('Should support `head.elements` property', async () => {
     await loadFixture('simple', env);
     await writeEntry(env.tmp.path, `
