[perf] render head links before other content (#7160)

benmccann · web-flow · commit 0072df7a5cee · 2022-10-06T09:36:10.000+02:00
diff --git a/.changeset/four-crabs-beg.md b/.changeset/four-crabs-beg.md
@@ -0,0 +1,5 @@
+---
+'@sveltejs/kit': patch
+---
+
+[perf] render head links before other content
diff --git a/packages/kit/src/runtime/server/page/render.js b/packages/kit/src/runtime/server/page/render.js
@@ -135,7 +135,8 @@ export async function render_response({
 		rendered = { head: '', html: '', css: { code: '', map: null } };
 	}
 
-	let { head, html: body } = rendered;
+	let head = '';
+	let body = rendered.html;
 
 	const csp = new Csp(options.csp, {
 		dev: options.dev,
@@ -303,6 +304,9 @@ export async function render_response({
 		}
 	}
 
+	// add the content after the script/css links so the link elements are parsed first
+	head += rendered.head;
+
 	// TODO flush chunks as early as we can
 	const html =
 		(await resolve_opts.transformPageChunk({

-Original file line number
+Diff line change
@@ @@ -0,0 +1,5 @@ @@
 +---
 +'@sveltejs/kit': patch
 +---
++
 +[perf] render head links before other content
Original file line number	Diff line number	Diff line change
`@@ -135,7 +135,8 @@ export async function render_response({`
`135`	`135`	`rendered = { head: '', html: '', css: { code: '', map: null } };`
`136`	`136`	`}`
`137`	`137`
`138`		`- let { head, html: body } = rendered;`
	`138`	`+ let head = '';`
	`139`	`+ let body = rendered.html;`
`139`	`140`
`140`	`141`	`const csp = new Csp(options.csp, {`
`141`	`142`	`dev: options.dev,`
`@@ -303,6 +304,9 @@ export async function render_response({`
`303`	`304`	`}`
`304`	`305`	`}`
`305`	`306`
	`307`	`+ // add the content after the script/css links so the link elements are parsed first`
	`308`	`+ head += rendered.head;`
	`309`	`+`
`306`	`310`	`// TODO flush chunks as early as we can`
`307`	`311`	`const html =`
`308`	`312`	`(await resolve_opts.transformPageChunk({`