From a5201854429f2487a0733e4553c6b9f628f54e26 Mon Sep 17 00:00:00 2001
From: Daniel Roe <daniel@roe.dev>
Date: Tue, 30 Aug 2022 15:41:11 +0100
Subject: [PATCH] perf(nuxt): don't prefetch all global components (#7069)

---
 packages/nuxt/src/components/module.ts | 12 ++++++++++++
 test/basic.test.ts                     |  7 +++++++
 2 files changed, 19 insertions(+)

diff --git a/packages/nuxt/src/components/module.ts b/packages/nuxt/src/components/module.ts
index 5656b4dae4..4f71dc19b2 100644
--- a/packages/nuxt/src/components/module.ts
+++ b/packages/nuxt/src/components/module.ts
@@ -130,6 +130,18 @@ export default defineNuxtModule<ComponentsOptions>({
       }
     })
 
+    // Do not prefetch global components chunks
+    nuxt.hook('build:manifest', (manifest) => {
+      const sourceFiles = getComponents().filter(c => c.global).map(c => relative(nuxt.options.srcDir, c.filePath))
+
+      for (const key in manifest) {
+        if (manifest[key].isEntry) {
+          manifest[key].dynamicImports =
+            manifest[key].dynamicImports?.filter(i => !sourceFiles.includes(i))
+        }
+      }
+    })
+
     // Scan components and add to plugin
     nuxt.hook('app:templates', async () => {
       const newComponents = await scanComponents(componentDirs, nuxt.options.srcDir!)
diff --git a/test/basic.test.ts b/test/basic.test.ts
index f41310a14a..893f40ef7c 100644
--- a/test/basic.test.ts
+++ b/test/basic.test.ts
@@ -380,6 +380,13 @@ describe('prefetching', () => {
   it('should prefetch components', async () => {
     await expectNoClientErrors('/prefetch/components')
   })
+  it('should not prefetch certain dynamic imports by default', async () => {
+    const html = await $fetch('/auth')
+    // should not prefetch global components
+    expect(html).not.toMatch(/<link [^>]*\/_nuxt\/TestGlobal[^>]*\.js"/)
+    // should not prefetch all other pages
+    expect(html).not.toMatch(/<link [^>]*\/_nuxt\/navigate-to[^>]*\.js"/)
+  })
 })
 
 if (process.env.NUXT_TEST_DEV) {