fix(schema): cleanup meta tags and deduplicate charset and viewport (#6378)

packages/nuxt/src/head/module.ts

@@ -1,17 +1,11 @@
 import { resolve } from 'pathe'
 import { addPlugin, addTemplate, defineNuxtModule } from '@nuxt/kit'
-import defu from 'defu'
 import { distDir } from '../dirs'
-import type { MetaObject } from './runtime'
 
 export default defineNuxtModule({
   meta: {
     name: 'meta'
   },
-  defaults: {
-    charset: 'utf-8',
-    viewport: 'width=device-width, initial-scale=1'
-  },
   setup (options, nuxt) {
     const runtimeDir = nuxt.options.alias['#head'] || resolve(distDir, 'head/runtime')
 
@@ -21,17 +15,10 @@ export default defineNuxtModule({
     // Add #head alias
     nuxt.options.alias['#head'] = runtimeDir
 
-    // Global meta -for Bridge, this is necessary to repeat here
-    // and in packages/schema/src/config/_app.ts
-    const globalMeta: MetaObject = defu(nuxt.options.app.head, {
-      charset: options.charset,
-      viewport: options.viewport
-    })
-
     // Add global meta configuration
     addTemplate({
       filename: 'meta.config.mjs',
-      getContents: () => 'export default ' + JSON.stringify({ globalMeta })
+      getContents: () => 'export default ' + JSON.stringify({ globalMeta: nuxt.options.app.head })
     })
 
     // Add generic plugin

packages/schema/src/config/_app.ts

@@ -105,15 +105,23 @@ export default {
      */
     head: {
       $resolve: (val, get) => {
-        return defu(val, get('meta'), {
-          charset: 'utf-8',
-          viewport: 'width=device-width, initial-scale=1',
+        const resolved = defu(val, get('meta'), {
           meta: [],
           link: [],
           style: [],
           script: [],
           noscript: []
         })
+
+        resolved.charset = resolved.charset ?? resolved.meta.find(m => m.charset)?.charset ?? 'utf-8'
+        resolved.viewport = resolved.viewport ?? resolved.meta.find(m => m.name === 'viewport')?.content ?? 'width=device-width, initial-scale=1'
+        resolved.meta = resolved.meta.filter(m => m && m.name !== 'viewport' && !m.charset)
+        resolved.link = resolved.link.filter(Boolean)
+        resolved.style = resolved.style.filter(Boolean)
+        resolved.script = resolved.script.filter(Boolean)
+        resolved.noscript = resolved.noscript.filter(Boolean)
+
+        return resolved
       }
     },
   },

test/basic.test.ts

@@ -138,6 +138,9 @@ describe('head tags', () => {
     expect(headHtml).toContain('<title>Using a dynamic component - Title Template Fn Change</title>')
     expect(headHtml).not.toContain('<meta name="description" content="first">')
     expect(headHtml).toContain('<meta charset="utf-16">')
+    expect(headHtml.match('meta charset').length).toEqual(1)
+    expect(headHtml).toContain('<meta name="viewport" content="width=1024, initial-scale=1">')
+    expect(headHtml.match('meta name="viewport"').length).toEqual(1)
     expect(headHtml).not.toContain('<meta charset="utf-8">')
     expect(headHtml).toContain('<meta name="description" content="overriding with an inline useHead call">')
     expect(headHtml).toMatch(/<html[^>]*class="html-attrs-test"/)

test/fixtures/basic/nuxt.config.ts

@@ -2,6 +2,13 @@ import { defineNuxtConfig } from 'nuxt'
 import { addComponent } from '@nuxt/kit'
 
 export default defineNuxtConfig({
+  app: {
+    head: {
+      charset: 'utf-8',
+      link: [undefined],
+      meta: [{ name: 'viewport', content: 'width=1024, initial-scale=1' }, { charset: 'utf-8' }]
+    }
+  },
   buildDir: process.env.NITRO_BUILD_DIR,
   builder: process.env.TEST_WITH_WEBPACK ? 'webpack' : 'vite',
   extends: [