feat(kit,nuxt): add component priority to allow overriding (#19252)

packages/kit/src/components.ts

@@ -40,14 +40,24 @@ export async function addComponent (opts: AddComponentOptions) {
     preload: false,
     mode: 'all',
     shortPath: opts.filePath,
+    priority: 0,
     ...opts
   }
 
   nuxt.hook('components:extend', (components: Component[]) => {
     const existingComponent = components.find(c => (c.pascalName === component.pascalName || c.kebabName === component.kebabName) && c.mode === component.mode)
     if (existingComponent) {
-      const name = existingComponent.pascalName || existingComponent.kebabName
-      console.warn(`Overriding ${name} component.`)
+      const existingPriority = existingComponent.priority ?? 0
+      const newPriority = component.priority ?? 0
+
+      if (newPriority < existingPriority) { return }
+
+      // We override where new component priority is equal or higher
+      // but we warn if they are equal.
+      if (newPriority === existingPriority) {
+        const name = existingComponent.pascalName || existingComponent.kebabName
+        console.warn(`Overriding ${name} component. You can specify a \`priority\` option when calling \`addComponent\` to avoid this warning.`)
+      }
       Object.assign(existingComponent, component)
     } else {
       components.push(component)

packages/nuxt/src/components/scan.ts

@@ -118,7 +118,9 @@ export async function scanComponents (dirs: ComponentsDir[], srcDir: string): Pr
         kebabName,
         chunkName,
         shortPath,
-        export: 'default'
+        export: 'default',
+        // by default, give priority to scanned components
+        priority: 1
       }
 
       if (typeof dir.extendComponent === 'function') {

packages/nuxt/src/core/nuxt.ts

@@ -158,47 +158,55 @@ async function initNuxt (nuxt: Nuxt) {
   // Add <NuxtWelcome>
   addComponent({
     name: 'NuxtWelcome',
+    priority: 10, // built-in that we do not expect the user to override
     filePath: tryResolveModule('@nuxt/ui-templates/templates/welcome.vue')!
   })
 
   addComponent({
     name: 'NuxtLayout',
+    priority: 10, // built-in that we do not expect the user to override
     filePath: resolve(nuxt.options.appDir, 'components/layout')
   })
 
   // Add <NuxtErrorBoundary>
   addComponent({
     name: 'NuxtErrorBoundary',
+    priority: 10, // built-in that we do not expect the user to override
     filePath: resolve(nuxt.options.appDir, 'components/nuxt-error-boundary')
   })
 
   // Add <ClientOnly>
   addComponent({
     name: 'ClientOnly',
+    priority: 10, // built-in that we do not expect the user to override
     filePath: resolve(nuxt.options.appDir, 'components/client-only')
   })
 
   // Add <DevOnly>
   addComponent({
     name: 'DevOnly',
+    priority: 10, // built-in that we do not expect the user to override
     filePath: resolve(nuxt.options.appDir, 'components/dev-only')
   })
 
   // Add <ServerPlaceholder>
   addComponent({
     name: 'ServerPlaceholder',
+    priority: 10, // built-in that we do not expect the user to override
     filePath: resolve(nuxt.options.appDir, 'components/server-placeholder')
   })
 
   // Add <NuxtLink>
   addComponent({
     name: 'NuxtLink',
+    priority: 10, // built-in that we do not expect the user to override
     filePath: resolve(nuxt.options.appDir, 'components/nuxt-link')
   })
 
   // Add <NuxtLoadingIndicator>
   addComponent({
     name: 'NuxtLoadingIndicator',
+    priority: 10, // built-in that we do not expect the user to override
     filePath: resolve(nuxt.options.appDir, 'components/nuxt-loading-indicator')
   })
 
@@ -206,6 +214,7 @@ async function initNuxt (nuxt: Nuxt) {
   if (nuxt.options.experimental.componentIslands) {
     addComponent({
       name: 'NuxtIsland',
+      priority: 10, // built-in that we do not expect the user to override
       filePath: resolve(nuxt.options.appDir, 'components/nuxt-island')
     })
   }

packages/nuxt/src/head/module.ts

@@ -24,6 +24,8 @@ export default defineNuxtModule({
         name: componentName,
         filePath: componentsPath,
         export: componentName,
+        // built-in that we do not expect the user to override
+        priority: 10,
         // kebab case version of these tags is not valid
         kebabName: componentName
       })

packages/nuxt/src/pages/module.ts

@@ -43,6 +43,7 @@ export default defineNuxtModule({
       })
       addComponent({
         name: 'NuxtPage',
+        priority: 10, // built-in that we do not expect the user to override
         filePath: resolve(distDir, 'pages/runtime/page-placeholder')
       })
       return
@@ -256,6 +257,7 @@ export default defineNuxtModule({
     // Add <NuxtPage>
     addComponent({
       name: 'NuxtPage',
+      priority: 10, // built-in that we do not expect the user to override
       filePath: resolve(distDir, 'pages/runtime/page')
     })
 

packages/nuxt/test/scan-components.test.ts

@@ -97,6 +97,7 @@ const expectedComponents = [
     pascalName: 'Isle',
     prefetch: false,
     preload: false,
+    priority: 1,
     shortPath: 'components/islands/Isle.vue'
   },
   {
@@ -109,6 +110,7 @@ const expectedComponents = [
     pascalName: 'Glob',
     prefetch: false,
     preload: false,
+    priority: 1,
     shortPath: 'components/global/Glob.vue'
   },
   {
@@ -121,7 +123,8 @@ const expectedComponents = [
     global: undefined,
     island: undefined,
     prefetch: false,
-    preload: false
+    preload: false,
+    priority: 1
   },
   {
     mode: 'client',
@@ -133,7 +136,8 @@ const expectedComponents = [
     global: undefined,
     island: undefined,
     prefetch: false,
-    preload: false
+    preload: false,
+    priority: 1
   },
   {
     mode: 'server',
@@ -145,7 +149,8 @@ const expectedComponents = [
     global: undefined,
     island: undefined,
     prefetch: false,
-    preload: false
+    preload: false,
+    priority: 1
   },
   {
     chunkName: 'components/client-component-with-props',
@@ -157,6 +162,7 @@ const expectedComponents = [
     pascalName: 'ClientComponentWithProps',
     prefetch: false,
     preload: false,
+    priority: 1,
     shortPath: 'components/client/ComponentWithProps.vue'
   },
   {
@@ -169,6 +175,7 @@ const expectedComponents = [
     pascalName: 'ClientWithClientOnlySetup',
     prefetch: false,
     preload: false,
+    priority: 1,
     shortPath: 'components/client/WithClientOnlySetup.vue'
   },
   {
@@ -181,7 +188,8 @@ const expectedComponents = [
     global: undefined,
     island: undefined,
     prefetch: false,
-    preload: false
+    preload: false,
+    priority: 1
   },
   {
     chunkName: 'components/some-glob',
@@ -193,6 +201,7 @@ const expectedComponents = [
     pascalName: 'SomeGlob',
     prefetch: false,
     preload: false,
+    priority: 1,
     shortPath: 'components/some-glob.global.vue'
   },
   {
@@ -205,6 +214,7 @@ const expectedComponents = [
     pascalName: 'Some',
     prefetch: false,
     preload: false,
+    priority: 1,
     shortPath: 'components/some.island.vue'
   }
 ]

packages/schema/src/types/components.ts

@@ -10,6 +10,12 @@ export interface Component {
   global?: boolean
   island?: boolean
   mode?: 'client' | 'server' | 'all'
+  /**
+   * This number allows configuring the behavior of overriding Nuxt components.
+   * If multiple components are provided with the same name, then higher priority
+   * components will be used instead of lower priority components.
+   */
+  priority?: number
 }
 
 export interface ScanDir {