feat(kit): add addLayout (#5537)

packages/kit/src/index.ts

@@ -14,6 +14,7 @@ export * from './compatibility'
 export * from './components'
 export * from './context'
 export * from './ignore'
+export * from './layout'
 export * from './pages'
 export * from './plugin'
 export * from './resolve'

packages/kit/src/layout.ts

@@ -0,0 +1,42 @@
+import type { NuxtTemplate } from '@nuxt/schema'
+import { join, parse, relative } from 'pathe'
+import { kebabCase } from 'scule'
+import { isNuxt2 } from './compatibility'
+import { useNuxt } from './context'
+import { logger } from './logger'
+import { addTemplate } from './template'
+
+export function addLayout (tmpl: NuxtTemplate, name?: string) {
+  const nuxt = useNuxt()
+  const { filename, src } = addTemplate(tmpl)
+  const layoutName = kebabCase(name || parse(tmpl.filename).name).replace(/["']/g, '')
+
+  if (isNuxt2(nuxt)) {
+    // Nuxt 2 adds layouts in options
+    const layout = nuxt.options.layouts[layoutName]
+    if (layout) {
+      return logger.warn(
+        `Not overriding \`${layoutName}\` (provided by \`${layout}\`) with \`${src || filename}\`.`
+      )
+    }
+    nuxt.options.layouts[layoutName] = `./${filename}`
+    if (name === 'error') {
+      this.addErrorLayout(filename)
+    }
+    return
+  }
+
+  // Nuxt 3 adds layouts on app
+  nuxt.hook('app:templates', (app) => {
+    if (layoutName in app.layouts) {
+      const relativePath = relative(nuxt.options.srcDir, app.layouts[layoutName].file)
+      return logger.warn(
+        `Not overriding \`${layoutName}\` (provided by \`~/${relativePath}\`) with \`${src || filename}\`.`
+      )
+    }
+    app.layouts[layoutName] = {
+      file: join('#build', filename),
+      name: layoutName
+    }
+  })
+}

packages/kit/src/module/container.ts

@@ -1,8 +1,8 @@
-import { parse, relative } from 'pathe'
+import { relative } from 'pathe'
 import type { Nuxt, NuxtPluginTemplate, NuxtTemplate, ModuleContainer } from '@nuxt/schema'
-import { logger } from '../logger'
 import { chainFn } from '../internal/task'
 import { addTemplate } from '../template'
+import { addLayout } from '../layout'
 import { addServerMiddleware } from '../server'
 import { isNuxt2 } from '../compatibility'
 import { addPluginTemplate } from '../plugin'
@@ -61,18 +61,8 @@ export function useModuleContainer (nuxt: Nuxt = useNuxt()): ModuleContainer {
       return addPluginTemplate(pluginTemplate)
     },
 
-    addLayout (tmpl: NuxtTemplate, name: string) {
-      const { filename, src } = addTemplate(tmpl)
-      const layoutName = name || parse(src).name
-      const layout = nuxt.options.layouts[layoutName]
-
-      if (layout) {
-        logger.warn(`Duplicate layout registration, "${layoutName}" has been registered as "${layout}"`)
-      }
-      nuxt.options.layouts[layoutName] = `./${filename}`
-      if (name === 'error') {
-        this.addErrorLayout(filename)
-      }
+    addLayout (tmpl: NuxtTemplate, name?: string) {
+      return addLayout(tmpl, name)
     },
 
     addErrorLayout (dst: string) {