feat(nuxt): allow exposing type augmentations from extends layers (#7442)

packages/nuxt/src/core/nuxt.ts

@@ -57,6 +57,13 @@ async function initNuxt (nuxt: Nuxt) {
     // Add module augmentations directly to NuxtConfig
     opts.references.push({ path: resolve(nuxt.options.buildDir, 'types/schema.d.ts') })
     opts.references.push({ path: resolve(nuxt.options.buildDir, 'types/app.config.d.ts') })
+
+    for (const layer of nuxt.options._layers) {
+      const declaration = join(layer.cwd, 'index.d.ts')
+      if (fse.existsSync(declaration)) {
+        opts.references.push({ path: declaration })
+      }
+    }
   })
 
   // Add import protection

test/fixtures/basic/extends/bar/index.d.ts

@@ -0,0 +1,5 @@
+declare module 'bing' {
+  interface BingInterface {
+    foo: 'bar'
+  }
+}

test/fixtures/basic/types.ts

@@ -182,3 +182,9 @@ describe('app config', () => {
     expectTypeOf<AppConfig>().toMatchTypeOf<ExpectedMergedAppConfig>()
   })
 })
+
+describe('extends type declarations', () => {
+  it('correctly adds references to tsconfig', () => {
+    expectTypeOf<import('bing').BingInterface>().toEqualTypeOf<{ foo: 'bar' }>()
+  })
+})