feat(kit): load /module or /nuxt module subpath if it exists (#24707)

packages/kit/src/module/install.ts

@@ -61,18 +61,28 @@ export async function loadNuxtModuleInstance (nuxtModule: string | NuxtModule, n
   let buildTimeModuleMeta: ModuleMeta = {}
   // Import if input is string
   if (typeof nuxtModule === 'string') {
-    const src = await resolvePath(nuxtModule)
-    try {
+    const paths = [join(nuxtModule, 'nuxt'), join(nuxtModule, 'module'), nuxtModule]
+    let error: unknown
+    for (const path of paths) {
+      const src = await resolvePath(path)
       // Prefer ESM resolution if possible
+      try {
         nuxtModule = await importModule(src, nuxt.options.modulesDir).catch(() => null) ?? requireModule(src, { paths: nuxt.options.modulesDir })
-    } catch (error: unknown) {
-      logger.error(`Error while requiring module \`${nuxtModule}\`: ${error}`)
-      throw error
-    }
+
         // nuxt-module-builder generates a module.json with metadata including the version
         if (existsSync(join(dirname(src), 'module.json'))) {
           buildTimeModuleMeta = JSON.parse(await fsp.readFile(join(dirname(src), 'module.json'), 'utf-8'))
         }
+        break
+      } catch (_err: unknown) {
+        error = _err
+        continue
+      }
+    }
+    if (!nuxtModule && error) {
+      logger.error(`Error while requiring module \`${nuxtModule}\`: ${error}`)
+      throw error
+    }
   }
 
   // Throw error if input is not a function

test/fixtures/basic/modules/subpath/index.ts

@@ -0,0 +1 @@
+export const someUtil = () => {}

test/fixtures/basic/modules/subpath/module.ts

@@ -0,0 +1,5 @@
+import { defineNuxtModule } from 'nuxt/kit'
+
+export default defineNuxtModule({
+  meta: { name: 'subpath' },
+})

test/fixtures/basic/nuxt.config.ts

@@ -80,6 +80,7 @@ export default defineNuxtConfig({
     }
   },
   modules: [
+    '~/modules/subpath',
     './modules/test',
     '~/modules/example',
     function (_, nuxt) {