feat: use loadNuxt (resolves #57)

BREAKING CHANGE: requires nuxt > 2.12

lib/plugin.js

@@ -1,13 +1,8 @@
-const { resolve } = require('path')
-const { existsSync } = require('fs')
-const esm = require('esm')
-
 exports.register = async function (server, _config) {
   // Apply defaults
   const config = {
     dev: process.env.NODE_ENV !== 'production',
     rootDir: process.cwd(),
-    nuxtConfig: 'nuxt.config.js',
     edge: false,
     baseURL: null,
     route: {},
@@ -16,26 +11,18 @@ exports.register = async function (server, _config) {
   }
 
   // Requre Nuxt
-  const { Nuxt, Builder } = require(config.edge ? 'nuxt-edge' : 'nuxt')
+  const { loadNuxt, getBuilder } = tryRequire('nuxt-edge') || tryRequire('nuxt')
 
-  // Resolve nuxt.config relative to rootDir
-  config.nuxtConfig = resolve(config.rootDir, config.nuxtConfig)
+  if (!loadNuxt) {
+    throw new Error('Ensure nuxt or nuxt-edge >= 2.12 is instaled')
+  }
 
-  // Load config
-  const requireESM = esm(module, {
-    cache: false
+  // Initialize nuxt
+  const nuxt = await loadNuxt({
+    rootDir: config.rootDir,
+    configOverrides: config.overrides,
+    for: config.dev ? 'dev' : 'start'
   })
-  const nuxtConfig = existsSync(config.nuxtConfig) ? requireESM(config.nuxtConfig) : {}
-
-  // Set rootDir and dev
-  nuxtConfig.rootDir = config.rootDir
-  nuxtConfig.dev = config.dev
-
-  // Create nuxt instance using options
-  const nuxt = new Nuxt(nuxtConfig)
-
-  // Await nuxt to be ready
-  await nuxt.ready()
 
   // Expose nuxt
   server.expose('nuxt', nuxt)
@@ -62,11 +49,18 @@ exports.register = async function (server, _config) {
 
   // Development mode
   if (config.dev) {
-    const builder = new Builder(nuxt)
+    const builder = await getBuilder(nuxt)
     server.expose('builder', builder)
     builder.build().catch(console.error)
   }
 }
 
+function tryRequire (pkg) {
+  try {
+    return require(pkg)
+  } catch (err) {
+  }
+}
+
 exports.name = 'nuxt'
 exports.pkg = require('../package.json')