fix(cli): prevent both nuxt & nuxt-edge being installed (#6020)

packages/cli/src/run.js

@@ -1,10 +1,21 @@
 import fs from 'fs'
+import path from 'path'
 import execa from 'execa'
+import { name as pkgName } from '../package.json'
 import NuxtCommand from './command'
 import setup from './setup'
 import getCommand from './commands'
 
+function checkDuplicateNuxt() {
+  const dupPkg = pkgName === '@nuxt/cli' ? 'cli-edge' : 'cli'
+  if (fs.existsSync(path.resolve(__dirname, '..', '..', dupPkg))) {
+    throw new Error('Both `nuxt` and `nuxt-edge` are installed! This is unsupported, please choose one and remove the other one from dependencies.')
+  }
+}
+
 export default async function run(_argv) {
+  checkDuplicateNuxt()
+
   // Read from process.argv
   const argv = _argv ? Array.from(_argv) : process.argv.slice(2)
 

packages/cli/test/unit/run-edge.test.js

@@ -0,0 +1,12 @@
+import run from '../../src/run'
+
+jest.mock('../../package.json', () => ({
+  name: 'cli-edge'
+}))
+
+describe('run in edge', () => {
+  test('throws error if nuxt and nuxt-edge are installed', async () => {
+    await expect(run())
+      .rejects.toThrow('Both `nuxt` and `nuxt-edge` are installed! This is unsupported, please choose one and remove the other one from dependencies.')
+  })
+})