Выпадает ошибка Cannot find module 'HelloWorld'?

{
  "name": "vue_node",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "start": "node index.js"
  },
  "author": "",
  "license": "ISC",
  "dependencies": {
    "express": "^4.16.2",
    "express-vue": "^4.0.13",
    "sqlite3": "^3.1.13",
    "vue": "^2.3.4"
  }
}

const express = require('express');
const expressVue = require('express-vue');
const path = require('path');

const app = express();

app.use(expressVue.init({
  rootPath: path.join(__dirname, 'app')
}));

app.set('view engine', 'vue');

app.set('views', path.join(__dirname, 'app'));

app.set('vue', {
  componentsDir: path.join(__dirname, 'app/components')
});

app.use(express.static(path.join(__dirname, 'assets')))

app.get('/', (req, res) => {
  res.renderVue('App');
});


app.listen(3000, () => {
  console.log('Server started on port 3000')
});

<template>
  <div id="app">
    <HelloWorld />
  </div>
</template>

<script>
import HelloWorld from 'HelloWorld'

export default {
  name: 'app',
  components: {
    HelloWorld
  }
}
</script>

<style>
</style>

<template>
  <div>
    <h1>Hello World</h1>
  </div>
</template>

<script>
export default {
  name: 'HelloWorld'
}
</script>

<style>
</style>