app.js

const express = require('express')
require('express-async-errors')
const app = express()
const cors = require('cors')
const mongoose = require('mongoose')
const config = require('./utils/config')
const blogsRouter = require('./controllers/blogs')
const usersRouter = require('./controllers/users')
const login = require('./controllers/login')

mongoose.set('useCreateIndex', true)

mongoose.connect(config.MONGODB_URI, { useNewUrlParser: true, useUnifiedTopology: true })

const tokenExtractor = (request, _response, next) => {
  const authorization = request.get('authorization')

  if (authorization && authorization.toLowerCase().startsWith('bearer ')) {
    request.token = authorization.substring(7)
  } else {
    request.token = null
  }

  next()
}

app.use(tokenExtractor)
app.use(cors())
app.use(express.json())
app.use('/api/blogs', blogsRouter)
app.use('/api/users', usersRouter)
app.use('/api/login', login)

if(process.env.NODE_ENV === 'test') {
  const testingRouter = require('./controllers/testing')
  app.use('/api/testing', testingRouter)
}

const errorHandler = (error, request, response, next) => {
  console.error(error.message)

  if(error.name === 'ValidationError'){
    return response.status(400).json({error: error.message})
  } else if (error.name === 'JsonWebTokenError') {
    return response.status(401).json({
      error: 'invalid token'
    })
  }

  next(error)
}
app.use(errorHandler)

module.exports = app