add midlewares

app.js

@@ -3,6 +3,7 @@ const express = require('express')
 const app = express()
 const cors = require('cors')
 const BlogsRouter = require('./controllers/blogs')
+const middleware = require('./utils/middleware')
 const logger = require('./utils/logger')
 const mongoose = require('mongoose')
 mongoose.set('strictQuery', false)
@@ -19,8 +20,13 @@ mongoose
   })
 
 app.use(cors())
+app.use(express.static('build'))
 app.use(express.json())
+app.use(middleware.requestLogger)
 
 app.use('/api/blogs', BlogsRouter)
 
+app.use(middleware.unknownEndpoint)
+app.use(middleware.errorHandler)
+
 module.exports = app

utils/middleware.js

@@ -0,0 +1,31 @@
+const logger = require('./logger')
+
+const requestLogger = (request, response, next) => {
+  logger.info('Method:', request.method)
+  logger.info('Path:  ', request.path)
+  logger.info('Body:  ', request.body)
+  logger.info('---')
+  next()
+}
+
+const unknownEndpoint = (request, response) => {
+  response.status(404).send({ error: 'unknown endpoint' })
+}
+
+const errorHandler = (error, request, response, next) => {
+  logger.error(error.message)
+
+  if (error.name === 'CastError') {
+    return response.status(400).send({ error: 'malformatted id' })
+  } else if (error.name === 'ValidationError') {
+    return response.status(400).json({ error: error.message })
+  }
+
+  next(error)
+}
+
+module.exports = {
+  requestLogger,
+  unknownEndpoint,
+  errorHandler,
+}