node.js training

forward.js

const http = require('http')

const baseUrl = 'httpbin.org'

http.createServer((request, response) => {
  const forward = http.request({
    host: baseUrl,
    path: request.url,
    method: request.method,
    headers: request.headers
  }, (fresponse) => {
    fresponse.pipe(response)
  })

  request.pipe(forward)
}).listen(3000)

static.js

const http = require('http')
const fs = require('fs')
const url = require('url')
const path = require('path')
const mime = require('mime')
const got = require('got')
const assert = require('assert').strict

const root = __dirname

http.createServer((request, response) => {
  const uri = url.parse(request.url).pathname
  const file = path.join(root, uri)

  fs.stat(file, (err, stat) => {
    if (err || !stat.isFile()) {
      response.writeHead(404, {
        'Content-Type': 'text/plain'
      })
      response.write('NOT_FOUND')
      response.end()
      return
    }

    const stream = fs.createReadableStream(file)
    
    stream.on('open', () => {
      response.writeHead(200, {
        'Content-Type': mime.getType(path.extname(file)) || 'application/octet',
        'Content-Length': stat.size
      })
      stream.pipe(response)
    })

    stream.on('error', () => {
      response.writeHead(500, {
        'Content-Type': 'text/plain'
      })
      response.write('SERVER_ERROR')
      response.end()
    })

  })

}).listen(8080)

async function test() {
  const cases = [
    {
      url: 'http://localhost:8080/mime/img.png',
      status: 200,
      type: 'image/png'
    },
    {
      url: 'http://localhost:8080/mime/cli.js',
      status: 200,
      type: 'application/javascript'
    },
    {
      url: 'http://localhost:8080/naa',
      status: 404,
      type: 'text/plain'
    }
  ]

  for (const case_ of cases) {
    const response = await got(case_.url, { throwHttpErrors: false })
    assert.equal(case_.status, response.statusCode)
    assert.equal(case_.type, response.headers['content-type'])
    console.log(case_.url, 'ok')
  }
}

test()

xss.js

const fastify = require('fastify')
const he = require('he')
const got = require('got')
const assert = require('assert').strict

function server() {
  const app = fastify()
  app.get('/q', (request, response) => {
    try {
      if (request.query.message) {
        response.send(request.query.message.toUpperCase())
        return
      }
    } catch (error) {
      response.code(400).send('ERROR')
    }
  })
  return app
}

async function test () {
  const app = server()
  await app.listen(0)
  app.server.unref()

  const address = app.server.address()
  const url = `http://${address.address}:${address.port}`
  const response = await got(url + '/q?message=ciao', { throwHttpErrors: false })

  assert.equal(response.body, 'CIAO')
  assert.equal(response.headers['content-type'], 'text/plain; charset=utf-8')
  assert.equal(response.statusCode, 200)

  await app.close()
}

test()