pdftest/src/server/serve.js

Client-side visual testing library for PDFs

import express from 'express'
import cors from 'cors'
import path from 'path'
import fs from 'fs'

function writeFile(filePath, data) {
  fs.mkdirSync(path.dirname(filePath), { recursive: true })
  fs.writeFileSync(filePath, data)
}

function handlePostPut(root) {
  return (req, res, next) => {
    const requestedFile = path.join(root, req.url)

    switch (req.method) {
      case 'POST':
        if (fs.existsSync(requestedFile)) { req.method = 'GET'; break }
      case 'PUT':
        writeFile(requestedFile, req.body)
        req.method = 'GET'
    }

    next()
  }
}

function handleHandshake(req, res, next) {
  if (['GET', 'HEAD'].includes(req.method) && req.url === '/') {
    return res.status(200).end()
  }
  next()
}

function setupServer(root, options) {
  const app = express()
  app.use(cors())
  app.use(express.raw({ type: ['application/octet-stream', 'application/pdf'], limit: options.limit || '100mb' }))
  app.use(handlePostPut(root))
  app.use(handleHandshake)
  app.use(express.static(root))

  return app
}

function serve(port = 8000, root = '.', options = {}) {
  const app = setupServer(root, options)

  return new Promise((resolve, reject) => {
    const server = app.listen(port, () => {
      const optionsText = JSON.stringify(options) === '{}' ? '' : ` with options ${JSON.stringify(options)}`;
      options.verbose && console.log(`pdftest: Serving '${root}' at http://localhost:${port}${optionsText}`)
      resolve(server)
    })

    process.on('uncaughtException', reject)
  })
}

export default serve