ae-biu/src/ae-mock.js

Born For AE, Born To Do

#!/usr/bin/env node
// @flow

import program from 'commander'
import fs from 'fs'
import path from 'path'
import isEqual from 'lodash/isEqual'
import enableDestroy from 'server-destroy'
import logger from './utils/logger'
import { mockDir } from './utils/paths'
import clearConsole from './utils/clear-console'

/**
 * Usage
 */
program
  .usage('[options]')
  .option('-p, --port', 'Mock server port, default is 9000')
  .option('-w, --watch', 'Watch db.json change, default is false')
  .parse(process.argv)

// padding
console.log()

// options
const port = (+program.args[0]) || 9000
const watch = program.watch

// must require in here
const createServer = require('./config/mock-server.config')
const dbPath = path.resolve(mockDir, 'db.json')

// start server
let app
let db

const start = () => {
  db = JSON.parse(fs.readFileSync(dbPath, { encoding: 'utf8' }))
  app = createServer().listen(port, () => {
    logger.info(`Mock Server now running at http://0.0.0.0:${port}\n`)
  })
  enableDestroy(app)
}

start()

// from https://github.com/typicode/json-server/blob/master/src/cli/run.js#L199
if (watch) {
  logger.info('Watching database...\n')
  let readError = false
  fs.watch(mockDir, (event, file) => {
    if (file) {
      const watchedFile = path.resolve(mockDir, file)
      if (watchedFile === dbPath) {
        let obj
        try {
          obj = JSON.parse(fs.readFileSync(watchedFile, { encoding: 'utf8' }))
          if (readError) {
            logger.info(`Read error has been fixed :)\n`)
            readError = false
          }
        } catch (e) {
          readError = true
          logger.error(`Error reading ${watchedFile}\n`)
          console.error(e.message)
          return
        }

        // Compare .json file content with in memory database
        const isDatabaseDifferent = !isEqual(obj, db)
        if (isDatabaseDifferent) {
          clearConsole()
          logger.info(`database has changed, reloading...\n`)
          app && app.destroy()
          start()
        }
      }
    }
  })
}