convert loopback yaml models to json

loopback-models.js

/**
 * convert models-yaml/*.yaml file to models/*.json
 */

/* eslint no-console: off */

const yaml = require('js-yaml')
const {resolve, basename} = require('path')
const fs = require('fs')

const HELP = `
  scripts/models.js [OPTIONS] dirname

  dirname    basedir should contain \`models-yaml\` and
             \`models\` directory

  OPTIONS:

  -f|--file filename  process filename
  -h|--help           This help
`

/**
 * parse arguments
 */
function cmd () {
  const args = process.argv.slice(2)
  const o = {}
  while (args.length) {
    const arg = args.shift()
    if (/^-h|--help$/.test(arg)) {
      o.help = true
    } else if (/^-f|--file$/.test(arg)) {
      o.file = arg.shift()
    } else {
      o.dir = arg
    }
  }
  return o
}

/**
 * get yaml files from `dirname`
 */
function dirFiles (dirname) {
  const files = fs.readdirSync(dirname)
    .filter(file => /\.yaml$/.test(file))
    .map(file => resolve(dirname, file))
  return files
}

/**
 * get target filename from `filename` and `basedir`
 */
function targetFile (filename, basedir) {
  const targetDir = resolve(basedir, 'models')
  const name = basename(filename)
  let out = resolve(targetDir, name)
  if (name === 'model-config.yaml') {
    out = resolve(basedir, name)
  }
  return out.replace(/\.yaml$/, '.json')
}

/**
 * convert yaml file to json
 */
function toJson (filename, basedir) {
  const target = targetFile(filename, basedir)
  const data = fs.readFileSync(filename, 'utf8')
  const doc = yaml.safeLoad(data)
  fs.writeFileSync(target, JSON.stringify(doc, null, 2) + '\n', 'utf8')
}

function main (obj) {
  const o = cmd()
  if (o.help) {
    console.log(HELP)
    return process.exit(0)
  }
  const basedir = o.dir || resolve(__dirname, '../server')
  const source = resolve(basedir, 'models-yaml')
  let files
  if (o.file) {
    files = [o.file]
  } else {
    files = dirFiles(source)
  }
  files.forEach(file => toJson(file, basedir))
}

main()