fetch-fixtures.js

const fs = require('fs/promises')
const { createWriteStream, createReadStream } = require('fs')
const crypto = require('crypto')
const { buildNum, sha } = require('./_test/all.meta.json')
const update = process.argv[2] === 'latest'
const dataUrl = `https://raw.githubusercontent.com/nornagon/cdda-data/main/data/${update ? 'latest' : buildNum}/all.json`

function computeSha(file) {
  return new Promise((resolve) => {
    const hash = crypto.createHash('sha256')
    const s = createReadStream(file)
    s.on('data', d => hash.update(d))
    s.on('end', () => {
      resolve(hash.digest('hex'))
    })
  })
}

async function matchesSha(file, sha) {
  return sha === await computeSha(file)
}

;(async () => {
  const filename = __dirname + '/_test/all.json'
  if (!await fs.access(filename).then(() => true, () => false)) {
    console.log('Test data not present, fetching...')
  } else if (!await matchesSha(filename, sha) || update) {
    if (update)
      console.log('Updating test data...')
    else
      console.log('Test data not up-to-date, fetching...')
  } else {
    return
  }
  const res = await require('node-fetch')(dataUrl)
  const dest = createWriteStream(filename);
  res.body.pipe(dest);
  res.body.on('end', async () => {
    const sha = await computeSha(filename)
    const buildNum = JSON.parse(await fs.readFile(filename, 'utf8')).build_number
    await fs.writeFile(__dirname + '/_test/all.meta.json', JSON.stringify({buildNum, sha}))
  });
})()