GitHub Receipts | Credit @aschmelyun https://twitter.com/aschmelyun/status/1506960015063625733

index.mjs

import { createServer } from 'node:http'
import { createHmac } from 'node:crypto'
import { Printer, InMemory, Drawer, Style, Align, Model } from 'escpos-buffer'

const {
  PORT = 3000,
  HOST = 0,
  GITHUB_WEBHOOK_SECRET,
  PRINTER_MODEL = 'TM-T20',
  PRINTER_COLUMNS = 56
} = process.env

createServer(async (req, res) => {
  let bodyChunks = []
  req.on('data', chunk => bodyChunks.push(chunk))
  req.on('end', async () => {
    const rawBody = Buffer.concat(bodyChunks).toString('utf8')
    const jsonBody = JSON.parse(rawBody)
    const signature = req.headers['x-hub-signature-256']
    const computedSignature =
      'sha256=' +
      createHmac('sha256', GITHUB_WEBHOOK_SECRET).update(rawBody).digest('hex')

    if (computedSignature === signature) {
      const connection = new InMemory()
      const model = new Model(PRINTER_MODEL)
      const printer = await Printer.CONNECT(model, connection)

      await printer.setColumns(PRINTER_COLUMNS)
      await printer.write(jsonBody.action)
      await printer.write(jsonBody.issue?.title)
      await printer.write(jsonBody.issue?.number)
     
      await printer.feed(6)
      await printer.buzzer()
      await printer.cutter()
      await printer.drawer(Drawer.First)

      process.stdout.write(connection.buffer())
    }
  })
}).listen(PORT, HOST)

$ node index.mjs | lp -d [PRINTER_MODEL]