Raspberry Pi Node JS wifi and connection checker

index.js

const fs = require('fs')
const Wifi = require('rpi-wifi-connection')
const internetAvailable = require('internet-available')

const logIntervalMs = 1000 // 1000 * 60 * 10
const errIntervalMs = 5000

let lastLog = Date.now()

const wifi = new Wifi()

const logToFile = ({ text, fileName = 'log.txt' }) => {
  const date = new Date()
  const dateString = `${date.toLocaleDateString('en-UK')} ${date.toLocaleTimeString()}`
  const logLine = `${dateString}: ${text}\n`
  console.log(`logging ${logLine}`)
  fs.appendFile(`log/${fileName}`, logLine, err => {
    if (err) console.error('Cant write file!')
  })
}

setInterval(() => {
  console.log('getting status')
  wifi.getStatus().then(status => {
    console.log(status)
    if (status.ssid) {
      internetAvailable()
      .then(() => {
        // Do a normal log every 10 minutes just to prove the script hasn't died
        const now = Date.now()
        if (now > lastLog + logIntervalMs) {
          logToFile({ text: `${status.ssid}` })
          lastLog = now
        }
      })
      .catch(() => {
        logToFile({ text: `NO INTERNET: ${status.ssid}`, fileName: 'error.txt' })
      })
    } else {
      logToFile({ text: `NO WIFI`, fileName: 'error.txt' })
    }
  })
}, errIntervalMs);

package.json

{
  "name": "wifi-test",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "author": "",
  "license": "ISC",
  "dependencies": {
    "internet-available": "^1.0.0",
    "rpi-wifi-connection": "^1.0.14"
  }
}