Creates a favicon.svg from the current Git Branch

git-branch-to-favicon.js

const { execSync } = require('child_process')
const { createHash } = require('crypto')
const invertColor = require('invert-color')
const fs = require('fs')
const path = require('path')

/**
 * Returns numeronym string
 * @param str
 * @returns {*}
 */
const toNumeronym = (str) => {
  const lastIndex = str.length - 1

  return str[0] + str.substring(1, lastIndex).length + str[lastIndex]
}

/**
 * Returns a string removed from its vowels
 * @param str
 * @param limit
 * @returns {void | string | *}
 */
const disemvowel = (str, limit = 3) => {
  let chars = str.replace(/[aeiou]/gi, '')

  if (limit && chars.length > limit) {
    chars = chars[0] + chars.slice(-(limit - 1))
  }

  return chars
}

/**
 * Returns a shortname from the current git branch
 * @param disemvoweled
 * @param limit
 * @returns {any}
 */
const getShortname = (disemvoweled = true, limit = 3) => {
  const branchName = execSync('git rev-parse --abbrev-ref HEAD').toString()
  const n = branchName.indexOf('/')
  const branchType = branchName.substring(0, n != -1 ? n : branchName.length - 1)

  return disemvoweled ? disemvowel(branchType, limit) : toNumeronym(branchType)
}

/**
 * Returns a hex-color from a given string
 * @param str
 * @param inverted
 * @returns {*}
 */
const getColorFromStr = (str, inverted = false) => {
  const hash = createHash('sha256')
  hash.update(str)
  const color = '#' + hash.digest().toString('hex').substring(0, 6)

  return inverted ? invertColor(color, true) : color
}

/**
 * Returns an svg from the current git branch
 * @returns {string}
 */
const createSvg = () => {
  const shortName = getShortname()
  const color = getColorFromStr(shortName)
  const invertedColor = invertColor(color, true)

  return `<svg version="1.1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" x="0px" y="0px" viewBox="0 0 64 64" width="64px" height="64px">
        <circle cx="32" cy="32" fill="${color}" r="32"></circle>
        <text fill="${invertedColor}" x="32" y="32" font-family="'Fira Mono', monospace" font-size="24" text-anchor="middle" alignment-baseline="central">${shortName}</text>
    </svg>`
}

/**
 * Stores the svg as favicon
 */
(() => {
  const favicon = createSvg()
  const writeStream = fs.createWriteStream(path.join(process.cwd(), 'favicon.svg'))
  writeStream.write(favicon)
  writeStream.on('finish', () => {
    console.log('wrote all data to file')
  })
  writeStream.end()
})()