Javascript: HEX to RGB to HSL

hex2hsl.js

fucntion hexToHSL(hex) {
  const result = /^#?([a-f\d]{2})([a-f\d]{2})([a-f\d]{2})$/i.exec(hex)
  const r = parseInt(result[1], 16) / 255
  const g = parseInt(result[2], 16) / 255
  const b = parseInt(result[3], 16) / 255
  const max = Math.max(r, g, b)
  const min = Math.min(r, g, b)
  let h = 0
  let s = 0
  const l = (max + min) / 2
  if (max === min) {
    h = s = 0 // achromatic
  } else {
    const d = max - min
    s = l > 0.5 ? d / (2 - max - min) : d / (max + min)
    switch (max) {
      case r:
        h = (g - b) / d + (g < b ? 6 : 0)
        break
      case g:
        h = (b - r) / d + 2
        break
      case b:
        h = (r - g) / d + 4
        break
    }
    h /= 6
  }
  const HSL = { h: h * 360, s: s * 100, l: l * 100 }
  return HSL
}