Calculation with side effects

code.js

function calculateAndSendContrast(foreground, alpha, backgound) {
// ...
  let contrast = foregroundLuminance / backgroundLuminance
  if (backgroundLuminance > foregroundLuminance) {
    contrast = 1 / contrast
  }
  contrast = Math.floor(contrast * 100) / 100
  return sendContrastInfo(contrast, foreground, backgound)
}