conditional-chain

Bring some logic to js waterfalls

Before:

let num = Math.pow(2, 10)
if (isEngineeringMode) num = num.toExponential()
if (toUpper) num = num.toUpperCase()
return num

After:

const num = cond(Math.pow(2, 10))
  .if(isEngineeringMode, num => num.toExponential())
  .if(toUpper, num => num.toUpperCase())
  .end()

return num