Calculates unequal but proportional pieces of 100%

proportionalPieces.js

//used this through trial and error to find the correct proportions for a progress bar where one element is 10%, with 5 pieces
//based on https://stackoverflow.com/a/40094266/102960

function proportionalPieces(proportion, size) {
  const pieces = [1]
  for (let i = 1; i < size; i++) {
    pieces[i] = pieces[i-1] * proportion
  }
  
  const sum = pieces.reduce((acc, piece) => acc + piece)
  const correctionRatio = 100 / sum
  
  for (i = 0; i < size; i++) {
    pieces[i] *= correctionRatio
  }
  
  return pieces
}