formatFileSize.js

export const formatFileSize = (bytes, fSExt = ['Bytes', 'KB', 'MB', 'GB']) => {
  // fSExt is an Array of unit labels
  let i = 0 // Index to track which unit to use
  while (bytes > 900) { // While the size is bigger than 900 in the current unit
    bytes /= 1024 // Convert to the next bigger unit
    i++ // Move to the next unit in the array
  }
  return (Math.round(bytes * 100) / 100) + ' ' + fSExt[i] // Round to 2 decimal places and append unit
}

// formatFileSize(500) // → "500 Bytes"
// formatFileSize(1024) // → "1 KB"
// formatFileSize(1536000) // → "1.46 MB"
// formatFileSize(1073741824) // → "1 GB"
// formatFileSize(950) // → "0.93 KB"  // Switches before hitting 1 KB because of the 900 threshold