Adobe Illustrator script to resize objects proportionally to fit inside the artboard.

AiFitToArtboard.jsx

/***************************
 NOT MAINTAINED! from ~2014
****************************/

// cs4+ script for resizing objects proportionally to fit inside artboard
// based on: https://forums.adobe.com/message/4164590
// usage: create a new document with desired artboard size, paste object, select it, run this script
// bugs: centering does not work after changing artboard size

var activeDoc = app.activeDocument
var selection = activeDoc.selection

// check if anything is selected
if (selection.length > 0) {
  for (var i = 0; i < selection.length; i++) {
    var item = selection[i].duplicate()

    var abActive =
      activeDoc.artboards[activeDoc.artboards.getActiveArtboardIndex()]

    var abProps = getArtboardBounds(abActive)
    var boundsDiff = itemBoundsDiff(selection[i])

    fitItem(item, abProps, boundsDiff) // scale object to fit artboard
  }
} else {
  alert('Select an object before running this script')
}

function getArtboardBounds(artboard) {
  var bounds = artboard.artboardRect

  var left = bounds[0]
  var top = bounds[1]
  var right = bounds[2]
  var bottom = bounds[3]

  var width = right - left
  var height = top - bottom

  var props = { left: left, top: top, width: width, height: height }

  return props
}

function itemBoundsDiff(item) {
  var itemVB = item.visibleBounds

  var itemVW = itemVB[2] - itemVB[0] // right - left
  var itemVH = itemVB[1] - itemVB[3] // top - bottom

  var itemGB = item.geometricBounds

  var itemGW = itemGB[2] - itemGB[0] // right - left
  var itemGH = itemGB[1] - itemGB[3] // top - bottom

  var deltaX = itemVW - itemGW
  var deltaY = itemVH - itemGH

  var diff = { deltaX: deltaX, deltaY: deltaY }

  return diff
}

function fitItem(item, props, diff) {
  var oldWidth = item.width
  var oldHeight = item.height

  if (item.width > item.height) {
    // landscape, scale height using ratio from width
    item.width = props.width - diff.deltaX
    var ratioW = item.width / oldWidth
    item.height = oldHeight * ratioW
  } else {
    // portrait, scale width using ratio from height
    item.height = props.height - diff.deltaY
    var ratioH = item.height / oldHeight
    item.width = oldWidth * ratioH
  }

  // center
  item.top = 0 - (props.height / 2 - item.height / 2)
  item.left = props.width / 2 - item.width / 2

  // deselect
  item.selected = false
}

Check this out:
https://gist.github.com/shivendra14/5147b529001da1458a0017c866f633b9

modified this to scale artwork and artboard :)

and this one to scale up assets:
https://gist.github.com/shivendra14/f135d6279a20053a62a798be5da5e174

Hi Your script works great but i need to scale the object with scale & stroke effects on. Is it possible, please help me

This script is almost there... on Illustrator CC it doesn't place the resized object in its parent artboard. I'm an amateur at ExtendScript - hoping for a fix!