Attempting to Highlight First Letter

highlightFirstLetter.js

// Create a text layer within an artboard and select the layer to run properly

let Sketch = require('sketch')
let ShapePath = Sketch.ShapePath
let Rectangle = Sketch.Rectangle

// Removes old highlight layer so you can repeatedly run this code
let doc = Sketch.getSelectedDocument()
let oldHighlight = doc.pages[0].layers[0].layers.find(layer => layer.name=="highlight")
if (oldHighlight) { oldHighlight.remove() }

let selection = context.selection[0]
let jsSelect = Sketch.fromNative(selection)
let textLayerSize = selection.frame().size()
let attrString = selection.attributedStringValue()
let stringValue = selection.stringValue()

let textContainer = NSTextContainer.alloc().init()
textContainer.size = CGSizeMake(
    textLayerSize.width,
    Number.MAX_VALUE
);

let layoutManager = NSLayoutManager.alloc().init()
let textStorage = NSTextStorage.alloc().init()
textStorage.setAttributedString(attrString)
textStorage.addLayoutManager(layoutManager)
layoutManager.addTextContainer(textContainer)

// Get frame of first letter
let frame = [layoutManager boundingRectForGlyphRange:NSMakeRange(0,1) inTextContainer:textContainer]

let rect = new Rectangle(frame)
// Reposition rect to origin of selection
rect.offset(selection.frame().x(),selection.frame().y())

let highlight = new ShapePath({
  name: 'highlight',
  frame: rect,
  style: { fills: ["#FF0000"]},
  parent: jsSelect.parent,
})
highlight.moveToBack()