convert NSImage to pdf, basically the same as UIImage

NSImage_to_pdf.swift

import Cocoa
let a = #imageLiteral(resourceName: "hot.png")

extension NSImage {
    var toCGImage: CGImage {
        var imageRect = NSRect(x: 0, y: 0, width: size.width, height: size.height)
        guard let image =  cgImage(forProposedRect: &imageRect, context: nil, hints: nil) else {
            abort()
        }
        return image
    }
}


func createPDF(image: NSImage) -> NSData? {
    
    let pdfData = NSMutableData()
    
    let pdfConsumer = CGDataConsumer(data: pdfData as CFMutableData)!
    
    var mediaBox = NSRect.init(x: 0, y: 0, width: image.size.width, height: image.size.height)
    
    let pdfContext = CGContext(consumer: pdfConsumer, mediaBox: &mediaBox, nil)!

    pdfContext.beginPage(mediaBox: &mediaBox)
    pdfContext.draw(image.toCGImage , in: mediaBox)
    pdfContext.endPage()
    
    return pdfData
}

let documentDirectory = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!
let docURL = documentDirectory.appendingPathComponent("myFileName.pdf")
print(docURL)
try createPDF(image: a)?.write(to: docURL, atomically: true)


==================================

This also works, using PDFKit 

===================================


//: Playground - noun: a place where people can play

import Cocoa
import Quartz
// Create an empty PDF document
let pdfDocument = PDFDocument()

// Load or create your NSImage
let image = #imageLiteral(resourceName: "hot.png")

// Create a PDF page instance from your image
let pdfPage = PDFPage(image: image)

// Insert the PDF page into your document
pdfDocument.insert(pdfPage!, at: 0)

// Get the raw data of your PDF document
let data = pdfDocument.dataRepresentation()

// The url to save the data to
let documentDirectory = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!
let docURL = documentDirectory.appendingPathComponent("myFileName.pdf")


try data?.write(to: docURL)
// Save the data to the url
print(docURL)

Thank you! This helped me!

I had to add pdfContext.closePDF() after endPage() to make it generate a PDF that I can open.