A Swift version of https://scriptingosx.com/2018/01/get-an-icon-for-your-mac/ and https://gist.github.com/pudquick/1edd0d5e6c1ca5a1486bf727d071664e to create an icon for your Mac.

generateMacIcon.swift

#!/usr/bin/swift

import AppKit

func generateMacIcon(dimension: CGFloat, name iconName: String) {

	// Make sure our maximum rendering size does not exceed 512 px
	guard dimension <= 512 else {
		print("Error: Maximum dimension allowed is 512")
		return
	}

	// Make sure our minimum rendering size is greater than 0
	guard dimension > 0 else {
		print("Error: Please provide a non-negative dimension value")
		return
	}

	// Try to create an NSImage of the computer model if not bail out
	guard let image = NSImage(named: NSImage.Name.computer) else { return }

	// Set image size.
	image.size = NSMakeSize(dimension / 2, dimension / 2)

	// Create CGImage from NSImage
	if let cgImage = image.cgImage(forProposedRect: nil, context: nil, hints: nil) {
		let imageRep = NSBitmapImageRep.init(cgImage: cgImage)
		let pngData = imageRep.representation(using: .png, properties: [:])

		// Set current directory as output directory
		let destinationDir = URL(fileURLWithPath: "\(FileManager().currentDirectoryPath)")

		// Write PNG image to disk
		do {
			try pngData?.write(to: destinationDir.appendingPathComponent("\(iconName).png"), options: .withoutOverwriting)
		} catch {
			print(error.localizedDescription)
		}
	}
}

generateMacIcon(dimension: 512, name: "computer")