Loading a XIB file in a Sketch plugin

HSMain.m

#import "HSMain.h"
@import AppKit;

@implementation HSMain

- (NSString *)helloText {
	NSLog(@"HelloSketch (Sketch Plugin)");
	return @"Hiya, sending singal from HSMain";
}

- (id)loadNibFile {
	// The myNib file must be in the bundle that defines self's class.
	NSArray *topLevelObjects;
	NSBundle *myBundle = [NSBundle bundleForClass:[HSMain class]];
	if (! [myBundle loadNibNamed:@"HSPanel" owner:self topLevelObjects:&topLevelObjects])
	{
		NSLog(@"Warning! Could not load myNib file.\n");
		return NULL;
	} else {
		return topLevelObjects;
	}
}

@end

script.js

let sketch = require('sketch')

var onRun = function(context) {
    try {
        runPlugin()
    }
    catch(e) {
        let pluginURL = context.plugin.url()
        let bundlePath = NSBundle.bundleWithURL(pluginURL).resourceURL().path()
        let loadFramework = Mocha.sharedRuntime().loadFrameworkWithName_inDirectory('HelloSketch', bundlePath)
        console.log(pluginURL, bundlePath, loadFramework)
        if (loadFramework) {
            runPlugin()
        }
    }
};


function runPlugin() {
    let main = HSMain.alloc().init()
    sketch.UI.message(main.helloText())
    console.log(main.loadNibFile())
}