create-xcode-project

1. Delete the MainMenu.xib or Storyboard.main files.
2. Respectively, delete the NSMainNibFile or NSMainStoryboardFile keys in the project’s Info.plist.
3. Add a -NSConstraintBasedLayoutVisualizeMutuallyExclusiveConstraints YES launch argument.
4. Remove the @main attribute from the AppDelegate class.
5. Create a main.swift file, and add the code snippet below. Aside from bootstrapping the app, it checks whether the app is run within Xcode’s test environment. If so, the standard AppDelegate isn’t initialized. This speeds up the unit tests significantly (see this and this).

import Cocoa

let app = NSApplication.shared

if NSClassFromString("XCTestCase") != nil {
	app.run()
} else {
	let appDelegate = AppDelegate()
	app.delegate = appDelegate
	_ = NSApplicationMain(CommandLine.argc, CommandLine.unsafeArgv)
}

6. Create a menu bar (an instance of NSMenu) and assign it to the mainMenu property of the shared NSApplication instance.