App.hx

import js.Browser;
import mithril.M;

class App implements Mithril {
	public static function main() {
		M.mount(Browser.document.body, new App());
	}

	var tests = [];

	public function new() { 
		for (i in 0...5) {
			tests.push(M.component(new TestComponent()));
		}
	}

	public function view() m(".app", tests);
}

TestComponent.hx

import mithril.M;

class TestComponent implements Mithril {
	private static var nr = 0;
	@prop private var testVar : String;

	public function new() testVar = M.prop("test"+(nr++));

	public function view() m("p", testVar());
}