Tone.js/test/core/Emitter.js

import Test from "helper/Test";
import Emitter from "Tone/core/Emitter";

describe("Emitter", function(){

	it("can be created and disposed", function(){
		var emitter = new Emitter();
		emitter.dispose();
		Test.wasDisposed(emitter);
	});

	it("can bind events", function(done){
		var emitter = new Emitter();
		emitter.on("something", function(){
			done();
			emitter.dispose();
		});
		emitter.emit("something");
		emitter.dispose();
	});

	it("can unbind events", function(){
		var emitter = new Emitter();
		var callback = function(){
			throw new Error("should call this");
		};
		emitter.on("something", callback);
		emitter.off("something", callback);
		emitter.emit("something");
		emitter.dispose();
	});

	it("removes all events when no callback is given", function(){
		var emitter = new Emitter();
		emitter.on("something", function(){
			throw new Error("should call this");
		});
		emitter.on("something", function(){
			throw new Error("should call this");
		});
		emitter.off("something");
		emitter.emit("something");
		emitter.off("something-else");
		emitter.dispose();
	});

	it("can remove an event while emitting", function(done){
		var emitter = new Emitter();
		emitter.on("something", function(){
			emitter.off("something");
		});
		emitter.on("something-else", function(){
			emitter.dispose();
			done();
		});
		emitter.emit("something");
		emitter.emit("something-else");
	});

	it("can invoke an event once", function(){
		var emitter = new Emitter();
		emitter.once("something", function(val){
			expect(val).to.equal(1);
		});
		emitter.emit("something", 1);
		emitter.emit("something", 2);
		emitter.dispose();
	});

	it("can pass arguments to the callback", function(done){
		var emitter = new Emitter();
		emitter.on("something", function(arg0, arg1){
			expect(arg0).to.equal("A");
			expect(arg1).to.equal("B");
			emitter.dispose();
			done();
		});
		emitter.emit("something", "A", "B");
	});

	it("can mixin its methods to another object", function(done){
		var emitter = {};
		Emitter.mixin(emitter);
		emitter.on("test", done);
		emitter.emit("test");
	});
});