Tone.js/test/control/CtrlMarkov.js

import CtrlMarkov from "Tone/control/CtrlMarkov";
import Basic from "helper/Basic";

describe("CtrlMarkov", function(){

	Basic(CtrlMarkov);

	context("API", function(){

		it("can be constructed with a description and initial state", function(){
			var markov = new CtrlMarkov({
				"a" : ["a", "b"],
				"b" : ["b", "c"],
				"c" : "a"
			}, "a");
			expect(markov.values).to.have.keys(["a", "b", "c"]);
			expect(markov.value).to.equal("a");
			markov.dispose();
		});

		it("can move to the next state", function(){
			var markov = new CtrlMarkov({
				"a" : "b",
				"b" : "c",
				"c" : "a"
			}, "a");
			expect(markov.value).to.equal("a");
			expect(markov.next()).to.equal("b");
			expect(markov.value).to.equal("b");
			expect(markov.next()).to.equal("c");
			expect(markov.next()).to.equal("a");
			markov.dispose();
		});

		it("can move to the next with an array of options", function(){
			var markov = new CtrlMarkov({
				"a" : ["b", "c"],
				"b" : "a",
				"c" : "a"
			}, "a");
			expect(markov.value).to.equal("a");
			expect(markov.next()).to.satisfy(function(state){
				return state === "b" || state === "c";
			});
			expect(markov.next()).to.equal("a");
			markov.dispose();
		});

		it("can move to the next with an object of options", function(){
			var markov = new CtrlMarkov({
				"a" : [{
					"value" : "b",
					"probability" : 0.2
				}, {
					"value" : "c",
					"probability" : 0.9
				}],
				"b" : "a",
				"c" : "a"
			}, "a");
			expect(markov.value).to.equal("a");
			expect(markov.next()).to.satisfy(function(state){
				return state === "b" || state === "c";
			});
			expect(markov.next()).to.equal("a");
			markov.dispose();
		});

		it("stays on a state when it has no more options", function(){
			var markov = new CtrlMarkov({
				"a" : "end"
			}, "a");
			expect(markov.value).to.equal("a");
			expect(markov.next()).to.equal("end");
			expect(markov.next()).to.equal("end");
			markov.value = "a";
			expect(markov.value).to.equal("a");
			expect(markov.next()).to.equal("end");
			expect(markov.next()).to.equal("end");
			markov.dispose();
		});
	});
});