stateworks/test/test.js

Composable stateful objects

//////////////////////////////////////////////////////////////////////
// Node Stateworks UTs
// -----
// Copyright (c) Kiruse 2018 - 2021. Licensed under MIT License.
const {assert} = require('chai');
const Stateful = require('../index');

describe('stateworks', () => {
	it('should transition', () => {
		const stateful = Stateful((proxy, common, enter, me) => {
			const stateFoo = {
				foo() {
					assert.strictEqual(me(), stateFoo);
					enter(stateBar);
					return 'foo.foo';
				},
			};
			const stateBar = {
				foo() {
					assert.strictEqual(me(), stateBar);
					enter(stateBaz);
					return 'bar.foo';
				},
			};
			const stateBaz = {
				foo() {
					assert.strictEqual(me(), stateBaz);
					enter({});
					return 'baz.foo';
				}
			};
			
			return stateFoo;
		});
		
		assert.strictEqual(stateful.foo(), 'foo.foo');
		assert.strictEqual(stateful.foo(), 'bar.foo');
		assert.strictEqual(stateful.foo(), 'baz.foo');
		assert.strictEqual(stateful.foo, undefined);
	});
	
	it('should retain common props', () => {
		const stateful = Stateful((proxy, common, enter) => {
			Object.assign(common, {
				hello: 42,
				shared: 33,
			});
			
			const state1 = {
				foo() {
					this.hello = 'world';
					enter(state2);
				}
			};
			const state2 = {
				foo() {
					this.hello = 'bye';
					enter({});
				}
			}
			
			return state1;
		});
		
		assert.strictEqual(stateful.hello, 42);
		assert.strictEqual(stateful.shared, 33);
		
		stateful.foo();
		assert.strictEqual(stateful.hello, 'world');
		assert.strictEqual(stateful.shared, 33);
		
		stateful.foo();
		assert.strictEqual(stateful.hello, 'bye');
		assert.strictEqual(stateful.shared, 33);
	});
	
	it('should call transition handlers', () => {
		const checks = ['state1Enter', 'state1Leave', 'state2Enter', 'state2Leave'];
		
		const stateful = Stateful((proxy, common, enter) => {
			for (let key of checks) {
				common[key] = false;
			}
			
			const state1 = {
				onStateEnter(oldState, newState) {
					this.state1Enter = true;
					assert.isTrue(typeof(oldState) === 'object' && Object.keys(oldState).length === 0);
					assert.strictEqual(newState, state1);
				},
				onStateLeave(oldState, newState) {
					this.state1Leave = true;
					assert.strictEqual(oldState, state1);
					assert.strictEqual(newState, state2);
				},
				foo() {
					enter(state2);
				},
			};
			const state2 = {
				onStateEnter(oldState, newState) {
					this.state2Enter = true;
					assert.strictEqual(oldState, state1);
					assert.strictEqual(newState, state2);
				},
				onStateLeave(oldState, newState) {
					this.state2Leave = true;
					assert.strictEqual(oldState, state2);
					assert.strictEqual(newState, state3);
				},
				foo() {
					enter(state3);
				},
			};
			const state3 = {};
			
			return state1;
		});
		
		assert.isTrue(stateful.state1Enter);
		assert.isFalse(stateful.state1Leave);
		assert.isFalse(stateful.state2Enter);
		assert.isFalse(stateful.state2Leave);
		
		stateful.foo();
		
		assert.isTrue(stateful.state1Enter);
		assert.isTrue(stateful.state1Leave);
		assert.isTrue(stateful.state2Enter);
		assert.isFalse(stateful.state2Leave);
		
		stateful.foo();
		
		assert.isTrue(stateful.state1Enter);
		assert.isTrue(stateful.state1Leave);
		assert.isTrue(stateful.state2Enter);
		assert.isTrue(stateful.state2Leave);
	});
});