/** * Tests abstract classes * * Copyright (C) 2010 Mike Gerwitz * * This file is part of ease.js. * * ease.js is free software: you can redistribute it and/or modify it under the * terms of the GNU Lesser General Public License as published by the Free * Software Foundation, either version 3 of the License, or (at your option) * any later version. * * This program is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License * for more details. * * You should have received a copy of the GNU Lesser General Public License * along with this program. If not, see . * * @author Mike Gerwitz * @package test */ var common = require( './common' ), assert = require( 'assert' ), Class = common.require( 'class' ), util = common.require( 'util' ); // not abstract var Foo = Class.extend( {} ); // abstract var AbstractFoo = Class.extend( { ctorCalled: false, __construct: function() { this.ctorCalled = true; }, 'abstract method': [ 'one', 'two', 'three' ], 'abstract second': [], }); // still abstract (didn't provide a concrete implementation of both abstract // methods) var SubAbstractFoo = AbstractFoo.extend( { second: function() { }, }); // concrete var ConcreteFoo = AbstractFoo.extend( { method: function( one, two, three ) { }, second: function() { }, }); assert.ok( ( Foo.isAbstract instanceof Function ), "All classes should have an isAbstract() method" ); assert.equal( Foo.isAbstract(), false, "Classes are not abstract if they contain no abstract methods" ); assert.equal( AbstractFoo.isAbstract(), true, "Classes should be considered abstract if they contain any abstract methods" ); assert.equal( SubAbstractFoo.isAbstract(), true, "Subtypes of abstract types are abstract if they don't provide a " + "concrete implementation for all abstract methods" ); assert.equal( ConcreteFoo.isAbstract(), false, "Subtypes of abstract types are not abstract if they provide concrete " + "implementations of all abstract methods" ); assert.throws( function() { new AbstractFoo(); new SubAbstractFoo(); }, Error, "Abstract classes cannot be instantiated" ); assert.ok( new ConcreteFoo(), "Concrete subclasses can be instantiated" ); assert.equal( ( new ConcreteFoo() ).ctorCalled, true, "Can call constructors of abstract supertypes" ); assert.throws( function() { AbstractFoo.extend( { // incorrect number of arguments method: function() { }, }); }, Error, "Concrete methods must implement the proper number of argments" ); assert.throws( function() { AbstractFoo.extend( { // incorrect number of arguments 'abstract method': [], }); }, TypeError, "Abstract methods of subtypes must implement the proper number of argments" ); assert.doesNotThrow( function() { AbstractFoo.extend( { // incorrect number of arguments 'abstract method': [ 'one', 'two', 'three', 'four' ], }); }, Error, "Abstract methods of subtypes may implement additional arguments, so long" + "as they implement at least the required number of arguments as defined by " + "it supertype" ); assert.doesNotThrow( function() { AbstractFoo.extend( { second: function( foo ) { }, }); }, Error, "Concrete methods needn't implement the proper number of arguments if " + "no definition was provided" ); assert.throws( function() { Class.extend( { // not an array (invalid) 'abstract foo': 'scalar', } ); }, TypeError, "Abstract methods must be declared as arrays" ); // otherwise it'll output the internal constructor code, which is especially // confusing since the user does not write it ( function testConvertingAbstractClassToStringYieldsClassString() { assert.equal( Class.extend( { 'abstract foo': [] } ).toString(), '', "Converting abstract class to string yields class string" ); } )();