/** * Tests class module extend() method * * 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 */ require( './common' ); var assert = require( 'assert' ), Class = require( '../lib/class' ); var foo_props = { one: 1, two: 2, }, Foo = Class.extend( foo_props ); assert.ok( ( Foo.extend instanceof Function ), "Created class contains extend method" ); var sub_props = { three: 3, four: 4, }, SubFoo = Foo.extend( sub_props ); assert.ok( ( SubFoo instanceof Object ), "Subtype is returned as an object" ); // ensure properties were inherited from supertype for ( var prop in foo_props ) { assert.equal( foo_props[ prop ], SubFoo.prototype[ prop ], "Subtype inherits parent properties: " + prop ); } // and ensure that the subtype's properties were included for ( var prop in sub_props ) { assert.equal( sub_props[ prop ], SubFoo.prototype[ prop ], "Subtype contains its own properties: " + prop ); } assert.ok( ( new SubFoo() instanceof Foo ), "Subtypes must be considered to be instances of their supertypes" ); // Foo // | // SubFoo // / \ // SubSubFoo SubSubFoo2 // var SubSubFoo = SubFoo.extend(), SubSubFoo2 = SubFoo.extend(); assert.ok( ( new SubSubFoo() instanceof Foo ), "Sub-subtypes should be instances of their super-supertype" ); assert.ok( !( new SubFoo() instanceof SubSubFoo ), "Supertypes should not be considered instances of their subtypes" ); assert.ok( !( new SubSubFoo2() instanceof SubSubFoo ), "Subtypes should not be considered instances of their siblings" ); // to test inheritance of classes that were not previously created via the // Class.extend() method var OtherClass = function() {}; OtherClass.prototype = { foo: 'bla', }; var SubOther = Class.extend( OtherClass, { newFoo: 2, }); assert.equal( SubOther.prototype.foo, OtherClass.prototype.foo, "Prototype of existing class should be copied to subclass" ); assert.notEqual( SubOther.prototype.newFoo, undefined, "Subtype should contain extended members" ); assert.throws( function() { Class.extend( OtherClass, { foo: function() {}, }); }, TypeError, "Cannot override property with a method" ); var AnotherFoo = Class.extend( { arr: [], obj: {}, }); var Obj1 = new AnotherFoo(), Obj2 = new AnotherFoo(); Obj1.arr.push( 'one' ); Obj2.arr.push( 'two' ); Obj1.obj.a = true; Obj2.obj.b = true; // to ensure we're not getting/setting values of the prototype (=== can also be // used to test for references, but this test demonstrates the functionality // that we're looking to ensure) assert.ok( ( ( Obj1.arr[ 0 ] === 'one' ) && ( Obj2.arr[ 0 ] === 'two' ) ), "Multiple instances of the same class do not share array references" ); assert.ok( ( ( ( Obj1.obj.a === true ) && ( Obj1.obj.b === undefined ) ) && ( ( Obj2.obj.a === undefined ) && ( Obj2.obj.b === true ) ) ), "Multiple instances of the same class do not share object references" ); var arr_val = 1; var SubAnotherFoo = AnotherFoo.extend( { arr: [ arr_val ], }); var SubObj1 = new SubAnotherFoo(), SubObj2 = new SubAnotherFoo(); assert.ok( ( ( SubObj1.arr !== SubObj2.arr ) && ( SubObj1.obj !== SubObj2.obj ) ), "Instances of subtypes do not share property references" ); assert.ok( ( ( SubObj1.arr[ 0 ] === arr_val ) && ( SubObj2.arr[ 0 ] === arr_val ) ), "Subtypes can override parent property values" ); assert.throws( function() { Class.extend( { __initProps: function() {}, }); }, Error, "__initProps() cannot be declared (internal method)" ); var SubSubAnotherFoo = AnotherFoo.extend(), SubSubObj1 = new SubSubAnotherFoo(), SubSubObj2 = new SubSubAnotherFoo(); // to ensure the effect is recursive assert.ok( ( ( SubSubObj1.arr !== SubSubObj2.arr ) && ( SubSubObj1.obj !== SubSubObj2.obj ) ), "Instances of subtypes do not share property references" );