/** * Tests class module constructor creation * * Copyright (C) 2010, 2011, 2012 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 */ var common = require( './common' ), assert = require( 'assert' ), Class = common.require( 'class' ); // these two variables are declared outside of the class to ensure that they // will still be set even if the context of the constructor is wrong var construct_count = 0, construct_context = null, construct_args = null, // create a basic test class Foo = Class.extend( { __construct: function() { construct_count++; construct_context = this; construct_args = arguments; }, }) ; assert.ok( ( Foo.prototype.__construct instanceof Function ), "Provided properties should be copied to the new class prototype" ); assert.equal( construct_count, 0, "Constructor should not be called before class is instantiated" ); var args = [ 'foo', 'bar' ], obj = new Foo( args[0], args[1] ); assert.equal( construct_count, 1, "Constructor should be invoked once the class is instantiated" ); assert.equal( construct_context.__iid, obj.__iid, "Constructor should be invoked within the context of the class instance" ); assert.notEqual( construct_args, null, "Constructor arguments should be passed to the constructor" ); assert.equal( construct_args.length, args.length, "All arguments should be passed to the constructor" ); // check the argument values for ( var i = 0, len = args.length; i < len; i++ ) { assert.equal( construct_args[ i ], args[ i ], "Arguments should be passed to the constructor: " + i ); } var SubFoo = Foo.extend( { args: [ 'should', 'be', 'overwritten' ], } ); construct_count = 0; construct_context = null; var args2 = [ 'fried', 'pickle' ], subobj = new SubFoo( args2[ 0 ], args2[ 1 ] ); assert.equal( construct_count, 1, "Parent constructor should be called for subtype if not overridden" ); assert.equal( construct_context.__iid, subobj.__iid, "Parent constructor is run in context of the subtype" ); // this should be implied by the previous test, but let's add it for some peace // of mind assert.ok( ( ( construct_args[ 0 ] === args2[ 0 ] ) && ( construct_args[ 1 ] == args2[ 1 ] ) ), "Parent constructor sets values on subtype" ); var subobj2 = SubFoo( args2[ 0 ], args2[ 1 ] ); assert.ok( ( subobj2 instanceof SubFoo ), "Constructor is self-invoking" ); assert.equal( construct_context.__iid, subobj2.__iid, "Self-invoking constructor is run in the context of the new object" ); assert.ok( ( ( construct_args[ 0 ] === args2[ 0 ] ) && ( construct_args[ 1 ] == args2[ 1 ] ) ), "Self-invoking constructor receives arguments" ); /** * In PHP, one would prevent a class from being instantiated by declaring the * constructor as protected or private. To me, this is cryptic. A better method * would simply be to throw an exception. Perhaps, in the future, an alternative * will be provided for consistency. * * The constructor must be public. */ ( function testConstructorCannotBeDeclaredAsProtectedOrPrivate() { assert['throws']( function() { Class( { 'protected __construct': function() {} } ); }, TypeError, "Constructor cannot be protected" ); assert['throws']( function() { Class( { 'private __construct': function() {} } ); }, TypeError, "Constructor cannot be private" ); } )(); /** * When a constructor is instantiated, the instance's 'constructor' property is * set to the constructor that was used to instantiate it. The same should be * true for class instances. * * This will also be important for reflection. */ ( function testConsructorPropertyIsProperlySetToClass() { var Foo = Class( {} ); assert.ok( Foo().constructor === Foo, "Instance constructor should be set to class" ); } )();