Moved test-class-constructor into suite as Class/ConstructorTest

Also removed assertions that are performed elsewhere.

We broke onto the fifth line in the suite ;)

test/Class/ConstructorTest.js

@@ -0,0 +1,203 @@
+/**
+ * Tests class module constructor creation
+ *
+ *  Copyright (C) 2010, 2011, 2012, 2013 Mike Gerwitz
+ *
+ *  This file is part of GNU ease.js.
+ *
+ *  ease.js is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU 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 General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+require( 'common' ).testCase(
+{
+    setUp: function()
+    {
+        this.Sut = this.require( 'class' );
+    },
+
+
+    /**
+     * As a sanity check, ensure that the constructor is not invoked upon
+     * defining the class. (Note that the case of ensuring that it is not
+     * called when creating a subtype is handled by the ExtendTest case.)
+     */
+    'Constructor should not be invoked before instantiation': function()
+    {
+        var called = false;
+        this.Sut.extend( { __construct: function() { called = true; } } );
+
+        this.assertNotEqual( called, true );
+    },
+
+
+    /**
+     * Since __construct is a special method that is not recognized by
+     * ECMAScript itself, we must ensure that it is invoked when the class
+     * is instantiated. Further, it should only be called a single time,
+     * which is particularly important if it produces side-effects.
+     */
+    'Constructor should be invoked once upon instantiation': function()
+    {
+        var called = 0;
+
+        var Foo = this.Sut.extend(
+        {
+            __construct: function() { called++; }
+        } );
+
+        // note that we're not yet testing the more consise new-less
+        // invocation style
+        new Foo();
+        this.assertEqual( called, 1 );
+    },
+
+
+    /**
+     * Once invoked, the __construct method should be bound to the newly
+     * created instance.
+     */
+    'Constructor should be invoked within context of new instance':
+    function()
+    {
+        var expected = Math.random();
+
+        var Foo = this.Sut.extend(
+            {
+                val: null,
+                __construct: function() { this.val = expected; }
+            } );
+
+        // if `this' was bound to the instance, then __construct should set
+        // VAL to EXPECTED
+        var inst = new Foo();
+        this.assertEqual( inst.val, expected );
+    },
+
+
+    /**
+     * All arguments passed to the constructor (that is, by invoking the
+     * ``class'') should be passed to __construct, unchanged and
+     * uncopied---that is, references should be retained.
+     */
+    'Constructor arguments should be passed unchanged to __construct':
+    function()
+    {
+        var args  = [ "foo", { bar: 'baz' }, [ 'moo', 'cow' ] ],
+            given = null;
+
+        var Foo = this.Sut.extend(
+        {
+            __construct: function()
+            {
+                given = Array.prototype.slice.call( arguments, 0 );
+            }
+        } );
+
+        new Foo( args[ 0 ], args[ 1 ], args[ 2 ] );
+
+        // make sure we have everything and didn't get anything extra
+        this.assertEqual( given.length, args.length );
+
+        var i = args.length;
+        while ( i-- )
+        {
+            this.assertStrictEqual( given[ i ], args[ i ],
+                "Ctor argument mismatch: " + i
+            );
+        }
+    },
+
+
+    /**
+     * If a subtype does not define its own constructor, then its parent's
+     * should be called by default. Note that this behavior---as is clear by
+     * the name __construct---is modelled after PHP; Java classes, for
+     * instance, do not inherit their parents' constructors.
+     */
+    'Parent constructor should be invoked for subtype if not overridden':
+    function()
+    {
+        var called = false;
+
+        var Sub = this.Sut.extend(
+        {
+            __construct: function() { called = true; }
+        } ).extend( {} );
+
+        new Sub();
+        this.assertOk( called );
+    },
+
+
+    /**
+     * Classes created through ease.js do not require use of the `new'
+     * keyword, which allows for a much more natural, concise, and less
+     * error-prone syntax. Ensure that a new instance is created even when
+     * it is omitted.
+     *
+     * The rest of the tests above would then stand, since they use the
+     * `new' keyword and this concise format has no choice but to ultimately
+     * do the same; otherwise, it would not be recognized by instanceof.
+     */
+    'Constructor does not require `new\' keyword': function()
+    {
+        var Foo = this.Sut.extend( {} );
+
+        this.assertOk( new Foo() instanceof Foo );  // sanity check
+        this.assertOk( Foo() instanceof Foo );
+    },
+
+
+
+    /**
+     * In certain OO languages, one would prevent a class from being
+     * instantiated by declaring the constructor as protected or private. To
+     * me (Mike Gerwitz), 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. (It is for this reason that you will
+     * often see the convention of omitting visibility keywords entirely for
+     * __construct, since public is the default and there is no other
+     * option.)
+     */
+    '__construct must be public': function()
+    {
+        var Sut = this.Sut;
+
+        this.assertThrows( function()
+        {
+            Sut( { 'protected __construct': function() {} } );
+        }, TypeError, "Constructor should not be able to be protected" );
+
+        this.assertThrows( function()
+        {
+            Sut( { 'private __construct': function() {} } );
+        }, TypeError, "Constructor should not be able to be private" );
+    },
+
+
+    /**
+     * When a constructor is instantiated conventionally in ECMAScript, 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.
+     */
+    '`constructor\' property is properly set to class object': function()
+    {
+        var Foo = this.Sut.extend( {} );
+        this.assertStrictEqual( Foo().constructor, Foo );
+    },
+} );