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Initial implementation of natural class definition by invoking class module

closure/master
Mike Gerwitz 2011-03-03 19:43:20 -05:00
parent 15ac62d063
commit d23ae6210c
2 changed files with 288 additions and 194 deletions

View File

@ -35,6 +35,43 @@ var util = require( './util' ),
var class_meta = {};
/**
* This module may be invoked in order to provide a more natural looking class
* definition mechanism
*
* This may not be used to extend existing classes. To extend an existing class,
* use the class's extend() method. If unavailable (or extending a non-ease.js
* class/object), use the module's extend() method.
*
* @param {Object} def class definition
*
* @return {Class} new class
*/
module.exports = function( def )
{
// the class definition should be an object
if ( typeof def !== 'object' )
{
throw TypeError(
"Must provide class definition when declaring a new class"
);
}
// ensure we have the proper number of arguments (if they passed in too
// many, it may signify that they don't know what they're doing, and likely
// they're not getting the result they're looking for)
if ( arguments.length > 1 )
{
throw Error(
"Expecting one argument for Class definition; " +
arguments.length + " given."
);
}
return extend( def );
};
/**
* Creates a class, inheriting either from the provided base class or the
* default base class
@ -43,7 +80,7 @@ var class_meta = {};
*
* @return {Object} extended class
*/
exports.extend = function( base )
module.exports.extend = function( base )
{
return extend.apply( this, arguments );
};
@ -56,12 +93,12 @@ exports.extend = function( base )
*
* @return {Class} new class containing interface abstractions
*/
exports.implement = function()
module.exports.implement = function()
{
var args = Array.prototype.slice.call( arguments );
// apply to an empty (new) object
args.unshift( exports.extend() );
args.unshift( module.exports.extend() );
return implement.apply( this, args );
};
@ -74,7 +111,7 @@ exports.implement = function()
*
* @return {boolean} true if class (created through ease.js), otherwise false
*/
exports.isClass = function( obj )
module.exports.isClass = function( obj )
{
obj = obj || {};
@ -94,7 +131,7 @@ exports.isClass = function( obj )
* @return {boolean} true if instance of class (created through ease.js),
* otherwise false
*/
exports.isClassInstance = function( obj )
module.exports.isClassInstance = function( obj )
{
obj = obj || {};
@ -117,7 +154,7 @@ exports.isClassInstance = function( obj )
*
* @return {boolean} true if instance is an instance of type, otherwise false
*/
exports.isInstanceOf = function( type, instance )
module.exports.isInstanceOf = function( type, instance )
{
var meta, implemented, i;
@ -162,7 +199,7 @@ exports.isInstanceOf = function( type, instance )
* accurately conveys the act of inheritance, implementing interfaces and
* traits, etc.
*/
exports.isA = exports.isInstanceOf;
module.exports.isA = module.exports.isInstanceOf;
/**
@ -429,7 +466,7 @@ var implement = function()
}
// create a new class with the implemented abstract methods
var class_new = exports.extend( base, dest );
var class_new = module.exports.extend( base, dest );
getMeta( class_new.__cid ).implemented = implemented;
return class_new;
@ -594,7 +631,7 @@ function attachInstanceOf( instance )
{
var method = function( type )
{
return exports.isInstanceOf( type, instance );
return module.exports.isInstanceOf( type, instance );
};
util.defineSecureProp( instance, 'isInstanceOf', method );

View File

@ -30,200 +30,219 @@ var foo_props = {
one: 1,
two: 2,
},
Foo = Class.extend( foo_props );
assert.ok(
( Foo.extend instanceof Function ),
"Created class contains extend method"
);
// there are two different means of extending; we want to test them both
classes = [
Class.extend( foo_props ),
Class( foo_props ),
],
var sub_props = {
three: 3,
four: 4,
},
SubFoo = Foo.extend( sub_props );
class_count = classes.length
assert.ok(
( SubFoo instanceof Object ),
"Subtype is returned as an object"
);
// will hold the class being tested
Foo = null
;
// ensure properties were inherited from supertype
for ( var prop in foo_props )
// Run all tests for both. This will ensure that, regardless of how the class is
// created, it operates as it should. Fortunately, these tests are fairly quick.
for ( var i = 0; i < class_count; i++ )
{
Foo = classes[ i ];
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
);
}
var sub_instance = new SubFoo();
assert.ok(
( sub_instance instanceof Foo ),
"Subtypes are considered to be instances of their supertypes " +
"(via instanceof operator)"
);
assert.ok(
sub_instance.isInstanceOf( SubFoo ),
"Subtypes are considered to be instances of their supertypes (via " +
"isInstanceOf method)"
);
// Foo
// |
// SubFoo
// / \
// SubSubFoo SubSubFoo2
//
var SubSubFoo = SubFoo.extend(),
SubSubFoo2 = SubFoo.extend(),
sub_sub_instance = new SubSubFoo(),
sub_sub2_instance = new SubSubFoo2();
assert.ok(
( ( sub_sub_instance instanceof Foo )
&& sub_sub_instance.isInstanceOf( Foo )
),
"Sub-subtypes should be instances of their super-supertype"
);
assert.ok(
( !( sub_instance instanceof SubSubFoo )
&& !( sub_instance.isInstanceOf( SubSubFoo ) )
),
"Supertypes should not be considered instances of their subtypes"
);
assert.ok(
( !( sub_sub2_instance instanceof SubSubFoo )
&& !( sub_sub2_instance.isInstanceOf( 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(
foo_props[ prop ],
SubFoo.prototype[ prop ],
"Subtype inherits parent properties: " + prop
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"
);
}
// 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
);
}
var sub_instance = new SubFoo();
assert.ok(
( sub_instance instanceof Foo ),
"Subtypes are considered to be instances of their supertypes " +
"(via instanceof operator)"
);
assert.ok(
sub_instance.isInstanceOf( SubFoo ),
"Subtypes are considered to be instances of their supertypes (via " +
"isInstanceOf method)"
);
// Foo
// |
// SubFoo
// / \
// SubSubFoo SubSubFoo2
//
var SubSubFoo = SubFoo.extend(),
SubSubFoo2 = SubFoo.extend(),
sub_sub_instance = new SubSubFoo(),
sub_sub2_instance = new SubSubFoo2();
assert.ok(
( ( sub_sub_instance instanceof Foo )
&& sub_sub_instance.isInstanceOf( Foo )
),
"Sub-subtypes should be instances of their super-supertype"
);
assert.ok(
( !( sub_instance instanceof SubSubFoo )
&& !( sub_instance.isInstanceOf( SubSubFoo ) )
),
"Supertypes should not be considered instances of their subtypes"
);
assert.ok(
( !( sub_sub2_instance instanceof SubSubFoo )
&& !( sub_sub2_instance.isInstanceOf( 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"
);
// otherwise it'll output the internal constructor code, which is especially
// confusing since the user does not write it
@ -236,3 +255,41 @@ assert.ok(
);
} )();
( function testInvokingClassModuleRequiresObjectAsArgumentIfCreating()
{
assert.throws( function()
{
Class( 'moo' );
Class( 5 );
Class( false );
Class();
},
TypeError,
"Invoking class module requires object as argument if extending " +
"from base class"
);
var args = [ {}, 'one', 'two', 'three' ];
// we must only provide one argument if the first argument is an object (the
// class definition)
try
{
Class.apply( null, args );
// if all goes well, we don't get to this line
assert.fail(
"Only one argument for class definitions is permitted"
);
}
catch ( e )
{
assert.notEqual(
e.toString().match( args.length + ' given' ),
null,
"Class invocation should give argument count on error"
);
}
} )();