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Overriding vanilla prototype methods no longer errors

This is something that I've been aware of for quite some time, but never got
around to fixing; ease.js had stalled until it was revitalized by becoming a
GNU project.
protolib
Mike Gerwitz 2014-04-23 01:50:35 -04:00
parent aa0003d239
commit 7f3e7fba35
2 changed files with 115 additions and 1 deletions

View File

@ -120,11 +120,16 @@ exports.buildMethod = function(
members, meta, name, value, keywords, instCallback, cid, base, state members, meta, name, value, keywords, instCallback, cid, base, state
) )
{ {
// these defaults will be used whenever a keyword set is unavailable,
// which should only ever be the case if we're inheriting from a
// prototype rather than an ease.js class/etc
var kdefaults = this._methodKeywordDefaults;
// TODO: We can improve performance by not scanning each one individually // TODO: We can improve performance by not scanning each one individually
// every time this method is called // every time this method is called
var prev_data = scanMembers( members, name, base ), var prev_data = scanMembers( members, name, base ),
prev = ( prev_data ) ? prev_data.member : null, prev = ( prev_data ) ? prev_data.member : null,
prev_keywords = ( prev && prev.___$$keywords$$ ), prev_keywords = ( prev && ( prev.___$$keywords$$ || kdefaults ) ),
dest = getMemberVisibility( members, keywords, name ); dest = getMemberVisibility( members, keywords, name );
; ;
@ -194,6 +199,13 @@ exports.buildMethod = function(
}; };
/**
* Default keywords to apply to methods inherited from a prototype.
* @type {Object}
*/
exports._methodKeywordDefaults = { 'virtual': true };
/** /**
* Creates an abstract override super method proxy to NAME * Creates an abstract override super method proxy to NAME
* *

View File

@ -0,0 +1,102 @@
/**
* Tests class interoperability with vanilla ECMAScript
*
* Copyright (C) 2014 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/>.
*
* Note that these tests all use the `new' keyword for instantiating
* classes, even though it is not required with ease.js; this is both for
* historical reasons (when `new' was required during early development) and
* because we are not testing (and do want to depend upon) that feature.
*/
require( 'common' ).testCase(
{
caseSetUp: function()
{
this.Class = this.require( 'class' );
},
/**
* While this may seem at odds with ease.js' philosophy (because ease.js
* methods are *not* virtual by default), we do not have much choice in
* the matter: JavaScript is very lax and does not offer a way to
* declare something as virtual or otherwise. Given that, we have to
* choose between implicit virtual methods, or never allowing the user
* to override methods inherited from a prototype. The latter is not a
* wise choice, since there would be no way to change that behavior.
*
* Of course, if such a distinction were important, a wrapper class
* could be created that simply extends the prototype, marks methods
* virtual as appropriate, and retain only that reference for use from
* that point forward.
*/
'Methods inherited from a prototype are implicitly virtual': function()
{
var expected = {};
var P = function()
{
this.foo = function()
{
return null;
};
}
var Class = this.Class,
inst;
// if an error is thrown here, then we're probably not virtual
this.assertDoesNotThrow( function()
{
inst = Class.extend( P,
{
'override foo': function()
{
return expected;
}
} )();
} );
// the sky is falling if the above worked but this didn't
this.assertStrictEqual( inst.foo(), expected );
},
/**
* Complement to the above test.
*/
'Prototype method overrides must provide override keyword': function()
{
var P = function()
{
this.foo = function() {};
};
var Class = this.Class;
this.assertThrows( function()
{
Class.extend( P,
{
// missing override keyword
foo: function() {},
} );
} );
},
} );