easejs/test/test-util-clone.js

/**
 * Tests util.clone
 *
 *  Copyright (C) 2010, 2011 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 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/>.
 *
 * @author  Mike Gerwitz
 */

var common = require( './common' ),
    assert = require( 'assert' ),
    util   = common.require( 'util' );

var arr = [ 1, 2, 3 ],
    obj = { a: 1, b: 2 };

var arr2 = util.clone( arr ),
    obj2 = util.clone( obj );

assert.ok(
    ( arr !== arr2 ),
    "Cloned array is not the same object as the original"
);

assert.ok(
    ( obj !== obj2 ),
    "Cloned object is not the same object as the original"
);

// ensure array was properly cloned
for ( var i = 0, len = arr.length; i < len; i++ )
{
    assert.equal(
        arr2[ i ],
        arr[ i ],
        "Array data is properly cloned"
    );
}

// ensure object was properly cloned
for ( var prop in obj )
{
    assert.equal(
        obj2[ prop ],
        obj[ prop ],
        "Object data is properly cloned"
    );
}


//
// deep clone
var deep_arr = [ [ 1, 2 ], [ 3, 4 ], [ 5, [ 6, 7 ] ], { a: 1 } ],
    deep_obj = { a: [ 1 ], b: [ 2 ], c: { d: 3 } },

    deep_arr2 = util.clone( deep_arr, true ),
    deep_obj2 = util.clone( deep_obj, true ),

    deep_i = 0;

// ensure that the cloned values still match
assert.deepEqual(
    deep_arr2,
    deep_arr,
    "Deep cloned values are equal"
);

assert.deepEqual(
    deep_obj2,
    deep_obj,
    "Deep cloned values are equal"
);

deep_i = deep_arr.length;
while ( deep_i-- )
{
    assert.ok(
        ( deep_arr2[ i ] !== deep_arr[ i ] ),
        "Deep cloned array's values are cloned"
    );
}

for ( var prop in deep_obj )
{
    assert.ok(
        ( deep_obj2[ prop ] !== deep_obj[ prop ] ),
        "Deep cloned object's values are cloned (" + prop + ")"
    );
}


/**
 * "Cloning" functions doesn't necessarily make sense. It can, depending on how
 * you think about it. We can do a toSource() in many circumstances and create a
 * new function from that. But what's the point? It still does the same thing.
 * As such, functions will not be cloned. They'll be returned by reference.
 */
( function testCloneDoesNothingWithFunctions()
{
    var func = function() {},
        obj  = { foo: func };

    assert.ok( func === util.clone( obj, true ).foo,
        "Functions should not be cloned"
    );
} )();


/**
 * Primitives cannot be cloned, so we should expect that they are simply
 * returned
 */
( function testPrimitivesAreProperlyReturnedByClone()
{
    // we don't try NaN because NaN != NaN; we'll try it separately
    var prim = [ null, 1, true, false, undefined ],
        i    = prim.length;

    while ( i-- )
    {
        var val = prim[ i ];

        assert.equal( val, util.clone( val ),
            'Failed to clone primitive value: ' + val
        );
    }

    // test NaN separately
    assert.ok( isNaN( util.clone( NaN ) ) );
} )();