Added util.copyTo()
parent
e93a4db3e4
commit
4d0724b85d
58
lib/util.js
58
lib/util.js
|
@ -171,6 +171,64 @@ exports.clone = function clone( data, deep )
|
|||
};
|
||||
|
||||
|
||||
/**
|
||||
* Copies properties from one object to another
|
||||
*
|
||||
* This method is designed to support very basic object extensions. The
|
||||
* destination argument is first to allow extending an object without using the
|
||||
* full-blown class system.
|
||||
*
|
||||
* @param {Object} dest destination object
|
||||
* @param {Object} src source object
|
||||
*
|
||||
* @return {Object} dest
|
||||
*/
|
||||
exports.copyTo = function( dest, src )
|
||||
{
|
||||
var get, set, data;
|
||||
|
||||
// sanity check
|
||||
if ( !( dest instanceof Object ) || !( src instanceof Object ) )
|
||||
{
|
||||
throw TypeError(
|
||||
"Must provide both source and destination objects"
|
||||
);
|
||||
}
|
||||
|
||||
// slower; supports getters/setters
|
||||
if ( can_define_prop )
|
||||
{
|
||||
for ( prop in src )
|
||||
{
|
||||
data = Object.getOwnPropertyDescriptor( src, prop );
|
||||
|
||||
if ( data.get || data.set )
|
||||
{
|
||||
// define the property the slower way (only needed for
|
||||
// getters/setters)
|
||||
Object.defineProperty( dest, prop, data );
|
||||
}
|
||||
else
|
||||
{
|
||||
// normal copy by reference
|
||||
dest[ prop ] = src[ prop ];
|
||||
}
|
||||
}
|
||||
}
|
||||
// quick (keep if statement out of the loop)
|
||||
else
|
||||
{
|
||||
for ( prop in src )
|
||||
{
|
||||
dest[ prop ] = src[ prop ];
|
||||
}
|
||||
}
|
||||
|
||||
// return dest for convenience (and to feel useful about ourselves)
|
||||
return dest;
|
||||
};
|
||||
|
||||
|
||||
/**
|
||||
* Parses object properties to determine how they should be interpreted in an
|
||||
* Object Oriented manner
|
||||
|
|
|
@ -0,0 +1,144 @@
|
|||
/**
|
||||
* Tests util.copy
|
||||
*
|
||||
* Copyright (C) 2010 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 <http://www.gnu.org/licenses/>.
|
||||
*
|
||||
* @author Mike Gerwitz
|
||||
* @package test
|
||||
*/
|
||||
|
||||
var common = require( './common' ),
|
||||
assert = require( 'assert' ),
|
||||
util = common.require( 'util' ),
|
||||
|
||||
copyTo = util.copyTo,
|
||||
get_set = !( util.definePropertyFallback() )
|
||||
;
|
||||
|
||||
|
||||
/**
|
||||
* Just a basic copy test. Ensure the values are copied by reference.
|
||||
*/
|
||||
( function testCopiesReferencesToDestinationObject()
|
||||
{
|
||||
var src = {
|
||||
a: 'a',
|
||||
b: 2,
|
||||
c: true,
|
||||
d: false,
|
||||
e: undefined,
|
||||
d: null,
|
||||
f: function() {},
|
||||
},
|
||||
dest = {}
|
||||
;
|
||||
|
||||
copyTo( dest, src );
|
||||
|
||||
for ( key in src )
|
||||
{
|
||||
assert.deepEqual( src[ key ], dest[ key ],
|
||||
"Copies by reference by default"
|
||||
);
|
||||
}
|
||||
} )();
|
||||
|
||||
|
||||
/**
|
||||
* Same concept as above, but with getters/setters
|
||||
*/
|
||||
( function testGettersAndSettersAreCopiedByReferenceToDestinationObject()
|
||||
{
|
||||
// no use in performing the test if the engine doesn't support it
|
||||
if ( !get_set )
|
||||
{
|
||||
return;
|
||||
}
|
||||
|
||||
var get = function() {},
|
||||
set = function() {},
|
||||
src = {},
|
||||
dest = {},
|
||||
|
||||
result = null
|
||||
;
|
||||
|
||||
Object.defineProperty( src, 'foo', {
|
||||
get: get,
|
||||
set: set,
|
||||
|
||||
// so copy can actually see the property
|
||||
enumerable: true,
|
||||
} );
|
||||
|
||||
copyTo( dest, src );
|
||||
|
||||
// look up the getter/setter in dest
|
||||
result = Object.getOwnPropertyDescriptor( dest, 'foo' );
|
||||
|
||||
// check getter
|
||||
assert.deepEqual( result.get, get,
|
||||
"Getter is copied by reference by default"
|
||||
);
|
||||
|
||||
// check setter
|
||||
assert.deepEqual( result.set, set,
|
||||
"Setter is copied by reference by default"
|
||||
)
|
||||
} )();
|
||||
|
||||
|
||||
/**
|
||||
* For convenience
|
||||
*/
|
||||
( function testOperationReturnsDest()
|
||||
{
|
||||
var dest = {};
|
||||
|
||||
assert.deepEqual( copyTo( dest, {} ), dest,
|
||||
"Copy operation returns dest"
|
||||
);
|
||||
} )();
|
||||
|
||||
|
||||
/**
|
||||
* Just one of those tests you feel silly for making but is required
|
||||
*/
|
||||
( function testThrowsErrorIfSourceOrDestAreNotGiven()
|
||||
{
|
||||
assert.throws( function()
|
||||
{
|
||||
copyTo();
|
||||
}, TypeError, "Dest parameter is required" );
|
||||
|
||||
assert.throws( function()
|
||||
{
|
||||
copyTo( 'bla', {} );
|
||||
}, TypeError, "Dest parameter is required to be an object" );
|
||||
|
||||
assert.throws( function()
|
||||
{
|
||||
copyTo( {} );
|
||||
}, TypeError, "Src parameter is required" );
|
||||
|
||||
assert.throws( function()
|
||||
{
|
||||
copyTo( {}, 'foo' );
|
||||
}, TypeError, "Src parameter is required to be an object" );
|
||||
} )();
|
||||
|
Loading…
Reference in New Issue