keys.js•2.11 kB
var _curry1 = require('./internal/_curry1');
var _has = require('./internal/_has');
var _isArguments = require('./internal/_isArguments');
/**
* Returns a list containing the names of all the enumerable own properties of
* the supplied object.
* Note that the order of the output array is not guaranteed to be consistent
* across different JS platforms.
*
* @func
* @memberOf R
* @since v0.1.0
* @category Object
* @sig {k: v} -> [k]
* @param {Object} obj The object to extract properties from
* @return {Array} An array of the object's own properties.
* @example
*
* R.keys({a: 1, b: 2, c: 3}); //=> ['a', 'b', 'c']
*/
module.exports = (function() {
// cover IE < 9 keys issues
var hasEnumBug = !({toString: null}).propertyIsEnumerable('toString');
var nonEnumerableProps = ['constructor', 'valueOf', 'isPrototypeOf', 'toString',
'propertyIsEnumerable', 'hasOwnProperty', 'toLocaleString'];
// Safari bug
var hasArgsEnumBug = (function() {
'use strict';
return arguments.propertyIsEnumerable('length');
}());
var contains = function contains(list, item) {
var idx = 0;
while (idx < list.length) {
if (list[idx] === item) {
return true;
}
idx += 1;
}
return false;
};
return typeof Object.keys === 'function' && !hasArgsEnumBug ?
_curry1(function keys(obj) {
return Object(obj) !== obj ? [] : Object.keys(obj);
}) :
_curry1(function keys(obj) {
if (Object(obj) !== obj) {
return [];
}
var prop, nIdx;
var ks = [];
var checkArgsLength = hasArgsEnumBug && _isArguments(obj);
for (prop in obj) {
if (_has(prop, obj) && (!checkArgsLength || prop !== 'length')) {
ks[ks.length] = prop;
}
}
if (hasEnumBug) {
nIdx = nonEnumerableProps.length - 1;
while (nIdx >= 0) {
prop = nonEnumerableProps[nIdx];
if (_has(prop, obj) && !contains(ks, prop)) {
ks[ks.length] = prop;
}
nIdx -= 1;
}
}
return ks;
});
}());