32 lines
745 B
JavaScript
32 lines
745 B
JavaScript
'use strict';
|
|
|
|
var nestedValue = require('../helpers/nestedValue');
|
|
|
|
var _require = require('../helpers/is'),
|
|
isFunction = _require.isFunction;
|
|
|
|
module.exports = function groupBy(key) {
|
|
var _this = this;
|
|
|
|
var collection = {};
|
|
|
|
this.items.forEach(function (item, index) {
|
|
var resolvedKey = void 0;
|
|
|
|
if (isFunction(key)) {
|
|
resolvedKey = key(item, index);
|
|
} else if (nestedValue(item, key) || nestedValue(item, key) === 0) {
|
|
resolvedKey = nestedValue(item, key);
|
|
} else {
|
|
resolvedKey = '';
|
|
}
|
|
|
|
if (collection[resolvedKey] === undefined) {
|
|
collection[resolvedKey] = new _this.constructor([]);
|
|
}
|
|
|
|
collection[resolvedKey].push(item);
|
|
});
|
|
|
|
return new this.constructor(collection);
|
|
}; |