Ordered insert using binary searching for angularJS

OrderedInsert.js

/**
 * @name orderedInsert
 * @param {Array} collection
 * @param {String} key
 * @param {Object | array} items - array of objects to insert
 * @returns {promise}
 * @description will insert an object into a sorted collection using a modified
 * form of binary searching. it will also insert an array of objects if that is provided
 * instead.
 * @example
 *
 * var arr = [{"id":1,"a":1},{"id":5,"a":2}];
 * var items = {"id":10,"a":3} or [{"id":10,"a":3}, {"id":10,"a":3}];
 *
 * lo.orderedInsert(arr, items, 'id').then(function (arr){
 *   arr                    //[{"id":1,"a":1},{"id":5,"a":2},{"id":10,"a":3}]
 * }, function (err){
 *    err
 * })
 */

var orderedInsert = function orderedInsert(collection, items, key) {
    var q = $q.defer();

    /**
     * @name insertObject
     * @param collection
     * @param item
     * @param key
     * @returns {promise}
     * @description insert object into sorted array
     */
    var insertObject = function insertObject(collection, item, key) {

        var a = $q.defer(),
            low = 0,                                    //low value of binary search
            high = collection.length - 1,               //high value of binary search
            i = null,                                   //mid point
            value = item[key],                          //value to compare to
            result = collection,                        //collection to return
            isValueNumber = (typeof value == 'number'); //true if value is number, false if not

        if (collection.length == 0) {                   //push and resolve if collection is 0
            result.push(item);
            a.resolve(result);
        } else {

            while (low <= high) {
                i = (low + high) / 2 | 0;               //bitwise to floor value
                var searchValue = (isValueNumber) ? parseFloat(result[i][key]) : result[i][key];
                if (searchValue < value) {
                    if (i + 1 > high) {                 //if potential low is greater than high, we cant loop again and item does not exist
                        result.splice(i + 1, 0, item);
                        a.resolve(result);
                    } else {
                        low = i + 1;                    //low is now midpoint +1, search upper half
                        continue
                    }

                } else if (searchValue > value) {
                    if (low > i - 1) {                   //if low is greater than potential high, we cant loop again and item does not exist
                        result.splice(i, 0, item);
                        a.resolve(result);
                    } else {
                        high = i - 1;
                        continue
                    }

                } else {
                    result.splice(i, 0, item);          //if item exists, splice to that index
                    a.resolve(result);
                }

                break;
            }
        }

        return a.promise;
    };

    /**
     *
     * @param collection
     * @param items
     * @param key
     * @returns {promise}
     * @description will loop through values in the items array and insert them
     */
    var insertArray = function insertArray(collection, items, key) {
        var a = $q.defer(),
            length = items.length,
            i = -1,
            result = collection;

        (function insertNext(){     //function calling instead of looping as we need to make sure it waits
            i++;                    //until object has been inserted
            if(i < length) {
                insertObject(result, items[i], key).then(function (arr) {
                    result = arr;
                    insertNext();
                })
            }else{
                a.resolve(result);
            }
        })();

        return a.promise;
    };


    if (angular.isArray(items)) {
        insertArray(collection, items, key).then(q.resolve);
    } else if (angular.isObject(items)) {
        insertObject(collection, items, key).then(q.resolve)
    } else {
        q.reject("items must be either an object or an array of objects");
    }

    return q.promise;
};