RealmORM, realm.io ORM in Swift 2.0 with simple CoreData like NSFetchController features, sorting Results<object> by a key

RealmORM.swift

//
//  RealmORM.swift
//
//  Copyright © 2016 Mobile Flow LLC. All rights reserved.
//

import UIKit
import Realm
import RealmSwift

class RealORMFetchObject {
    
    
    var sections = Dictionary<String, Array<RealmORM>>()
    var sortedSections = [String]()

    let managedObjectContext : NSObject? = nil
    let fetchRequest : NSObject? = nil
    
    init() {
        
    }
    
    func reset() {
        self.sections.removeAll(keepCapacity: true)
        self.sortedSections.removeAll(keepCapacity: true)
    }
    
    func fetchResultsBySection(realm: Realm, sectionKey: String, classObject: RealmORM.Type) -> Int {
        self.reset()
        
        let objects = classObject.fetchAll(realm)
        for item in objects {
            // NOTE: assumes section key type of String, need to refactor for NSDate, Int64, etc.
            let value :String = (item.valueForKey(sectionKey) ?? "") as! String
            if self.sections.indexForKey(value) == nil {
                self.sections[value] = [item]
            }
            else {
                self.sections[value]?.append(item)
            }
        }
        self.sortedSections = Array(self.sections.keys).sort{ $0 < $1 }
        
        return self.sortedSections.count
    }
    
    func objectAtIndexPath(indexPath :NSIndexPath) -> RealmORM? {
        guard sortedSections.count > indexPath.section else { return nil }

        let tableSection = sections[sortedSections[indexPath.section]]
        
        guard tableSection != nil && tableSection!.count > 0 else { return nil }

        let tableItem = tableSection![indexPath.row]
        return tableItem
    }
    
    func numberOfRowsInSection(section :Int) -> Int {
        guard sortedSections.count > section else { return 0 }
        guard sections.count > 0 else { return 0 }
        
        return sections[sortedSections[section]]?.count ?? 0
    }
}

class RealmORM: Object {

    dynamic var uuid :String = NSUUID().UUIDString
    dynamic var createdAt = NSDate()

    func save(realm: Realm) {
        try! realm.write {
            realm.add(self)
        }

    }
    
    class func fetchAll(realm: Realm) -> Results<RealmORM> {
        return realm.objects(self).sorted("createdAt", ascending: true)
    }
    
}

   func testFetchObject() {

        // Testing RealORMFetchObject

        let realm = try! Realm()

        let testClass1 = testClass()
        testClass1.cat = "CATEGORY1"
        testClass1.save(realm)
        let testClass2 = testClass()
        testClass2.cat = "CATEGORY2"
        testClass2.save(realm)
        let testClass3 = testClass()
        testClass3. cat = "CATEGORY2"
        testClass3.save(realm)

        let fetchController = RealORMFetchObject()

        let sections = fetchController.sections

        XCTAssertEqual(sections.count, 0, "sections count should be zero initially")

        let rows = fetchController.numberOfRowsInSection(0)

        XCTAssertEqual(rows, 0, "rows should be zero initially")

        let object = fetchController.objectAtIndexPath(NSIndexPath(forItem: 0, inSection: 0))

        XCTAssertNil(object, "object should not exist initially")

        let fetchResult = fetchController.fetchResultsBySection(realm, sectionKey: "cat", classObject: testClass.self)

        let sections2 = fetchController.sections

        XCTAssertEqual(sections2.count, fetchResult, "sections count not equal")

        let rows1 = fetchController.numberOfRowsInSection(0)
        XCTAssertEqual(rows1, 1, "first section should equal 1")

        let rows2 = fetchController.numberOfRowsInSection(1)
        XCTAssertEqual(rows2, 2, "first section should equal 1")

        let object2 = fetchController.objectAtIndexPath(NSIndexPath(forItem: 0, inSection: 1))

        XCTAssertNotNil(object2, "object should not exist initially")



    }
`