//
//  UITableView+RxTests.swift
//  Tests
//
//  Created by Krunoslav Zaher on 4/8/16.
//  Copyright © 2016 Krunoslav Zaher. All rights reserved.
//

import RxSwift
import RxCocoa
import XCTest

final class UITableViewTests : RxTest {
    func testTableView_DelegateEventCompletesOnDealloc() {
        let createView: () -> UITableView = { UITableView(frame: CGRect(x: 0, y: 0, width: 1, height: 1)) }

        ensureEventDeallocated(createView) { (view: UITableView) in view.rx.itemSelected }
        ensureEventDeallocated(createView) { (view: UITableView) in view.rx.itemDeselected }
        ensureEventDeallocated(createView) { (view: UITableView) in view.rx.itemAccessoryButtonTapped }
        ensureEventDeallocated(createView) { (view: UITableView) in view.rx.modelSelected(Int.self) }
        ensureEventDeallocated(createView) { (view: UITableView) in view.rx.itemDeleted }
        ensureEventDeallocated(createView) { (view: UITableView) in view.rx.itemMoved }
        ensureEventDeallocated(createView) { (view: UITableView) in view.rx.itemInserted }
        ensureEventDeallocated(createView) { (view: UITableView) in view.rx.modelSelected(Int.self) }
        ensureEventDeallocated(createView) { (view: UITableView) in view.rx.modelDeselected(Int.self) }
        ensureEventDeallocated(createView) { (view: UITableView) in view.rx.modelDeleted(Int.self) }
        ensureEventDeallocated(createView) { (view: UITableView) in view.rx.willDisplayCell }
        ensureEventDeallocated(createView) { (view: UITableView) in view.rx.didEndDisplayingCell }
    }

    func testTableView_itemSelected() {
        let tableView = UITableView(frame: CGRect(x: 0, y: 0, width: 1, height: 1))

        var resultIndexPath: IndexPath? = nil

        let subscription = tableView.rx.itemSelected
            .subscribe(onNext: { indexPath in
                resultIndexPath = indexPath
            })

        let testRow = IndexPath(row: 1, section: 0)
        tableView.delegate!.tableView!(tableView, didSelectRowAt: testRow)

        XCTAssertEqual(resultIndexPath, testRow)
        subscription.dispose()
    }

    func testTableView_itemDeselected() {
        let tableView = UITableView(frame: CGRect(x: 0, y: 0, width: 1, height: 1))

        var resultIndexPath: IndexPath? = nil

        let subscription = tableView.rx.itemDeselected
            .subscribe(onNext: { indexPath in
                resultIndexPath = indexPath
            })

        let testRow = IndexPath(row: 1, section: 0)
        tableView.delegate!.tableView!(tableView, didDeselectRowAt: testRow)

        XCTAssertEqual(resultIndexPath, testRow)
        subscription.dispose()
    }

    func testTableView_itemAccessoryButtonTapped() {
        let tableView = UITableView(frame: CGRect(x: 0, y: 0, width: 1, height: 1))

        var resultIndexPath: IndexPath? = nil

        let subscription = tableView.rx.itemAccessoryButtonTapped
            .subscribe(onNext: { indexPath in
                resultIndexPath = indexPath
            })

        let testRow = IndexPath(row: 1, section: 0)
        tableView.delegate!.tableView!(tableView, accessoryButtonTappedForRowWith: testRow)

        XCTAssertEqual(resultIndexPath, testRow)
        subscription.dispose()
    }

    func testTableView_itemDeleted() {
        let items: Observable<[Int]> = Observable.just([1, 2, 3])

        let createView: () -> (UITableView, Disposable) = {
            let tableView = UITableView(frame: CGRect(x: 0, y: 0, width: 1, height: 1))
            let dataSourceSubscription = items.bind(to: tableView.rx.items) { (tv, index: Int, item: Int) -> UITableViewCell in
                return UITableViewCell(style: .default, reuseIdentifier: "Identity")
            }

            return (tableView, dataSourceSubscription)
        }
        
        let (tableView, dataSourceSubscription) = createView()

        var resultIndexPath: IndexPath? = nil

        let subscription = tableView.rx.itemDeleted
            .subscribe(onNext: { indexPath in
                resultIndexPath = indexPath
            })

        let testRow = IndexPath(row: 1, section: 0)
        tableView.dataSource!.tableView!(tableView, commit: .delete, forRowAt:  testRow)

        XCTAssertEqual(resultIndexPath, testRow)
        subscription.dispose()
        dataSourceSubscription.dispose()
    }

    func testTableView_itemInserted() {
        let items: Observable<[Int]> = Observable.just([1, 2, 3])

        let createView: () -> (UITableView, Disposable) = {
            let tableView = UITableView(frame: CGRect(x: 0, y: 0, width: 1, height: 1))
            let dataSourceSubscription = items.bind(to: tableView.rx.items) { (tv, index: Int, item: Int) -> UITableViewCell in
                return UITableViewCell(style: .default, reuseIdentifier: "Identity")
            }

            return (tableView, dataSourceSubscription)
        }

        let (tableView, dataSourceSubscription) = createView()

        var resultIndexPath: IndexPath? = nil

        let subscription = tableView.rx.itemInserted
            .subscribe(onNext: { indexPath in
                resultIndexPath = indexPath
            })

        let testRow = IndexPath(row: 1, section: 0)
        tableView.dataSource!.tableView!(tableView, commit: .insert, forRowAt:  testRow)

        XCTAssertEqual(resultIndexPath, testRow)
        subscription.dispose()
        dataSourceSubscription.dispose()
    }

    func testTableView_willDisplayCell() {
        let tableView = UITableView(frame: CGRect(x: 0, y: 0, width: 1, height: 1))

        var resultIndexPath: IndexPath? = nil
        var resultCell: UITableViewCell? = nil

        let subscription = tableView.rx.willDisplayCell
            .subscribe(onNext: { (cell, indexPath) in
                resultIndexPath = indexPath
                resultCell = cell
            })

        let testRow = IndexPath(row: 1, section: 0)
        let testCell = UITableViewCell()
        tableView.delegate!.tableView!(tableView, willDisplay: testCell, forRowAt: testRow)

        XCTAssertEqual(resultIndexPath, testRow)
        XCTAssertEqual(resultCell, testCell)
        subscription.dispose()
    }

    func testTableView_didEndDisplayingCell() {
        let tableView = UITableView(frame: CGRect(x: 0, y: 0, width: 1, height: 1))

        var resultIndexPath: IndexPath? = nil
        var resultCell: UITableViewCell? = nil

        let subscription = tableView.rx.didEndDisplayingCell
            .subscribe(onNext: { (cell, indexPath) in
                resultIndexPath = indexPath
                resultCell = cell
            })

        let testRow = IndexPath(row: 1, section: 0)
        let testCell = UITableViewCell()
        tableView.delegate!.tableView!(tableView, didEndDisplaying: testCell, forRowAt: testRow)

        XCTAssertEqual(resultIndexPath, testRow)
        XCTAssertEqual(resultCell, testCell)
        subscription.dispose()
    }

    func testTableView_itemMoved() {
        let items: Observable<[Int]> = Observable.just([1, 2, 3])

        let createView: () -> (UITableView, Disposable) = {
            let tableView = UITableView(frame: CGRect(x: 0, y: 0, width: 1, height: 1))
            let dataSourceSubscription = items.bind(to: tableView.rx.items) { (tv, index: Int, item: Int) -> UITableViewCell in
                return UITableViewCell(style: .default, reuseIdentifier: "Identity")
            }

            return (tableView, dataSourceSubscription)
        }

        let (tableView, dataSourceSubscription) = createView()

        var resultIndexPath: IndexPath? = nil
        var resultIndexPath2: IndexPath? = nil

        let subscription = tableView.rx.itemMoved
            .subscribe(onNext: { (indexPath, indexPath2) in
                resultIndexPath = indexPath
                resultIndexPath2 = indexPath2
            })

        let testRow = IndexPath(row: 1, section: 0)
        let testRow2 = IndexPath(row: 1, section: 0)
        tableView.dataSource!.tableView!(tableView, moveRowAt: testRow, to: testRow2)

        XCTAssertEqual(resultIndexPath, testRow)
        XCTAssertEqual(resultIndexPath2, testRow2)
        subscription.dispose()
        dataSourceSubscription.dispose()
    }

    func testTableView_DelegateEventCompletesOnDealloc1() {
        let items: Observable<[Int]> = Observable.just([1, 2, 3])

        let createView: () -> (UITableView, Disposable) = {
            let tableView = UITableView(frame: CGRect(x: 0, y: 0, width: 1, height: 1))
            let dataSourceSubscription = items.bind(to: tableView.rx.items) { (tv, index: Int, item: Int) -> UITableViewCell in
                return UITableViewCell(style: .default, reuseIdentifier: "Identity")
            }

            return (tableView, dataSourceSubscription)
        }
        ensureEventDeallocated(createView) { (view: UITableView) in view.rx.modelSelected(Int.self) }
    }

    func testTableView_DelegateEventCompletesOnDealloc2() {
        let items: Observable<[Int]> = Observable.just([1, 2, 3])

        let createView: () -> (UITableView, Disposable) = {
            let tableView = UITableView(frame: CGRect(x: 0, y: 0, width: 1, height: 1))
            tableView.register(NSClassFromString("UITableViewCell"), forCellReuseIdentifier: "a")
            let dataSourceSubscription = items.bind(to: tableView.rx.items(cellIdentifier: "a")) { (index: Int, item: Int, cell) in

            }

            return (tableView, dataSourceSubscription)
        }
        ensureEventDeallocated(createView) { (view: UITableView) in view.rx.modelSelected(Int.self) }
    }

    func testTableView_DelegateEventCompletesOnDealloc2_cellType() {
        let items: Observable<[Int]> = Observable.just([1, 2, 3])

        let createView: () -> (UITableView, Disposable) = {
            let tableView = UITableView(frame: CGRect(x: 0, y: 0, width: 1, height: 1))
            tableView.register(NSClassFromString("UITableViewCell"), forCellReuseIdentifier: "a")
            let dataSourceSubscription = items.bind(to: tableView.rx.items(cellIdentifier: "a", cellType: UITableViewCell.self)) { (index: Int, item: Int, cell) in

            }

            return (tableView, dataSourceSubscription)
        }
        ensureEventDeallocated(createView) { (view: UITableView) in view.rx.modelSelected(Int.self) }
    }

    func testTableView_ModelSelected_rx_itemsWithCellFactory() {
        let items: Observable<[Int]> = Observable.just([1, 2, 3])
        
        let createView: () -> (UITableView, Disposable) = {
            let tableView = UITableView(frame: CGRect(x: 0, y: 0, width: 1, height: 1))
            let dataSourceSubscription = items.bind(to: tableView.rx.items) { (tv, index: Int, item: Int) -> UITableViewCell in
                return UITableViewCell(style: .default, reuseIdentifier: "Identity")
            }
            
            return (tableView, dataSourceSubscription)
        }
        
        let (tableView, dataSourceSubscription) = createView()
        
        var selectedItem: Int? = nil
        
        let s = tableView.rx.modelSelected(Int.self)
            .subscribe(onNext: { item in
                selectedItem = item
            })
        
        tableView.delegate!.tableView!(tableView, didSelectRowAt: IndexPath(row: 1, section: 0))
        
        XCTAssertEqual(selectedItem, 2)
        
        dataSourceSubscription.dispose()
        s.dispose()
    }

    func testTableView_ModelSelected_itemsWithCellIdentifier() {
        let items: Observable<[Int]> = Observable.just([1, 2, 3])

        let createView: () -> (UITableView, Disposable) = {
            let tableView = UITableView(frame: CGRect(x: 0, y: 0, width: 1, height: 1))
            tableView.register(NSClassFromString("UITableViewCell"), forCellReuseIdentifier: "a")
            let dataSourceSubscription = items.bind(to: tableView.rx.items(cellIdentifier: "a")) { (index: Int, item: Int, cell) in

            }

            return (tableView, dataSourceSubscription)
        }

        let (tableView, dataSourceSubscription) = createView()

        var selectedItem: Int? = nil

        let s = tableView.rx.modelSelected(Int.self)
            .subscribe(onNext: { item in
                selectedItem = item
            })

        tableView.delegate!.tableView!(tableView, didSelectRowAt: IndexPath(row: 1, section: 0))

        XCTAssertEqual(selectedItem, 2)

        dataSourceSubscription.dispose()
        s.dispose()
    }

    func testTableView_ModelDeselected_rx_itemsWithCellFactory() {
        let items: Observable<[Int]> = Observable.just([1, 2, 3])

        let createView: () -> (UITableView, Disposable) = {
            let tableView = UITableView(frame: CGRect(x: 0, y: 0, width: 1, height: 1))
            let dataSourceSubscription = items.bind(to: tableView.rx.items) { (tv, index: Int, item: Int) -> UITableViewCell in
                return UITableViewCell(style: .default, reuseIdentifier: "Identity")
            }

            return (tableView, dataSourceSubscription)
        }

        let (tableView, dataSourceSubscription) = createView()

        var selectedItem: Int? = nil

        let s = tableView.rx.modelDeselected(Int.self)
            .subscribe(onNext: { item in
                selectedItem = item
            })

        tableView.delegate!.tableView!(tableView, didDeselectRowAt: IndexPath(row: 1, section: 0))

        XCTAssertEqual(selectedItem, 2)

        dataSourceSubscription.dispose()
        s.dispose()
    }
    
    func testTableView_ModelDeleted_rx_itemsWithCellFactory() {
        let items: Observable<[Int]> = Observable.just([1, 2, 3])
        
        let createView: () -> (UITableView, Disposable) = {
            let tableView = UITableView(frame: CGRect(x: 0, y: 0, width: 1, height: 1))
            let dataSourceSubscription = items.bind(to: tableView.rx.items) { (tv, index: Int, item: Int) -> UITableViewCell in
                return UITableViewCell(style: .default, reuseIdentifier: "Identity")
            }
            
            return (tableView, dataSourceSubscription)
        }
        
        let (tableView, dataSourceSubscription) = createView()
        
        var deletedItem: Int? = nil
        
        let s = tableView.rx.modelDeleted(Int.self)
            .subscribe(onNext: { item in
                deletedItem = item
            })
        
        tableView.dataSource?.tableView!(tableView, commit: .delete, forRowAt: IndexPath(row: 1, section: 0))
        
        XCTAssertEqual(deletedItem, 2)
        
        dataSourceSubscription.dispose()
        s.dispose()
    }

    func testTableView_ModelDeselected_itemsWithCellIdentifier() {
        let items: Observable<[Int]> = Observable.just([1, 2, 3])

        let createView: () -> (UITableView, Disposable) = {
            let tableView = UITableView(frame: CGRect(x: 0, y: 0, width: 1, height: 1))
            tableView.register(NSClassFromString("UITableViewCell"), forCellReuseIdentifier: "a")
            let dataSourceSubscription = items.bind(to: tableView.rx.items(cellIdentifier: "a")) { (index: Int, item: Int, cell) in

            }

            return (tableView, dataSourceSubscription)
        }

        let (tableView, dataSourceSubscription) = createView()

        var selectedItem: Int? = nil

        let s = tableView.rx.modelDeselected(Int.self)
            .subscribe(onNext: { item in
                selectedItem = item
            })

        tableView.delegate!.tableView!(tableView, didDeselectRowAt: IndexPath(row: 1, section: 0))
        
        XCTAssertEqual(selectedItem, 2)
        
        dataSourceSubscription.dispose()
        s.dispose()
    }

    func testTableView_modelAtIndexPath_normal() {
        let items: Observable<[Int]> = Observable.just([1, 2, 3])

        let createView: () -> (UITableView, Disposable) = {
            let tableView = UITableView(frame: CGRect(x: 0, y: 0, width: 1, height: 1))
            tableView.register(NSClassFromString("UITableViewCell"), forCellReuseIdentifier: "a")
            let dataSource = SectionedViewDataSourceMock()
            let dataSourceSubscription = items.bind(to: tableView.rx.items(dataSource: dataSource))

            return (tableView, dataSourceSubscription)
        }

        let (tableView, dataSourceSubscription) = createView()

        let model: Int = try! tableView.rx.model(at: IndexPath(item: 1, section: 0))

        XCTAssertEqual(model, 2)
        
        dataSourceSubscription.dispose()
    }
}

extension UITableViewTests {
    func testDataSourceIsBeingRetainedUntilDispose() {

        var dataSourceDeallocated = false

        var outerTableView: UITableView? = nil
        outerTableView?.beginUpdates()

        var dataSourceSubscription: Disposable!
        autoreleasepool {
            let items: Observable<[Int]> = Observable.just([1, 2, 3])
            let dataSource = SectionedViewDataSourceMock()
            let tableView = UITableView(frame: CGRect(x: 0, y: 0, width: 1, height: 1))
            outerTableView = tableView
            dataSourceSubscription = items.bind(to: tableView.rx.items(dataSource: dataSource))

            _ = dataSource.rx.deallocated.subscribe(onNext: { _ in
                dataSourceDeallocated = true
            })
        }
        XCTAssert(dataSourceDeallocated == false)
        autoreleasepool { dataSourceSubscription.dispose() }
        XCTAssert(dataSourceDeallocated == true)
    }

    func testDataSourceIsBeingRetainedUntilTableViewDealloc() {

        var dataSourceDeallocated = false

        autoreleasepool {
            let tableView = UITableView(frame: CGRect(x: 0, y: 0, width: 1, height: 1))
            tableView.register(UITableViewCell.self, forCellReuseIdentifier: "a")

            let items: Observable<[Int]> = Observable.just([1, 2, 3])
            let dataSource = SectionedViewDataSourceMock()
            _ = items.bind(to: tableView.rx.items(dataSource: dataSource))

            _ = dataSource.rx.deallocated.subscribe(onNext: { _ in
                dataSourceDeallocated = true
            })

            XCTAssert(dataSourceDeallocated == false)
        }
        XCTAssert(dataSourceDeallocated == true)
    }

    func testSetDataSourceUsesWeakReference() {

        var dataSourceDeallocated = false

        let tableView = UITableView(frame: CGRect(x: 0, y: 0, width: 1, height: 1))
        tableView.register(UITableViewCell.self, forCellReuseIdentifier: "a")

        autoreleasepool {
            let dataSource = SectionedViewDataSourceMock()
            _ = tableView.rx.setDataSource(dataSource)

            _ = dataSource.rx.deallocated.subscribe(onNext: { _ in
                dataSourceDeallocated = true
            })

            XCTAssert(dataSourceDeallocated == false)
        }
        XCTAssert(dataSourceDeallocated == true)
    }

    func testTableViewDataSourceIsResetOnDispose() {
        var disposeEvents: [String] = []

        let items: Observable<[Int]> = Observable.just([1, 2, 3]).concat(Observable.never())
            .do(onDispose: {
                disposeEvents.append("disposed")
            })

        let createView: () -> (UITableView, Disposable) = {
            let tableView = UITableView(frame: CGRect(x: 0, y: 0, width: 1, height: 1))
            tableView.register(NSClassFromString("UITableViewCell"), forCellReuseIdentifier: "a")
            let dataSource = SectionedViewDataSourceMock()
            let dataSourceSubscription = items.bind(to: tableView.rx.items(dataSource: dataSource))

            return (tableView, dataSourceSubscription)
        }


        let (tableView, dataSourceSubscription) = createView()

        XCTAssertTrue(tableView.dataSource === RxTableViewDataSourceProxy.proxyForObject(tableView))

        _ = tableView.rx.sentMessage(#selector(UITableView.layoutIfNeeded)).subscribe(onNext: { _ in
            disposeEvents.append("layoutIfNeeded")
        })
        _ = tableView.rx.sentMessage(NSSelectorFromString("setDataSource:")).subscribe(onNext: { arguments in
            let isNull = NSNull().isEqual(arguments[0])
            disposeEvents.append("setDataSource:\(isNull ? "nil" : "nn")")
        })

        XCTAssertEqual(disposeEvents, [])
        dataSourceSubscription.dispose()
        XCTAssertEqual(disposeEvents, ["disposed", "layoutIfNeeded", "setDataSource:nil", "setDataSource:nn"])

        XCTAssertTrue(tableView.dataSource === tableView.rx.dataSource)
    }
}

// test #selector(UITableViewDataSource.tableView(_:commit:forRowAt:)
// https://github.com/ReactiveX/RxSwift/issues/907
extension UITableViewTests {
    func testDataSource_commitForRowAt_sentMessage() {
        let tableView = UITableView(frame: CGRect(x: 0, y: 0, width: 1, height: 1))
        tableView.register(UITableViewCell.self, forCellReuseIdentifier: "a")

        let dataSource = SectionedViewDataSourceMock()
        _ = tableView.rx.setDataSource(dataSource)

        var setDataSources: [UITableViewDataSource?] = []

        _ = tableView.rx.observeWeakly(UITableViewDataSource.self, "dataSource")
            .subscribe(onNext: { dataSource in
                setDataSources.append(dataSource)
            })

        XCTAssertFalse(tableView.dataSource!.responds(to: #selector(UITableViewDataSource.tableView(_:commit:forRowAt:))))

        let commitedEvents = tableView.rx.dataSource.sentMessage(#selector(UITableViewDataSource.tableView(_:commit:forRowAt:)))

        XCTAssertFalse(tableView.dataSource!.responds(to: #selector(UITableViewDataSource.tableView(_:commit:forRowAt:))))
        XCTAssertArraysEqual(setDataSources, [tableView.dataSource!] as [UITableViewDataSource?]) { $0 === $1 }

        var firstEvents: [Arguments] = []
        var secondEvents: [Arguments] = []

        let subscription1 = commitedEvents.subscribe(onNext: { event in
            firstEvents.append(Arguments(values: event))
        })

        XCTAssertTrue(tableView.dataSource!.responds(to: #selector(UITableViewDataSource.tableView(_:commit:forRowAt:))))
        XCTAssertArraysEqual(setDataSources, [tableView.dataSource, nil, tableView.dataSource] as [UITableViewDataSource?]) { $0 === $1 }

        let subscription2 = commitedEvents.subscribe(onNext: { event in
            secondEvents.append(Arguments(values: event))
        })

        XCTAssertTrue(tableView.dataSource!.responds(to: #selector(UITableViewDataSource.tableView(_:commit:forRowAt:))))
        XCTAssertArraysEqual(setDataSources, [tableView.dataSource, nil, tableView.dataSource] as [UITableViewDataSource?]) { $0 === $1 }

        let deleteEditingStyle: NSNumber = NSNumber(value: UITableViewCellEditingStyle.delete.rawValue)
        let indexPath: NSIndexPath = NSIndexPath(item: 0, section: 0)
        XCTAssertEqual(firstEvents, [] as [Arguments]) { $0 == $1 }
        XCTAssertEqual(secondEvents, [] as [Arguments]) { $0 == $1 }
        tableView.dataSource!.tableView!(tableView, commit: .delete, forRowAt: indexPath as IndexPath)
        XCTAssertEqual(firstEvents, [Arguments(values: [tableView, deleteEditingStyle, indexPath])] as [Arguments]) { $0 == $1 }
        XCTAssertEqual(secondEvents, [Arguments(values: [tableView, deleteEditingStyle, indexPath])] as [Arguments]) { $0 == $1 }

        subscription1.dispose()

        XCTAssertTrue(tableView.dataSource!.responds(to: #selector(UITableViewDataSource.tableView(_:commit:forRowAt:))))
        XCTAssertArraysEqual(setDataSources, [tableView.dataSource, nil, tableView.dataSource] as [UITableViewDataSource?]) { $0 === $1 }

        subscription2.dispose()

        XCTAssertFalse(tableView.dataSource!.responds(to: #selector(UITableViewDataSource.tableView(_:commit:forRowAt:))))
        XCTAssertArraysEqual(setDataSources, [tableView.dataSource, nil, tableView.dataSource, nil, tableView.dataSource]) { $0 === $1 }
    }

    func testDataSource_commitForRowAt_methodInvoked() {
        let tableView = UITableView(frame: CGRect(x: 0, y: 0, width: 1, height: 1))
        tableView.register(UITableViewCell.self, forCellReuseIdentifier: "a")

        let dataSource = SectionedViewDataSourceMock()
        _ = tableView.rx.setDataSource(dataSource)

        var setDataSources: [UITableViewDataSource?] = []

        _ = tableView.rx.observeWeakly(UITableViewDataSource.self, "dataSource")
            .subscribe(onNext: { dataSource in
                setDataSources.append(dataSource)
            })

        XCTAssertFalse(tableView.dataSource!.responds(to: #selector(UITableViewDataSource.tableView(_:commit:forRowAt:))))

        let commitedEvents = tableView.rx.dataSource.methodInvoked(#selector(UITableViewDataSource.tableView(_:commit:forRowAt:)))

        XCTAssertFalse(tableView.dataSource!.responds(to: #selector(UITableViewDataSource.tableView(_:commit:forRowAt:))))
        XCTAssertArraysEqual(setDataSources, [tableView.dataSource!] as [UITableViewDataSource?]) { $0 === $1 }

        var firstEvents: [Arguments] = []
        var secondEvents: [Arguments] = []

        let subscription1 = commitedEvents.subscribe(onNext: { event in
            firstEvents.append(Arguments(values: event))
        })

        XCTAssertTrue(tableView.dataSource!.responds(to: #selector(UITableViewDataSource.tableView(_:commit:forRowAt:))))
        XCTAssertArraysEqual(setDataSources, [tableView.dataSource, nil, tableView.dataSource] as [UITableViewDataSource?]) { $0 === $1 }

        let subscription2 = commitedEvents.subscribe(onNext: { event in
            secondEvents.append(Arguments(values: event))
        })

        XCTAssertTrue(tableView.dataSource!.responds(to: #selector(UITableViewDataSource.tableView(_:commit:forRowAt:))))
        XCTAssertArraysEqual(setDataSources, [tableView.dataSource, nil, tableView.dataSource] as [UITableViewDataSource?]) { $0 === $1 }

        let deleteEditingStyle: NSNumber = NSNumber(value: UITableViewCellEditingStyle.delete.rawValue)
        let indexPath: NSIndexPath = NSIndexPath(item: 0, section: 0)
        XCTAssertEqual(firstEvents, [] as [Arguments]) { $0 == $1 }
        XCTAssertEqual(secondEvents, [] as [Arguments]) { $0 == $1 }
        tableView.dataSource!.tableView!(tableView, commit: .delete, forRowAt: indexPath as IndexPath)
        XCTAssertEqual(firstEvents, [Arguments(values: [tableView, deleteEditingStyle, indexPath])] as [Arguments]) { $0 == $1 }
        XCTAssertEqual(secondEvents, [Arguments(values: [tableView, deleteEditingStyle, indexPath])] as [Arguments]) { $0 == $1 }

        subscription1.dispose()

        XCTAssertTrue(tableView.dataSource!.responds(to: #selector(UITableViewDataSource.tableView(_:commit:forRowAt:))))
        XCTAssertArraysEqual(setDataSources, [tableView.dataSource, nil, tableView.dataSource] as [UITableViewDataSource?]) { $0 === $1 }

        subscription2.dispose()

        XCTAssertFalse(tableView.dataSource!.responds(to: #selector(UITableViewDataSource.tableView(_:commit:forRowAt:))))
        XCTAssertArraysEqual(setDataSources, [tableView.dataSource, nil, tableView.dataSource, nil, tableView.dataSource]) { $0 === $1 }
    }


    func testDataSource_commitForRowAt_respondsWhenDataSourceImplementsCommitForRowAt() {
        let tableView = UITableView(frame: CGRect(x: 0, y: 0, width: 1, height: 1))
        tableView.register(UITableViewCell.self, forCellReuseIdentifier: "a")

        let dataSource = TableViewDataSourceThatImplementsCommitForRowAt()
        _ = tableView.rx.setDataSource(dataSource)

        XCTAssertTrue((tableView.dataSource!).responds(to: #selector(UITableViewDataSource.tableView(_:commit:forRowAt:))))
    }
}

@objc final class TableViewDataSourceThatImplementsCommitForRowAt: NSObject, UITableViewDataSource {
    func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCellEditingStyle, forRowAt indexPath: IndexPath) {
        arc4random_stir()
    }

    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return 0
    }

    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        return UITableViewCell()
    }
}
