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jdisho
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freak4pc
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Implement UIScrollView.reachedBottom (#173)
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‎CHANGELOG.md

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Changelog
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=========
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- added `reachedBottom(offset:)` for `UIScrollView`
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5.0.0
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-----
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- Update to RxSwift 5.0.

‎Playground/RxSwiftExtPlayground.playground/Pages/Index.xcplaygroundpage/Contents.swift

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- [bufferWithTrigger()](bufferWithTrigger) Collects the elements of the source observable, and emits them as an array when the trigger emits.
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- **UIViewPropertyAnimator** [animate()](UIViewPropertyAnimator.animate) operator, returns a Completable that completes as soon as the animation ends.
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- **UIViewPropertyAnimator** [fractionComplete](UIViewPropertyAnimator.fractionComplete) binder, provides a reactive way to bind to `UIViewPropertyAnimator.fractionComplete`.
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- **UIScrollView** [reachedBottom](UIScrollView.reachedBottom) emits events when UIScrollView is scrolled to the bottom.
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*/
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//: [Next >>](@next)

‎Playground/RxSwiftExtPlayground.playground/Pages/UIScrollView.reachedBottom.xcplaygroundpage/Contents.swift

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/*:
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> # IMPORTANT: To use `RxSwiftExtPlayground.playground`, please:
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1. Make sure you have [Carthage](https://github.com/Carthage/Carthage) installed
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1. Fetch Carthage dependencies from shell: `carthage bootstrap --platform ios`
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1. Build scheme `RxSwiftExtPlayground` scheme for a simulator target
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1. Choose `View > Show Debug Area`
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*/
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//: [Previous](@previous)
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import RxSwift
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import RxCocoa
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import RxSwiftExt
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import PlaygroundSupport
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import UIKit
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/*:
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## reachedBottom
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The `reachedBottom` operator provides a sequence that emits every time the `UIScrollView` is scrolled to the bottom.
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Please open the Assistant Editor (⌘⌥⏎) to see the Interactive Live View example.
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*/
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final class ReachedBottomViewController: UITableViewController {
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private let dataSource = Array(stride(from: 0, to: 28, by: 1))
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private let identifier = "identifier"
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private let disposeBag = DisposeBag()
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override func viewDidLoad() {
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super.viewDidLoad()
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tableView.register(UITableViewCell.self, forCellReuseIdentifier: identifier)
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tableView.rx.reachedBottom(offset: 40)
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.subscribe { print("Reached bottom") }
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.disposed(by: disposeBag)
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}
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override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
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return dataSource.count
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}
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override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
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let cell = tableView.dequeueReusableCell(withIdentifier: identifier, for: indexPath)
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cell.textLabel?.text = "\(dataSource[indexPath.row])"
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return cell
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}
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}
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// Present the view controller in the Live View window
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PlaygroundPage.current.liveView = ReachedBottomViewController()
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//: [Next](@next)

‎Playground/RxSwiftExtPlayground.playground/contents.xcplayground

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<page name='UIViewPropertyAnimator.fractionComplete'/>
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<page name='withUnretained'/>
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</pages>
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</playground>
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</playground>

‎RxSwiftExt.xcodeproj/project.pbxproj

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780CB21D20A0EE8300FD3F39 /* MapManyTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 780CB21C20A0EE8300FD3F39 /* MapManyTests.swift */; };
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780CB21E20A0EE8300FD3F39 /* MapManyTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 780CB21C20A0EE8300FD3F39 /* MapManyTests.swift */; };
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780CB21F20A0EE8300FD3F39 /* MapManyTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 780CB21C20A0EE8300FD3F39 /* MapManyTests.swift */; };
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78199613228449CA00340AF4 /* UIScrollView+reachedBottom.swift in Sources */ = {isa = PBXBuildFile; fileRef = 78199612228449CA00340AF4 /* UIScrollView+reachedBottom.swift */; };
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1958B5F0216768D900CAF1D3 /* unwrap+SharedSequence.swift */,
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A23E148A21A9F03600CD5B2F /* partition+RxCocoa.swift */,
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78199612228449CA00340AF4 /* UIScrollView+reachedBottom.swift */,
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path = RxCocoa;
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sourceTree = "<group>";
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1A8741AB20745A91004BB762 /* UIViewPropertyAnimatorTests+Rx.swift */,
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1958B5F521676ECB00CAF1D3 /* unrwapTests+SharedSequence.swift */,
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A23E149221A9F73500CD5B2F /* PartitionTests+RxCocoa.swift */,
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7819961422844E9D00340AF4 /* UIScrollView+reachedBottomTests.swift */,
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);
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name = RxCocoa;
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path = Tests/RxCocoa;
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4A73956C206D501300E2BE2D /* UIViewPropertyAnimator+Rx.swift in Sources */,
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78199613228449CA00340AF4 /* UIScrollView+reachedBottom.swift in Sources */,
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538607B41E6F334B000361DE /* ObservableType+Weak.swift in Sources */,
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BF79DA0E206C185B008AA708 /* WithUnretainedTests.swift in Sources */,
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538607EE1E6F36A9000361DE /* WeakTests.swift in Sources */,
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7819961622844EF800340AF4 /* UIScrollView+reachedBottomTests.swift in Sources */,
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780CB21920A0ED3B00FD3F39 /* ToSortedArrayTests.swift in Sources */,
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538607E51E6F36A9000361DE /* IgnoreWhenTests.swift in Sources */,
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538607E11E6F36A9000361DE /* CatchErrorJustCompleteTests.swift in Sources */,

‎Source/RxCocoa/UIScrollView+reachedBottom.swift

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//
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// UIScrollView+reachedBottom.swift
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// RxSwiftExt
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//
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// Created by Anton Nazarov on 09/05/2019.
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// Copyright © 2019 RxSwift Community. All rights reserved.
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//
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import UIKit
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import RxSwift
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import RxCocoa
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public extension Reactive where Base: UIScrollView {
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/**
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Shows if the bottom of the UIScrollView is reached.
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- parameter offset: A threshhold indicating the bottom of the UIScrollView.
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- returns: ControlEvent that emits when the bottom of the base UIScrollView is reached.
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*/
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func reachedBottom(offset: CGFloat = 0.0) -> ControlEvent<Void> {
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let source = contentOffset.map { [base] contentOffset in
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let visibleHeight = base.frame.height - base.contentInset.top - base.contentInset.bottom
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let y = contentOffset.y + base.contentInset.top
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let threshold = max(offset, base.contentSize.height - visibleHeight)
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return y >= threshold
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}
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.distinctUntilChanged()
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.filter { $0 }
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.map { _ in () }
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return ControlEvent(events: source)
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}
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}

‎Tests/RxCocoa/UIScrollView+reachedBottomTests.swift

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//
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// UIScrollView+reachedBottomTests.swift
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// RxSwiftExt
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//
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// Created by Anton Nazarov on 09/05/2019.
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// Copyright © 2019 RxSwift Community. All rights reserved.
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//
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import XCTest
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import RxCocoa
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import RxSwift
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import RxTest
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import RxSwiftExt
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final class UIScrollViewReachedBottomTests: XCTestCase {
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private var tableView: UITableView!
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private var dataSource: StubDataSource!
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private var scheduler: TestScheduler!
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private var observer: TestableObserver<Void>!
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private var disposeBag: DisposeBag!
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override func setUp() {
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super.setUp()
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dataSource = StubDataSource()
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tableView = UITableView()
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tableView.dataSource = dataSource
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tableView.rowHeight = 44
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tableView.reloadData()
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scheduler = TestScheduler(initialClock: 0)
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observer = scheduler.createObserver(Void.self)
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disposeBag = DisposeBag()
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}
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override func tearDown() {
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dataSource = nil
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tableView = nil
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scheduler = nil
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observer = nil
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super.tearDown()
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}
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func testReachedBottomNotEmitsIfNotScrolledToBottom() {
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// Given
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let almostBottomY = CGFloat(dataSource.cellsCount) * tableView.rowHeight - 1
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tableView.rx.reachedBottom().bind(to: observer).disposed(by: disposeBag)
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// When
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tableView.contentOffset = CGPoint(x: 0, y: almostBottomY)
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// Then
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XCTAssertTrue(observer.events.isEmpty)
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}
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func testReachedBottomNotEmitsIfNotScrolledToBottomWithNonZeroOffset() {
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// Given
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let offset: CGFloat = 40.0
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let almostBottomY = CGFloat(dataSource.cellsCount) * tableView.rowHeight - offset - 1
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tableView.rx.reachedBottom(offset: offset).bind(to: observer).disposed(by: disposeBag)
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// When
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tableView.contentOffset = CGPoint(x: 0, y: almostBottomY)
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// Then
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XCTAssertTrue(observer.events.isEmpty)
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}
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func testReachedBottomEmitsIfScrolledToBottom() {
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// Given
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let actual: [Recorded<Event<Void>>] = [.next(0, ())]
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let bottomY = CGFloat(dataSource.cellsCount) * tableView.rowHeight
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tableView.rx.reachedBottom().bind(to: observer).disposed(by: disposeBag)
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// When
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tableView.contentOffset = CGPoint(x: 0, y: bottomY)
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// Then
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XCTAssertEqual(actual.count, observer.events.count)
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}
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}
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private extension UIScrollViewReachedBottomTests {
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final class StubDataSource: NSObject, UITableViewDataSource {
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let cellsCount = 28
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func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
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return cellsCount
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}
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func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
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return UITableViewCell()
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}
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}
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}

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