Our unit test practices

unitTestingPractices.swift

//
//  HomeModuleTests.swift
//  AppName
//
//  Created by Musa Kokcen on 25.06.2021.
//  Copyright © 2021 AppName. All rights reserved.
//

@testable import TargetName_Debug
import XCTest

class HomeModuleTests: XCTestCase {
    var presenter: HomePresenter!
    var mockRouter: MockHomeRouter!
    var mockInteractor: MockHomeInteractor!
    var mockView: MockHomeView!
    
    static var homeData: HomeDataModel?

    override class func setUp() {
        super.setUp()
        let semaphore = DispatchSemaphore(value: 0)
        
        var error: Error?
        
        LocalJsonLoader.shared.read(for: HomeDataModel.self, withName: "homeData") { (result) in
            switch result {
            case .success(let data):
                HomeModuleTests.homeData = data
            case .failure(let err):
                error = err
            }
            semaphore.signal()
        }
        
        semaphore.wait()
        
        XCTAssertNil(error)
    }
    
    override func setUpWithError() throws  {
        
        let homeData = try XCTUnwrap(HomeModuleTests.homeData)
        
        mockRouter = MockHomeRouter()
        mockInteractor = MockHomeInteractor()
        mockView = MockHomeView()
        presenter = HomePresenter(router: mockRouter, interactor: mockInteractor, view: mockView, data: homeData)
    }
    
    func test_viewDidLoad_success() {
        XCTAssertFalse(mockView.isPrepareUICalled)

        presenter.viewDidLoad()
        
        XCTAssertTrue(mockView.isPrepareUICalled)
    }
    
    func test_numberOfRowsInTableView_success() throws {
        let numberOfData = try XCTUnwrap(HomeModuleTests.homeData?.data.count)
        
        presenter.prepareTableView()
        
        XCTAssertEqual(presenter.numberOfRowsInTableView(), numberOfData)
    }
    
    func test_didSelectRow_success() throws {
        let homeData = try XCTUnwrap(HomeModuleTests.homeData)
        
        let randomStep = Int.random(in: 0..<homeData.data.count)
        
        XCTAssertEqual(presenter.selectedRow(for: IndexPath(item: randomStep, section: 0)), homeData.data[randomStep])
    }
}