RepositoryListViewModelTests.swift

func test_SelectRepository_EmitsShowRepository() {
    let repositoryToSelect = RepositoryViewModel(repository: testRepository)
    // Create fake observable which fires at 300
    let selectRepositoryObservable = testScheduler.createHotObservable([next(300, repositoryToSelect)])

    // Bind fake observable to the input
    selectRepositoryObservable
        .bind(to: viewModel.selectRepository)
        .disposed(by: disposeBag)

    // Subscribe on the showRepository output and start testScheduler
    let result = testScheduler.start { self.viewModel.showRepository.map { $0.absoluteString } }
    
    // Assert that emitted url es equal to the expected one
    XCTAssertEqual(result.events, [next(300, "https://www.apple.com")])
}