单元测试RxCocoa驱动程序时未调用onNext

let observable = ... // 你的Observable
observable
    .observeOn(MainScheduler.instance)
    .subscribe(onNext: { value in
        print("Received value: \(value)")
    })
    .disposed(by: disposeBag)

observable
    .observeOn(MainScheduler.instance)
    .subscribe(onNext: { value in
        print("Received value: \(value)")
    })
    .disposed(by: disposeBag)

let mockObservable = Observable.just("Test Value")
mockObservable
    .observeOn(MainScheduler.instance)
    .subscribe(onNext: { value in
        print("Received value: \(value)")
    })
    .disposed(by: disposeBag)

func testObservable() {
    let expectation = XCTestExpectation(description: "Observable should emit a value")

    let observable = Observable.just("Test Value")
    observable
        .observeOn(MainScheduler.instance)
        .subscribe(onNext: { value in
            XCTAssertEqual(value, "Test Value")
            expectation.fulfill()
        })
        .disposed(by: disposeBag)

    wait(for: [expectation], timeout: 1.0)
}

observable
    .do(onNext: { value in
        print("Emitting value: \(value)")
    })
    .observeOn(MainScheduler.instance)
    .subscribe(onNext: { value in
        print("Received value: \(value)")
    })
    .disposed(by: disposeBag)

observable
    .observeOn(MainScheduler.instance)
    .subscribe(onNext: { value in
        print("Received value: \(value)")
    }, onError: { error in
        XCTFail("Error occurred: \(error)")
    })
    .disposed(by: disposeBag)

import XCTest
import RxCocoa
import RxSwift

class MyViewModel {
    let data = BehaviorRelay<String?>(value: nil)

    func fetchData() {
        // Simulate fetching data
        self.data.accept("New Data")
    }
}

class MyViewModelTests: XCTestCase {
    let disposeBag = DisposeBag()

    func testFetchData() {
        let viewModel = MyViewModel()
        let expectation = XCTestExpectation(description: "Data should be updated")

        viewModel.data
            .observeOn(MainScheduler.instance)
            .subscribe(onNext: { data in
                XCTAssertEqual(data, "New Data")
                expectation.fulfill()
            })
            .disposed(by: disposeBag)

        viewModel.fetchData()
        wait(for: [expectation], timeout: 1.0)
    }
}