编写简单的api调用测试

Question

我想为与 API 交互的函数编写一个测试。我最终得到：

class FileDownloaderTests: XCTestCase {

    // MARK: timeouts

    let regularTimeout: TimeInterval = 10
    let largeTimeout: TimeInterval = 15

    func testDownload() {
        // URLS.firstFileUrl.rawValue
        let downloader = FileDownloader(string: URLS.firstFileUrl.rawValue)
        downloader.download(successCompletion: {
            XCTAssertTrue(true)
        }) { error in
            print("error in test - \(error)")
        }

        waitForExpectations(timeout: largeTimeout, handler: nil)
    }
}

因此，它假设等待 largeTimeout（15 秒）来 successCompletion 关闭，然后测试应该通过。但最终还是报错了：

*** Assertion failure in -[FileDownloaderTests.FileDownloaderTests waitForExpectationsWithTimeout:handler:], /Library/Caches/com.apple.xbs/Sources/XCTest_Sim/XCTest-14460.20/Sources/XCTestFramework/Async/XCTestCase+AsynchronousTesting.m:28
/Users/Necrosoft/Documents/Programming/Work/Life-Pay/FileDownloader/FileDownloaderTests/FileDownloaderTests.swift:28: error: -[FileDownloaderTests.FileDownloaderTests testDownload] : failed: caught "NSInternalInconsistencyException", "API violation - call made to wait without any expectations having been set."

Answer 1

你需要fulfill告诉期望它可以停止等待/进程已经完成

func testDownload() {
    // URLS.firstFileUrl.rawValue
    let downloader = FileDownloader(string: URLS.firstFileUrl.rawValue)
    downloader.download(successCompletion: {
        XCTAssertTrue(true)
        expectation.fulfill()
    }) { error in
        print("error in test - \(error)")
        expectation.fulfill()
    }

    waitForExpectations(timeout: largeTimeout, handler: nil)
}

注意：针对实时 API 运行自动化测试通常不是一个好主意。您应该使用存根响应来测试您对代码的处理是否正确，或者至少针对测试/登台 API 进行测试。

编辑：你有两个完成处理程序，所以我在每个处理程序中调用了fulfill