Specflow

Question

我正在使用 Specflow 和 Selenium 进行测试自动化，但是当我尝试执行测试时，我遇到了这些错误消息：

我的问题不是什么是 NullReferenceException，而是这个 参数 'key' 是什么（以及在哪里）被指出为异常的原因。

TearDown failed for test fixture MyProject.Features.MyFeature System.ArgumentNullException : Value cannot be null. (Parameter 'key') TearDown : System.NullReferenceException : Object reference not set to an instance of an object.

并且：

Error Message: OneTimeSetUp: System.ArgumentNullException : Value cannot be null. (Parameter 'key')

这是我的场景：

Scenario: Accessing the screen for the first time
    Given I accessed the screen for the first time
    Then the result grid should only show the phrase "Lorem ipsum"

这是我的 StepDefinition.cs 文件：

    [Binding]
    public class StepDefinition
    {
        PageObject pageObject = new PageObject();

        [Given(@"I accessed the screen for the first time")]
        public void GivenIAccessedTheScreenForTheFirstTime()
        {
            pageObject.NavigateToScreen();
        }

        [Then(@"the result grid should only show the phrase (.*)")]
        public void ThenTheResultGridShouldOnlyShowThePhrase(string phrase)
        {
            Assert.True(pageObject.isPhraseDisplayed(phrase));
        }        
    }

这是我的 PageObject.cs 文件：

        public PageObject() : base(){ } //I use a BasePageObject.cs file also

        public void NavigateToScreen()
        {
            driver.Navigate().GoToUrl(_urlHere_);
        }
        public bool isPhraseDisplayed(string phrase)
        {
            wait.Until(u => u.FindElement(_byIdOfWebElementHere_).Displayed);

            IWebElement element = driver.FindElement(_byIdOfWebElementHere_);
            return element.Displayed;
        }

这是实现 IDisposable 接口的 BasePageObject.cs 文件：

        protected IWebDriver driver { get; set; }
        protected WebDriverWait wait { get; set; }

        public BasePageObject()
        {
            driver = new ChromeDriver();
        }

        [AfterScenario]
        public void Dispose()
        {
            driver.Close();
            driver.Quit();
            driver.Dispose();
        }
    }

异常堆栈跟踪：

Starting test execution, please wait...

A total of 1 test files matched the specified pattern.
TearDown failed for test fixture MyProject.Features.MyFeature
System.ArgumentNullException : Value cannot be null. (Parameter 'key')
TearDown : System.NullReferenceException : Object reference not set to an instance of an object.
   at System.Collections.Generic.Dictionary`2.FindEntry(TKey key)
   at System.Collections.Generic.Dictionary`2.TryGetValue(TKey key, TValue& value)
   at TechTalk.SpecFlow.Bindings.Discovery.RuntimeBindingRegistryBuilder.FindAttributeConstructorArg(ParameterInfo parameterInfo, Dictionary`2 namedAttributeValues)
   at TechTalk.SpecFlow.Bindings.Discovery.RuntimeBindingRegistryBuilder.<>c__DisplayClass8_0.<CreateAttribute>b__7(ParameterInfo p)
   at System.Linq.Enumerable.SelectArrayIterator`2.ToArray()
   at System.Linq.Enumerable.ToArray[TSource](IEnumerable`1 source)
   at TechTalk.SpecFlow.Bindings.Discovery.RuntimeBindingRegistryBuilder.CreateAttribute(Attribute attribute)
   at System.Linq.Enumerable.WhereSelectEnumerableIterator`2.ToArray()
   at System.Linq.Enumerable.ToArray[TSource](IEnumerable`1 source)
   at TechTalk.SpecFlow.Bindings.Discovery.RuntimeBindingRegistryBuilder.GetAttributes(IEnumerable`1 customAttributes)
   at TechTalk.SpecFlow.Bindings.Discovery.RuntimeBindingRegistryBuilder.CreateBindingSourceMethod(MethodInfo methodDefinition)
   at TechTalk.SpecFlow.Bindings.Discovery.RuntimeBindingRegistryBuilder.BuildBindingsFromType(Type type)
   at TechTalk.SpecFlow.Bindings.Discovery.RuntimeBindingRegistryBuilder.BuildBindingsFromAssembly(Assembly assembly)
   at TechTalk.SpecFlow.TestRunnerManager.BuildBindingRegistry(IEnumerable`1 bindingAssemblies)
   at TechTalk.SpecFlow.TestRunnerManager.InitializeBindingRegistry(ITestRunner testRunner)
   at TechTalk.SpecFlow.TestRunnerManager.CreateTestRunner(Int32 threadId)
   at TechTalk.SpecFlow.TestRunnerManager.GetTestRunnerWithoutExceptionHandling(Int32 threadId)
   at TechTalk.SpecFlow.TestRunnerManager.GetTestRunner(Int32 threadId)
   at TechTalk.SpecFlow.TestRunnerManager.GetTestRunner(Assembly testAssembly, Nullable`1 managedThreadId)
   at MyProject.Features.MyFeature.FeatureSetup()
--TearDown
   at MyProject.Features.MyFeature.FeatureTearDown()
  X AcessandoATelaDeConsultaPelaPrimeiraVez [< 1ms]
  Error Message:
   OneTimeSetUp: System.ArgumentNullException : Value cannot be null. (Parameter 'key')

Results File: C:\Users\FAMG\AppData\Local\Temp\test-explorer-GvcYR7[=16=].trx

Total tests: 1
     Failed: 1
 Total time: 3,7733 Seconds

我认为重要的点：

我正在使用 VSCode，而不是 Visual Studio。
我在项目中安装的测试运行器是 NUnit。

Answer 1

我只是运行这件事。
错误的根源来自对类型的反思：System.Runtime.CompilerServices.NullableContextAttribute.

看起来像是某种预期的构造函数 MethodInfo Name is NULL。

长话短说：.NET Core 2.1、2.2 可用。 SpecFlow (3.0.225) 似乎不适用于 .Net Core 3.0。

好消息：打开包含 Nuget 的预发布版并获取 Beta SpecFlow 和相关包（Nunit 和朋友）更新到 (3.1.52-beta) 最新作品。

SpecFlow 3.1 主版本可能会支持 .Net Core 3.0。

Specflow - 测试夹具的拆卸失败 - System.ArgumentNullException：值不能为空。（参数'key'）

Specflow - TearDown failed for test fixture - System.ArgumentNullException : Value cannot be null. (Parameter 'key')

c#

nunit

automated-tests

visual-studio-code

Specflow - 测试夹具的拆卸失败 - System.ArgumentNullException：值不能为空。 （参数'key'）

Specflow - TearDown failed for test fixture - System.ArgumentNullException : Value cannot be null. (Parameter 'key')

c#

nunit

automated-tests

specflow

visual-studio-code

Specflow - 测试夹具的拆卸失败 - System.ArgumentNullException：值不能为空。（参数'key'）