Can't fix: Error CS1029 'Generation error: Sequence contains no elements'
Can't fix: Error CS1029 'Generation error: Sequence contains no elements'
我正在尝试进行第一次自动测试，但我一直收到此错误：
Error CS1029 #error: 'Generation error: Sequence contains no elements'.
我的 specflow 功能：
Feature: SpecFlowFeature1
In order to see and check my todos
As planning user
I want to create and see my todos and done todos
@mytag
Scenario: Check default number of todos
Given user is on todolist.me main page
Then user sees list of 7 todo''s
Scenario Outline: Check todos creation
Given user is on todolist.me main page
When user creates new todo with content: <content>
Then user sees todo with content: <content>
Scenario Outline: Chech todos can be checked and mark as done
Given user is on todolist.me main page
When user creates new todo with text: <text>
Then user checks the todo with text: <text>
Then user sees no todo with text: <text>
Then user sees done todo with text: <text>
Examples:
| content |
| just plain text |
| 1234567890 |
| ~!@#$%^&*()_-+<>|
Examples:
| text |
| customToDoText |
我的配置：
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using TechTalk.SpecFlow;
using OpenQA.Selenium;
using OpenQA.Selenium.Chrome;
namespace UnitTestProject1
{
[Binding]
public class Conf
{
private static IWebDriver driver = new ChromeDriver();
public static IWebDriver GetDriver()
{
driver.Manage().Timeouts().ImplicitWait = TimeSpan.FromSeconds(5);
driver.Manage().Window.Maximize();
return driver;
}
[AfterTestRun]
public static void AfterTestRun()
{
driver.Quit();
}
}
}
我的步数：
using System;
using TechTalk.SpecFlow;
using OpenQA.Selenium;
using OpenQA.Selenium.Chrome;
using NUnit.Framework;
using OpenQA.Selenium.Interactions;
using System.Collections.Generic;
using System.Linq;
namespace UnitTestProject1
{
[Binding]
public class SpecFlowFeature1Steps
{
private static IWebDriver driver = Conf.GetDriver();
[Given(@"user is on todolist.me main page")]
public void NavigateToTodoList()
{
driver.Navigate().GoToUrl("http://todolistme.net");
}
[When(@"user creates new todo with content: (.*)")]
public void WhenUserCreatesNewTodoWithContent(String todoContent)
{
driver.FindElement(By.Id("newtodo")).SendKeys(todoContent);
new Actions(driver).SendKeys(Keys.Enter).Build().Perform();
}
[When(@"user creates new todo with text: (.*)")]
public void WhenUserCreatesNewTodoWithText(String todoText)
{
driver.FindElement(By.Id("newtodo")).SendKeys(todoText);
new Actions(driver).SendKeys(Keys.Enter).Build().Perform();
}
[Then(@"user sees list of (.*) todo's")]
public void ThenUserSeesListOfTodoS(int count)
{
Assert.AreEqual(count, driver.FindElements(By.XPath("//span[contains(@id, 'mytodo')]")).Count);
}
[Then(@"user sees todo with content: (.*)")]
public void ThenUserSeesTodoWithContent(String todoContent)
{
List<IWebElement> list = driver.FindElements(By.XPath("//span[contains(@id, 'mytodo')]")).ToList();
IWebElement elem = list.Find(x => x.Text.Equals(todoContent));
Assert.AreEqual(todoContent, elem.Text);
}
[Then(@"user checks the todo with text: (.*)")]
public void ThenUserChecksTheTodoWithText(String todoText)
{
var listItem = driver.FindElement(By.XPath("//li[./span[contains(text(), 'customToDo')]]/input"));
new Actions(driver).Click(listItem);
}
[Then(@"user sees no todo with text: (.*)")]
public void ThenUserSeesNoTodoWithText(String todoText)
{
List<IWebElement> list = driver.FindElements(By.XPath("//ul[contains(@id, 'mytodos')]//span[contains(@id, 'mytodo')]")).ToList();
IWebElement elem = list.Find(x => x.Text.Equals(todoText));
Assert.AreNotEqual(todoText, elem.Text);
}
[Then(@"user sees done todo with text: (.*)")]
public void ThenUserSeesDoneTodoWithText(String todoText)
{
List<IWebElement> list = driver.FindElements(By.XPath("//ul[contains(@id, 'mydonetodos')]//span[contains(@id, 'mytodo')]")).ToList();
IWebElement elem = list.Find(x => x.Text.Equals(todoText));
Assert.AreEqual(todoText, elem.Text);
}
}
}
所有这些之后我得到一个错误：
Error CS1029 #error: 'Generation error: Sequence contains no elements'
我该怎么做才能解决这个问题？
我认为这是因为您的列表 return 没有任何 items/elements 在这里
WebElement elem = list.Find(x => x.Text.Equals(todoText));
但是在你的代码中Assert.AreEqual(todoText, elem.Text);
您访问了一个空对象，这导致了这个错误。
您需要检查 elem 是否不为空：
if(elem != null)
{
Assert.AreEqual(todoText, elem.Text);
}
在没有返回任何元素的 LINQ 查询上调用扩展方法时会引发此错误。
所以如果不存在id为mytodos的ul元素，在下面的代码中调用.ToList()就会报错
List<IWebElement> list = driver.FindElements(By.XPath("//ul[contains(@id, 'mytodos')]//span[contains(@id, 'mytodo')]")).ToList()
此外，不会导致错误，但 id 属性应该是唯一的。而不是使用
<ul id='mytodo'></ul>
您应该使用 class 属性：
<ul class='mytodo'></ul>
您应该首先调用查找元素并检查它是否不为空且包含元素。
List<IWebElement> list = null;
var elements = driver.FindElements(By.XPath("//ul[contains(@class, 'mytodos')]//span[contains(@id, 'mytodo')]"));
if (elements!=null && elmenents.Count>0){
list = elements.ToList();
}
我知道答案已被接受，但我找到了不同的解决方案。
我认为问题在于您按顺序指定了两个场景大纲，然后将示例放在它们下面。当您使用场景大纲时，系统需要在您指定另一个场景之前有一个示例块。因此，如果您只是将第一个示例块移动到两个场景大纲之间，错误就不会再发生了。您的功能文件应如下所示：
Feature: SpecFlowFeature1
In order to see and check my todos
As planning user
I want to create and see my todos and done todos
@mytag
Scenario: Check default number of todos
Given user is on todolist.me main page
Then user sees list of 7 todo''s
Scenario Outline: Check todos creation
Given user is on todolist.me main page
When user creates new todo with content: <content>
Then user sees todo with content: <content>
Examples:
| content |
| just plain text |
| 1234567890 |
| ~!@#$%^&*()_-+<>|
Scenario Outline: Chech todos can be checked and mark as done
Given user is on todolist.me main page
When user creates new todo with text: <text>
Then user checks the todo with text: <text>
Then user sees no todo with text: <text>
Then user sees done todo with text: <text>
Examples:
| text |
| customToDoText |
我在使用 SpecFlow 时遇到了同样的问题，但我的情况略有不同：
因为我想对两个“场景大纲”使用相同的“示例”部分，所以我想我可以把它放在两个的最后。但这没有用。
问题真的出在元素的正确顺序上
（另请参阅：“示例”下的 Step Arguments in Cucumber）：
在“场景大纲”之后必须跟随“示例”部分，无论您是否对多个“场景大纲”使用相同的“示例”部分！否则你会得到描述的错误。
您不能将所有“示例”部分或多个“场景大纲”的一个“示例”部分放在功能文件的末尾。 ;-)
我希望，这可以帮助 运行 遇到同样问题的其他人。
当您有 Scenario Outline 但没有 Example 部分时，您也可能会遇到此错误。
在这种情况下，您需要将其从 Scenario Outline 更改为 Scenario。
我正在尝试进行第一次自动测试，但我一直收到此错误：
Error CS1029 #error: 'Generation error: Sequence contains no elements'.
我的 specflow 功能：
Feature: SpecFlowFeature1
In order to see and check my todos
As planning user
I want to create and see my todos and done todos
@mytag
Scenario: Check default number of todos
Given user is on todolist.me main page
Then user sees list of 7 todo''s
Scenario Outline: Check todos creation
Given user is on todolist.me main page
When user creates new todo with content: <content>
Then user sees todo with content: <content>
Scenario Outline: Chech todos can be checked and mark as done
Given user is on todolist.me main page
When user creates new todo with text: <text>
Then user checks the todo with text: <text>
Then user sees no todo with text: <text>
Then user sees done todo with text: <text>
Examples:
| content |
| just plain text |
| 1234567890 |
| ~!@#$%^&*()_-+<>|
Examples:
| text |
| customToDoText |
我的配置：
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using TechTalk.SpecFlow;
using OpenQA.Selenium;
using OpenQA.Selenium.Chrome;
namespace UnitTestProject1
{
[Binding]
public class Conf
{
private static IWebDriver driver = new ChromeDriver();
public static IWebDriver GetDriver()
{
driver.Manage().Timeouts().ImplicitWait = TimeSpan.FromSeconds(5);
driver.Manage().Window.Maximize();
return driver;
}
[AfterTestRun]
public static void AfterTestRun()
{
driver.Quit();
}
}
}
我的步数：
using System;
using TechTalk.SpecFlow;
using OpenQA.Selenium;
using OpenQA.Selenium.Chrome;
using NUnit.Framework;
using OpenQA.Selenium.Interactions;
using System.Collections.Generic;
using System.Linq;
namespace UnitTestProject1
{
[Binding]
public class SpecFlowFeature1Steps
{
private static IWebDriver driver = Conf.GetDriver();
[Given(@"user is on todolist.me main page")]
public void NavigateToTodoList()
{
driver.Navigate().GoToUrl("http://todolistme.net");
}
[When(@"user creates new todo with content: (.*)")]
public void WhenUserCreatesNewTodoWithContent(String todoContent)
{
driver.FindElement(By.Id("newtodo")).SendKeys(todoContent);
new Actions(driver).SendKeys(Keys.Enter).Build().Perform();
}
[When(@"user creates new todo with text: (.*)")]
public void WhenUserCreatesNewTodoWithText(String todoText)
{
driver.FindElement(By.Id("newtodo")).SendKeys(todoText);
new Actions(driver).SendKeys(Keys.Enter).Build().Perform();
}
[Then(@"user sees list of (.*) todo's")]
public void ThenUserSeesListOfTodoS(int count)
{
Assert.AreEqual(count, driver.FindElements(By.XPath("//span[contains(@id, 'mytodo')]")).Count);
}
[Then(@"user sees todo with content: (.*)")]
public void ThenUserSeesTodoWithContent(String todoContent)
{
List<IWebElement> list = driver.FindElements(By.XPath("//span[contains(@id, 'mytodo')]")).ToList();
IWebElement elem = list.Find(x => x.Text.Equals(todoContent));
Assert.AreEqual(todoContent, elem.Text);
}
[Then(@"user checks the todo with text: (.*)")]
public void ThenUserChecksTheTodoWithText(String todoText)
{
var listItem = driver.FindElement(By.XPath("//li[./span[contains(text(), 'customToDo')]]/input"));
new Actions(driver).Click(listItem);
}
[Then(@"user sees no todo with text: (.*)")]
public void ThenUserSeesNoTodoWithText(String todoText)
{
List<IWebElement> list = driver.FindElements(By.XPath("//ul[contains(@id, 'mytodos')]//span[contains(@id, 'mytodo')]")).ToList();
IWebElement elem = list.Find(x => x.Text.Equals(todoText));
Assert.AreNotEqual(todoText, elem.Text);
}
[Then(@"user sees done todo with text: (.*)")]
public void ThenUserSeesDoneTodoWithText(String todoText)
{
List<IWebElement> list = driver.FindElements(By.XPath("//ul[contains(@id, 'mydonetodos')]//span[contains(@id, 'mytodo')]")).ToList();
IWebElement elem = list.Find(x => x.Text.Equals(todoText));
Assert.AreEqual(todoText, elem.Text);
}
}
}
所有这些之后我得到一个错误：
Error CS1029 #error: 'Generation error: Sequence contains no elements'
我该怎么做才能解决这个问题？
我认为这是因为您的列表 return 没有任何 items/elements 在这里
WebElement elem = list.Find(x => x.Text.Equals(todoText));
但是在你的代码中Assert.AreEqual(todoText, elem.Text);
您访问了一个空对象，这导致了这个错误。
您需要检查 elem 是否不为空：
if(elem != null)
{
Assert.AreEqual(todoText, elem.Text);
}
在没有返回任何元素的 LINQ 查询上调用扩展方法时会引发此错误。
所以如果不存在id为mytodos的ul元素，在下面的代码中调用.ToList()就会报错
List<IWebElement> list = driver.FindElements(By.XPath("//ul[contains(@id, 'mytodos')]//span[contains(@id, 'mytodo')]")).ToList()
此外，不会导致错误，但 id 属性应该是唯一的。而不是使用
<ul id='mytodo'></ul>
您应该使用 class 属性：
<ul class='mytodo'></ul>
您应该首先调用查找元素并检查它是否不为空且包含元素。
List<IWebElement> list = null;
var elements = driver.FindElements(By.XPath("//ul[contains(@class, 'mytodos')]//span[contains(@id, 'mytodo')]"));
if (elements!=null && elmenents.Count>0){
list = elements.ToList();
}
我知道答案已被接受，但我找到了不同的解决方案。
我认为问题在于您按顺序指定了两个场景大纲，然后将示例放在它们下面。当您使用场景大纲时，系统需要在您指定另一个场景之前有一个示例块。因此，如果您只是将第一个示例块移动到两个场景大纲之间，错误就不会再发生了。您的功能文件应如下所示：
Feature: SpecFlowFeature1
In order to see and check my todos
As planning user
I want to create and see my todos and done todos
@mytag
Scenario: Check default number of todos
Given user is on todolist.me main page
Then user sees list of 7 todo''s
Scenario Outline: Check todos creation
Given user is on todolist.me main page
When user creates new todo with content: <content>
Then user sees todo with content: <content>
Examples:
| content |
| just plain text |
| 1234567890 |
| ~!@#$%^&*()_-+<>|
Scenario Outline: Chech todos can be checked and mark as done
Given user is on todolist.me main page
When user creates new todo with text: <text>
Then user checks the todo with text: <text>
Then user sees no todo with text: <text>
Then user sees done todo with text: <text>
Examples:
| text |
| customToDoText |
我在使用 SpecFlow 时遇到了同样的问题，但我的情况略有不同： 因为我想对两个“场景大纲”使用相同的“示例”部分，所以我想我可以把它放在两个的最后。但这没有用。
问题真的出在元素的正确顺序上 （另请参阅：“示例”下的 Step Arguments in Cucumber）： 在“场景大纲”之后必须跟随“示例”部分，无论您是否对多个“场景大纲”使用相同的“示例”部分！否则你会得到描述的错误。
您不能将所有“示例”部分或多个“场景大纲”的一个“示例”部分放在功能文件的末尾。 ;-)
我希望，这可以帮助 运行 遇到同样问题的其他人。
当您有 Scenario Outline 但没有 Example 部分时，您也可能会遇到此错误。
在这种情况下，您需要将其从 Scenario Outline 更改为 Scenario。