blocks|key|1079852|text|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1079853|我的印象是，单元测试是一些代码，它使用设置的值调用应用程序的方法，并期望返回特定值，如果特定值没有返回，则测试失败。这里是我错了还是误导了？|blockquote|1079854|1079855|1079856|不，你是完全正确的。|1079857|单元测试的重要之处在于尽可能测试一小段代码。|1079858|在您的示例中，您从数据库中获取一些内容，然后计算项目的数量……如果你的方法失败了，你永远不会确切地知道哪里出了问题，因为有太多的事情可能会出错……|1079859|您的数据库连接可能会丢失，sql无效，...|1079860|如果您使用的是asp.net+MVC，那么编写单元测试应该比使用普通的asp.net更容易。|1079861|entityMap^0|0|0|0|0|0|0|0|0|0^^$0|@$1|2|3|-4|4|5|6|R|7|@]|8|@]|9|$]]|$1|A|3|B|4|C|6|S|7|@]|8|@]|9|$]]|$1|D|3|-4|4|5|6|T|7|@]|8|@]|9|$]]|$1|E|3|-4|4|5|6|U|7|@]|8|@]|9|$]]|$1|F|3|G|4|5|6|V|7|@]|8|@]|9|$]]|$1|H|3|I|4|5|6|W|7|@]|8|@]|9|$]]|$1|J|3|K|4|5|6|X|7|@]|8|@]|9|$]]|$1|L|3|M|4|5|6|Y|7|@]|8|@]|9|$]]|$1|N|3|O|4|5|6|Z|7|@]|8|@]|9|$]]|$1|P|3|-4|4|5|6|10|7|@]|8|@]|9|$]]]|Q|$]]

<blockquote>
 I am under the impression that a unit test is some code that makes a call to a method of your app with a set value and expects a specific value to come back, if the specific value does not come back the test has failed. Am I wrong or mislead here?
</blockquote>

Nope, you are exactly right.

The important thing with unit tests is to test a small a piece of code as possible.

In your example you get something from the db and then count the number of items... If your method fails, you'll never know exactly where the things went wrong because there is so much that could go wrong....

Your db-connection could be lost, sql invalid, ...

If you are using asp.net MVC, you should have an easier time writing unit tests than if you were using normal asp.net

blocks|key|4864847|text|单元测试是一种测试您的代码的一小部分，通常是单个方法(准确地说是一个单元)。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4864848|在TDD中，开发人员能够在编写方法之前编写单元测试，因为他们已经知道代码单元应该做什么。如何进行work...the测试并不重要，只需确保结果正确即可。|4864849|该伪代码可以用作单元测试(不确定它将测试什么，但我必须假设您测试的方法不应该返回重复的SubDomains)。|4864850|理论上，单元测试(和测试驱动开发)应该通过确保代码的每个单元都能准确地完成预期的工作来减轻未来的麻烦。|4864851|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|J|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|K|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|L|8|@]|9|@]|A|$]]|$1|F|3|G|5|6|7|M|8|@]|9|@]|A|$]]|$1|H|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|I|$]]

A Unit Test is a test that exercises a very small portion of your code, usually a single method (a Unit to be exact).

In TDD, developers are able to write the Unit Test before coding the method because they already know what the Unit of code should do. It doesn't matter how it does the work...the test just makes sure the results are correct.

And that pseudo-code could be used as a Unit test (not sure what it would be testing, but I would have to assume you're testing a method that shouldn't return duplicate SubDomains).

The theory is Unit Testing (and Test Driven Development) should alleviate headaches further down the road by making sure each Unit of code does exactly what is expected of it.

blocks|key|1136041|text|您关于单元测试的看法是正确的。这个想法是用不同的输入一个接一个地测试你的所有函数，以确保它们像你期望的那样工作(而不是在它们被插入到应用程序中之后发现它们。然后使测试更加复杂)。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1136042|在编写函数之前编写单元测试是称为“测试驱动开发”的方法的一部分。你只需要编写函数的框架，而所有的单元测试都是先来的。所以一开始你的所有测试都会失败(b/c函数还没有被编程)。之后，您可以编写函数，直到所有测试通过为止。|1136043|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|F|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|G|8|@]|9|@]|A|$]]|$1|D|3|-4|5|6|7|H|8|@]|9|@]|A|$]]]|E|$]]

You are correct about unit testing. The idea is to test all your functions, one by one, with different inputs to make sure they work like you expect (as opposed to finding out after they've been inserted into an application.. and then making the testing more complicated).

Writing the unit tests before you write the function is part of a methodology called "Test driven development". In which you write the skeleton of the function only, and all the unit tests first. So at first all your tests will fail (b/c the function is not programmed yet). After that you program the function until all the tests pass.

blocks|key|1142003|text|是的，您的示例将是单元测试。首先创建测试有几个原因。首先，它作为你的项目的活文档。它建立了行为和预期结果，这应该有助于你实际实现你的代码(更容易写一些东西，知道它需要做什么，以及它基本上是如何启动的)。其次，如果您在之后编写测试，则更有可能编写与您已经编写的代码一起工作的测试，这对您没有帮助。定义代码单元需要做什么，编写测试，并编写/修复代码，以便它反映测试中的行为。随着应用程序的发展，此策略将转化为更好的理解和质量。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1142004|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

Yes, your example would be a unit test. There are a few reasons to create the test first. First, it acts as living documentation for your project. It establishes behaviors and expected outcomes, which should help you actually implement your code (it's easier to write something, knowing what it needs to do and basically how it is initiated). Secondly, if you write the test afterward, you're more likely to write a test that works with the code you already wrote, which doesn't help you. Define what a unit of code needs to do, write the tests, and write/fix the code so it reflects the behaviors in the tests. This strategy translates into improved understanding and quality as your application evolves.

blocks|key|1136099|text|单元测试是单元级别的自动化测试。单元级指的是原子代码单元，这样你就不能进一步分解它。函数或对象的特定部分。一个正方形函数的单元测试如下所示|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1136100|+assertEqual(4,+square(2));
+assertEqual(4,+square(-2));
+assertEqual(0,+square(0));|code-block|syntax|javascript|1136101|现在，一旦你决定了square的接口，你就可以写这段代码，对于一个更复杂的函数，你可以通过多少次测试来衡量完成函数的距离。|1136102|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

Unit testing is automated testing at the Unit level. By unit level they mean atomic code unit such that you can't break it down further. a function or a particular part of an object. a unit test for a square function would look something like 

<pre><code> assertEqual(4, square(2));
 assertEqual(4, square(-2));
 assertEqual(0, square(0));
</code></pre>

Now you can write this as soon as you have decided on the interface of square, for a more complicated function you could measure how close to complete the function is by how many tests pass.

blocks|key|3396427|text|在最初从jUnit派生的xUnit框架家族中，有非常完善的单元测试约定。在该框架中，断言是进行测试的主要工具。在测试套件中，目标是确保100%25的断言是正确的。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3396428|考虑一下你的例子。|3396429|CheckForDuplicateSubdomains(){
++get+all+users+in+DB+with+matching+subdomains
++if+greater+than+zero,+fail+test
}|code-block|syntax|javascript|3396430|这个测试通常会有一个以"+test“开头的名称，这让框架的测试运行者知道这个函数是一个测试，而不是一个设置方法。我们测试的是代码的行为，而不是数据的状态，这一点很重要。|3396431|testNoDuplicateSubdomains(){
}|3396432|在每个测试中，都有four+phases：|offset|length|3396433|3396434|fixture+setup、|unordered-list-item|3396435|exercise+SUT、|3396436|result+exercise和|3396437|fixture+teardown。|3396438|3396439|SUT是“被测系统”，它通常是产品代码中类的一种方法。|3396440|testNoDuplicateSubdomains(){
++//+fixture+setup
++prepareDatabaseTestData()
++//+exercise+SUT,+
++SUT+=+new+ProductionObject()
++result+=+SUT.getAllUsersWithMatchingSubDomains()
++//+result+verification+and+
++assertEmpty(result)+//+or+whatever+makes+sense
++//+fixture+teardown.++
++removeDatabaseTestData()
}|3396441|与许多软件开发技术一样，编写单元测试需要一段时间。Gerard+Meszaros的xUnit+Test+Patterns是学习最佳实践的好资源。|3396442|entityMap|0|LINK|mutability|MUTABLE|url|http://xunitpatterns.com/Four%2520Phase%2520Test.html|1|http://xunitpatterns.com/^0|0|0|0|0|0|9|B|0|0|0|0|0|0|0|0|0|0|15|J|1|0^^$0|@$1|2|3|4|5|6|7|1H|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|1I|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|1J|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|1K|8|@]|9|@]|A|$]]|$1|K|3|L|5|F|7|1L|8|@]|9|@]|A|$G|H]]|$1|M|3|N|5|6|7|1M|8|@]|9|@$O|1N|P|1O|1|1P]]|A|$]]|$1|Q|3|-4|5|6|7|1Q|8|@]|9|@]|A|$]]|$1|R|3|S|5|T|7|1R|8|@]|9|@]|A|$]]|$1|U|3|V|5|T|7|1S|8|@]|9|@]|A|$]]|$1|W|3|X|5|T|7|1T|8|@]|9|@]|A|$]]|$1|Y|3|Z|5|T|7|1U|8|@]|9|@]|A|$]]|$1|10|3|-4|5|6|7|1V|8|@]|9|@]|A|$]]|$1|11|3|12|5|6|7|1W|8|@]|9|@]|A|$]]|$1|13|3|14|5|F|7|1X|8|@]|9|@]|A|$G|H]]|$1|15|3|16|5|6|7|1Y|8|@]|9|@$O|1Z|P|20|1|21]]|A|$]]|$1|17|3|-4|5|6|7|22|8|@]|9|@]|A|$]]]|18|$19|$5|1A|1B|1C|A|$1D|1E]]|1F|$5|1A|1B|1C|A|$1D|1G]]]]

There are very well established conventions for unit testing in the xUnit family of frameworks, originally derived from jUnit. In that framework, the assertion is the main vehicle for making a test. In a test suite, the objective is to ensure that 100% of your assertions are true.

Consider your example.

<pre><code>CheckForDuplicateSubdomains(){
 get all users in DB with matching subdomains
 if greater than zero, fail test
}
</code></pre>

This test would conventionally have a name starting with "test", which lets the framework's test runner know that this function is a test and not a setup method, say. It is important to be clear that we are testing the behavior of the code, and not the state of the data. 

<pre><code>testNoDuplicateSubdomains(){
}
</code></pre>

Within each test, there are <a href="http://xunitpatterns.com/Four%20Phase%20Test.html" rel="nofollow noreferrer">four phases</a>: 

<ul>
<li>fixture setup, </li>
<li>exercise SUT, </li>
<li>result verification and </li>
<li>fixture teardown. </li>
</ul>

The SUT is the "system under test", which is typically one method of a class in your production code. 

<pre><code>testNoDuplicateSubdomains(){
 // fixture setup
 prepareDatabaseTestData()
 // exercise SUT, 
 SUT = new ProductionObject()
 result = SUT.getAllUsersWithMatchingSubDomains()
 // result verification and 
 assertEmpty(result) // or whatever makes sense
 // fixture teardown. 
 removeDatabaseTestData()
}
</code></pre>

As with many software development techniques, it takes a while to get experienced at writing unit tests. A good resource for learning the best practices is <a href="http://xunitpatterns.com/" rel="nofollow noreferrer">xUnit Test Patterns</a> by Gerard Meszaros.

What exactly is a unit test and how do I write one? I hear many times people write them before their app is even written, how can this be? I am under the impression that a unit test is some code that makes a call to a method of your app with a set value and expects a specific value to come back, if the specific value does not come back the test has failed. Am I wrong or mislead here? I read so much about unit testing but I know very little about what it actually looks like in code so a sample would be great.

Is this a unit test?

start psuedo code...

<pre><code>CheckForDuplicateSubdomains(){
 get all users in DB with matching subdomains
 if greater than zero, fail test
}
</code></pre>

PS: I am using ASP.NET MVC in C#

An example of unit testing in C#?

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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什么是单元测试?我该如何编写单元测试？我听说很多人甚至在他们的应用程序写之前就写了它们，这是怎么回事？我的印象是，单元测试是一些代码，它使用设置的值调用应用程序的方法，并期望返回特定值，如果特定值没有返回，则测试失败。这里是我错了还是误导了？我读了很多关于单元测试的书，但我对它在代码中的实际外观知之甚少，所以一个示例就...

问在C#中进行单元测试的示例？
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