xUnit随笔

XUnit入门

1.如果之前安装了xUnit.net Visual Studio Runner扩展包，通过"工具"菜单下的"扩展和更新"先将该扩展包卸载。

2.删除临时目录中的指定文件夹：%TEMP%\VisualStudioTestExplorerExtensions

安装Xunit：

Xunit的安装现在不需要插件支持了，直接使用NuGet安装如下两个库即可：

• PM> Install-Package xunit

• PM> Install-Package xunit.runner.visualstudio -Pre (Visual Studio测试浏览器支持， VS2015目前必须装Pre的)

Comparing xUnit.net to other frameworks

Attributes

Note: This table was written back when xUnit.net 1.0 has shipped, and needs to be updated with information regarding the latest versions of the unit testing frameworks.

NUnit 2.2	MSTest 2005	xUnit.net 2.x	Comments
[Test]	[TestMethod]	[Fact]	Marks a test method.
[TestFixture]	[TestClass]	n/a	xUnit.net does not require an attribute for a test class; it looks for all test methods in all public (exported) classes in the assembly.
[ExpectedException]	[ExpectedException]	Assert.Throws Record.Exception	xUnit.net has done away with the ExpectedException attribute in favor of Assert.Throws. See Note 1
[SetUp]	[TestInitialize]	Constructor	We believe that use of [SetUp] is generally bad. However, you can implement a parameterless constructor as a direct replacement. See Note 2
[TearDown]	[TestCleanup]	IDisposable.Dispose	We believe that use of [TearDown] is generally bad. However, you can implement IDisposable.Dispose as a direct replacement. See Note 2
[TestFixtureSetUp]	[ClassInitialize]	IClassFixture<T>	To get per-class fixture setup, implement IClassFixture<T> on your test class. See Note 3
[TestFixtureTearDown]	[ClassCleanup]	IClassFixture<T>	To get per-class fixture teardown, implement IClassFixture<T> on your test class. See Note 3
n/a	n/a	ICollectionFixture<T>	To get per-collection fixture setup and teardown, implement ICollectionFixture<T> on your test collection. See Note 3
[Ignore]	[Ignore]	[Fact(Skip="reason")]	Set the Skip parameter on the [Fact] attribute to temporarily skip a test.
[Property]	[TestProperty]	[Trait]	Set arbitrary metadata on a test
n/a	[DataSource]	[Theory] [XxxData]	Theory (data-driven test). See Note 4

Attribute Notes

Note 1: Long-term use of [ExpectedException] has uncovered various problems
with it. First, it doesn’t specifically say which line of code should throw the
exception, which allows subtle and difficult-to-track failures that show up as
passing tests. Second, it doesn’t offer the opportunity to fully inspect
details of the exception itself, since the handling is outside the normal code
flow of the test. Assert.Throws allows you to test a specific set of code
for throwing an exception, and returns the exception during success so you can
write further asserts against the exception instance itself.

Note 2: The xUnit.net team feels that
per-test setup and teardown creates difficult-to-follow and debug testing code,
often causing unnecessary code to run before every single test is run. For more
information, see http://jamesnewkirk.typepad.com/posts/2007/09/why-you-should-.html.

Note 3: xUnit.net provides a new way to
think about per-fixture data with the use of the IClassFixture<T> and ICollectionFixture<T> interfaces. The runner will
create a single instance of the fixture data and pass it through to your
constructor before running each test. All the tests share the same instance of
fixture data. After all the tests have run, the runner will dispose of the
fixture data, if it implements IDisposable. For more information, see Shared Context.

Note 4: xUnit.net ships with support for
data-driven tests call Theories. Mark your test with the [Theory] attribute (instead of [Fact]), then decorate it with one or
more [XxxData] attributes, including [InlineData] and [MemberData]. For more information, see Getting Started.

Assertions

Note: this
table was written back when xUnit.net 1.0 has shipped, and needs to be updated
with information regarding the latest versions of the unit testing frameworks.

NUnit 2.2	MSTest 2005	xUnit.net 1.x	Comments
AreEqual	AreEqual	Equal	MSTest and xUnit.net support generic versions of this method
AreNotEqual	AreNotEqual	NotEqual	MSTest and xUnit.net support generic versions of this method
AreNotSame	AreNotSame	NotSame
AreSame	AreSame	Same
Contains	Contains	Contains
DoAssert	n/a	n/a
n/a	DoesNotContain	DoesNotContain
n/a	n/a	DoesNotThrow	Ensures that the code does not throw any exceptions
Fail	Fail	n/a	xUnit.net alternative: Assert.True(false, "message")
Greater	n/a	n/a	xUnit.net alternative: Assert.True(x > y)
Ignore	Inconclusive	n/a
n/a	n/a	InRange	Ensures that a value is in a given inclusive range (note: NUnit and MSTest have limited support for InRange on their AreEqual methods)
IsAssignableFrom	n/a	IsAssignableFrom
IsEmpty	n/a	Empty
IsFalse	IsFalse	False
IsInstanceOfType	IsInstanceOfType	IsType
IsNaN	n/a	n/a	xUnit.net alternative: Assert.True(double.IsNaN(x))
IsNotAssignableFrom	n/a	n/a	xUnit.net alternative: Assert.False(obj is Type)
IsNotEmpty	n/a	NotEmpty
IsNotInstanceOfType	IsNotInstanceOfType	IsNotType
IsNotNull	IsNotNull	NotNull
IsNull	IsNull	Null
IsTrue	IsTrue	True
Less	n/a	n/a	xUnit.net alternative: Assert.True(x < y)
n/a	n/a	NotInRange	Ensures that a value is not in a given inclusive range
n/a	n/a	Throws	Ensures that the code throws an exact exception

Copyright © 2015 Outercurve Foundation. Contributions
welcomed at https://github.com/xunit/xunit.github.io.

测试方式说明：

声明测试用例：

Xunit里面不需要TestClass之类Attribute来标记测试用例类，只需要满足如下条件即可：

• 测试类必须是public的
• 测试用例用
  FactAttribute 标记

断言：

Assert类用来验证测试测试函数的输出结果。

Assert.Equal(3, Math.Max(3, 2));

也可以使用一些扩展的断言库，常用的就是xunit.should库，它是以扩展函数的方式进行验证，看起来更加舒服。

PM> Install-Package xunit.should

Math.Max(3, 2).ShouldBe(3);

构建和析构：

Xunit里面并不是通过SetUp和TearDown标记来表明测试用例的构建和析构操作，它每次执行测试用例的时候都会插件测试用例类，执行完成后，如果其实现了IDispose接口，则会调用Dispose函数，更加简洁明了。也就是说：

• 在测试用例类的构造函数指向数据构建操作，
• 在Dispose函数中指向数据清理操作

异常测试

Xunit并不是通过Attribute来标记异常捕获的，而是直接使用Assert.Throws断言函数来验证异常。

public class TestClass1
    {
        [ Fact]
         public void testException()
        {
             Assert.Throws<InvalidOperationException>(()
=> operation());
        }
         void operation()
        {
             throw
new InvalidOperationException();
        }
    }

更改测试用例名称：

[ Fact(DisplayName = "Max 函数测试 " )]

跳过测试用例：

[ Fact(Skip = " 重构未完成 " )]

分组：

[ Trait("Group", "Category")]