C# – How to we run a test method with multiple parameters in MSTest

cmstestnunitunit testingvs-unit-testing-framework

NUnit has a feature called Values, like below:

[Test]
public void MyTest(
    [Values(1,2,3)] int x,
    [Values("A","B")] string s)
{
    // ...
}

This means that the test method will run six times:

MyTest(1, "A")
MyTest(1, "B")
MyTest(2, "A")
MyTest(2, "B")
MyTest(3, "A")
MyTest(3, "B")

We're using MSTest now, but is there any equivalent for this so that I can run the same test with multiple parameters?

[TestMethod]
public void Mytest()
{
    // ...
}

Best Answer

EDIT 4: Looks like this is completed in MSTest V2 June 17, 2016: https://blogs.msdn.microsoft.com/visualstudioalm/2016/06/17/taking-the-mstest-framework-forward-with-mstest-v2/

Original Answer:

As of about a week ago in Visual Studio 2012 Update 1 something similar is now possible:

[DataTestMethod]
[DataRow(12,3,4)]
[DataRow(12,2,6)]
[DataRow(12,4,3)]
public void DivideTest(int n, int d, int q)
{
  Assert.AreEqual( q, n / d );
}

EDIT: It appears this is only available within the unit testing project for WinRT/Metro. Bummer

EDIT 2: The following is the metadata found using "Go To Definition" within Visual Studio:

#region Assembly Microsoft.VisualStudio.TestPlatform.UnitTestFramework.dll, v11.0.0.0
// C:\Program Files (x86)\Microsoft SDKs\Windows\v8.0\ExtensionSDKs\MSTestFramework\11.0\References\CommonConfiguration\neutral\Microsoft.VisualStudio.TestPlatform.UnitTestFramework.dll
#endregion

using System;

namespace Microsoft.VisualStudio.TestPlatform.UnitTestFramework
{
    [AttributeUsage(AttributeTargets.Method, AllowMultiple = false)]
    public class DataTestMethodAttribute : TestMethodAttribute
    {
        public DataTestMethodAttribute();

        public override TestResult[] Execute(ITestMethod testMethod);
    }
}

EDIT 3: This issue was brought up in Visual Studio's UserVoice forums. Last Update states:

STARTED · Visual Studio Team ADMIN Visual Studio Team (Product Team, Microsoft Visual Studio) responded · April 25, 2016 Thank you for the feedback. We have started working on this.

Pratap Lakshman Visual Studio

https://visualstudio.uservoice.com/forums/330519-team-services/suggestions/3865310-allow-use-of-datatestmethod-datarow-in-all-unit

Related Solutions

How should I unit test multithreaded code

Look, there's no easy way to do this. I'm working on a project that is inherently multithreaded. Events come in from the operating system and I have to process them concurrently.

The simplest way to deal with testing complex, multithreaded application code is this: If it's too complex to test, you're doing it wrong. If you have a single instance that has multiple threads acting upon it, and you can't test situations where these threads step all over each other, then your design needs to be redone. It's both as simple and as complex as this.

There are many ways to program for multithreading that avoids threads running through instances at the same time. The simplest is to make all your objects immutable. Of course, that's not usually possible. So you have to identify those places in your design where threads interact with the same instance and reduce the number of those places. By doing this, you isolate a few classes where multithreading actually occurs, reducing the overall complexity of testing your system.

But you have to realize that even by doing this, you still can't test every situation where two threads step on each other. To do that, you'd have to run two threads concurrently in the same test, then control exactly what lines they are executing at any given moment. The best you can do is simulate this situation. But this might require you to code specifically for testing, and that's at best a half step towards a true solution.

Probably the best way to test code for threading issues is through static analysis of the code. If your threaded code doesn't follow a finite set of thread safe patterns, then you might have a problem. I believe Code Analysis in VS does contain some knowledge of threading, but probably not much.

Look, as things stand currently (and probably will stand for a good time to come), the best way to test multithreaded apps is to reduce the complexity of threaded code as much as possible. Minimize areas where threads interact, test as best as possible, and use code analysis to identify danger areas.

C# – How to cast int to enum

From an int:

YourEnum foo = (YourEnum)yourInt;

From a string:

YourEnum foo = (YourEnum) Enum.Parse(typeof(YourEnum), yourString);

// The foo.ToString().Contains(",") check is necessary for enumerations marked with an [Flags] attribute
if (!Enum.IsDefined(typeof(YourEnum), foo) && !foo.ToString().Contains(","))
{
    throw new InvalidOperationException($"{yourString} is not an underlying value of the YourEnum enumeration.")
}

Update:

From number you can also

YourEnum foo = (YourEnum)Enum.ToObject(typeof(YourEnum) , yourInt);

Best Answer

Related Solutions

How should I unit test multithreaded code

C# – How to cast int to enum

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