July 2017 – LearnC#WithDarko

Parameterizing Unit Tests using xUnit

xUnit allows our unit test to use parameters, which allows us to test our code for multiple scenarios without needing to write multiple methods with same content.

Let’s look at example from previous lesson

[Fact]
public void ShouldReturnSumOfValues()
   {
	Program prog = new Program();
	int addingResult = prog.Add(3, 9);

	Xunit.Assert.Equal(12, addingResult);
   }

[Fact]

public void ShouldReturnSumOfValues()

{

Program prog = new Program();

int addingResult = prog.Add(3, 9);

Xunit.Assert.Equal(12, addingResult);

}

Here we test if 3 + 9 equals 12.

But what if we wanted to test our Add method for multiple scenarios?

We could use InlineData Attribute.

InlineData Attribute allows us to run our test with input parameters, and passes those parameters to test method using params object[] data.

[Fact]
[InlineData(15,5,10)][InlineData(15,5,10)]
[InlineData(55, 4, 51)]
[InlineData(99, 33, 66)]
public void ShouldReturnSumOfValues(int result, 
	int valueOne, int valueTwo)
{
	Program prog = new Program();
	int addingResult = prog.Add(valueOne, valueTwo);

	Xunit.Assert.Equal(result, addingResult);
}

[Fact]

[InlineData(15,5,10)][InlineData(15,5,10)]

[InlineData(55, 4, 51)]

[InlineData(99, 33, 66)]

public void ShouldReturnSumOfValues(int result,

int valueOne, int valueTwo)

{

Program prog = new Program();

int addingResult = prog.Add(valueOne, valueTwo);

Xunit.Assert.Equal(result, addingResult);

}

We are not done yet.

Compiler is not happy and we are getting error : Fact methods cannot have parameters.

Simple solution is to replace Fact Attribute with Theory Attribute

[Theory]
[InlineData(15,5,10)][InlineData(15,5,10)]
[InlineData(55, 4, 51)]
[InlineData(99, 33, 66)]
public void ShouldReturnSumOfValues(int result, 
	int valueOne, int valueTwo)
{
	Program prog = new Program();
	int addingResult = prog.Add(valueOne, valueTwo);

	Xunit.Assert.Equal(result, addingResult);
}

[Theory]

[InlineData(15,5,10)][InlineData(15,5,10)]

[InlineData(55, 4, 51)]

[InlineData(99, 33, 66)]

public void ShouldReturnSumOfValues(int result,

int valueOne, int valueTwo)

{

Program prog = new Program();

int addingResult = prog.Add(valueOne, valueTwo);

Xunit.Assert.Equal(result, addingResult);

}

Now, when we run our unit test we can see that same test method ran 3 times an all test have passed 🙂

Also note that we can also see input parameters!

Beginners guide to xUnit

04/07/2017 / Darko / 0 Comments

To add xUnit to your project open up NuGet package manager

(Tools -> NuGet Package manager -> Manage Nuget packages for Solution

Right-click References of your project and chose Manage Nuget packages)

xUnit Nuget installation

And find xUnit package by James Newkirk and Brad Wilson and press install.

To use xUnit in your project you do not have to decorate your class with TestClass attribute!

You must only decorate your methods with Fact Attribute.

Also be sure to reference Xunit assembly in your class file because xUnit’s Assert class is from that namespace.

If tests you write do not show in Test explorer, open NuGet packet manager and add xunit.runner.visualstudio package (do not be confused if you see Visual Studio 2012+ in description, it is just saying that this is for version from VS 2012 an onwards).

There is also neat trick to modify name of your tests. By default Test explorer is showing xUnit’s test names in format Class.Method, but you can only display test Method names. Add new json file to root of project and name it “xunit.runner.json” and open properties of that file and under “Copy to Output Directory” option chose “Copy if newer”.

Open under xunit.runner.json file and under Schema input “https://xunit.github.io/schema/v2.2/xunit.runner.schema.json”, then inside brackets type “methodDisplay”: “method”.

Happy unit testing 🙂

How to create Unit Test with VisualStudio 2017

04/07/2017 / Darko / 0 Comments

This brief tutorial will show you how to create Unit Test with VisualStudio 2017.

There are a few ways to create unit test using VS 2017.

1) Create unit test From the class

Create new Console Application

And in a Program class add public method.

Right click on a method and chose “Create Unit Tests”.

How to add an Unit test project from a class.

Be sure to add a public method because without it you will get an error:

Create Unit Tests is supported only within a public class or a public method

An error is pretty straight forward 🙂

Error you get when adding Unit test project from an empty class or class that has only static members.

Then you can chose additional options or additional Testing frameworks

Unit test options

2) Manually adding a test project

Create new method that returns string with value test.

public string TestResult()
    {
        return "test";
    }

public string TestResult()

{

return "test";

}

Right click solution and add Unit Testing project

Choosing unit test project

Then add an reference to project you wish to unit test

And create a new class ProgramTests

Decorate class with a [TestClass] Attribute

Also add a ShouldReturnTestString void method decorated with a [TestMethod] Attribute

using Microsoft.VisualStudio.TestTools.UnitTesting;

namespace UnitTestingExample.UT
{
    [TestClass]
    public class ProgramTests
    {
        [TestMethod]
        public void ShouldReturnTestString()
        {
            //Arange
            Program prog = new Program();

            //Act
            string result = prog.TestResult();

            //Assert
            Assert.AreNotSame("test", result);
        }
    }
}

using Microsoft.VisualStudio.TestTools.UnitTesting;

namespace UnitTestingExample.UT

{

[TestClass]

public class ProgramTests

{

[TestMethod]

public void ShouldReturnTestString()

{

//Arange

Program prog = new Program();

//Act

string result = prog.TestResult();

//Assert

Assert.AreNotSame("test", result);

}

Be sure to add those Attributes because without them you will not be able to run unit test. Give it a shot.

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MonthJuly 2017

Parameterizing Unit Tests using xUnit

Beginners guide to xUnit

How to create Unit Test with VisualStudio 2017

1) Create unit test From the class

2) Manually adding a test project