Most Complete MSTest Unit Testing Framework Cheat Sheet

An essential part of every UI test framework is the usage of a unit testing framework. One of the most popular ones in the .NET world is MSTest. However, you cannot find a single place where you can get started with its syntax. So, I decided that it would be great to create a complete cheat sheet.  I hope that you will find it useful. Enjoy!

Download Most Complete MSTest Cheat Sheet PDF

Installation

Install-Package MSTest.TestFramework
Install-Package MSTest.TestAdapter
Install-Package Microsoft.NET.Test.Sdk

Initially, I created the cheat sheet while we developed the first versions of the BELLATRIX automated testing framework. Мost of the stuff in it are still relevant.

Test Execution Workflow

using Microsoft.VisualStudio.TestTools.UnitTesting;
namespace MSTestUnitTests
{
    // A class that contains MSTest unit tests. (Required)
    
    public class YourUnitTests
    {
        
        public static void AssemblyInit(TestContext context)
        {
            // Executes once before the test run. (Optional)
        }
        
        public static void TestFixtureSetup(TestContext context)
        {
            // Executes once for the test class. (Optional)
        }
        
        public void Setup()
        {
            // Runs before each test. (Optional)
        }
        
        public static void AssemblyCleanup()
        {
            // Executes once after the test run. (Optional)
        }
        
        public static void TestFixtureTearDown()
        {
            // Runs once after all tests in this class are executed. (Optional)
            // Not guaranteed that it executes instantly after all tests from the class.
        }
        
        public void TearDown()
        {
            // Runs after each test. (Optional)
        }
        // Mark that this is a unit test method. (Required)
        
        public void YouTestMethod()
        {
            // Your test code goes here.
        }
    }
}

Attributes

Comparing MSTest to other frameworks.

Data Driven Test Attributes

[DataRow(0, 0)]
[DataRow(1, 1)]
[DataRow(2, 1)]
[DataRow(80, 23416728348467685)]

public void GivenDataFibonacciReturnsResultsOk(int number, int result)
{
    var fib = new Fib();
    var actual = fib.Fibonacci(number);
    Assert.AreEqual(result, actual);
}

Data Driven Test CSV

[DataSource("Microsoft.VisualStudio.TestTools.DataSource.CSV", "TestsData.csv", "TestsData#csv", DataAccessMethod.Sequential)]

public void DataDrivenTest()
{
    int valueA = Convert.ToInt32(this.TestContext.DataRow["valueA"]);
    int valueB = Convert.ToInt32(this.TestContext.DataRow["valueB"]);
    int expected = Convert.ToInt32(this.TestContext.DataRow["expectedResult"]);
}

Data Driven Test Dynamic Data

[DynamicData(nameof(GetData), DynamicDataSourceType.Method)]
public void TestAddDynamicDataMethod(int a, int b, int expected)
{
    var actual = _calculator.Add(a, b);
    Assert.AreEqual(expected, actual);
}
public static IEnumerable<object[]> GetData()
{
    yield return new object[] { 1, 1, 2 };
    yield return new object[] { 12, 30, 42 };
    yield return new object[] { 14, 1, 15 };
}

Assertions

Assert.AreEqual(28, _actualFuel); // Tests whether the specified values are equal.
Assert.AreNotEqual(28, _actualFuel); // Tests whether the specified values are unequal. Same as AreEqual for numeric values.
Assert.AreSame(_expectedRocket, _actualRocket); // Tests whether the specified objects both refer to the same object
Assert.AreNotSame(_expectedRocket, _actualRocket); // Tests whether the specified objects refer to different objects
Assert.IsTrue(_isThereEnoughFuel); // Tests whether the specified condition is true
Assert.IsFalse(_isThereEnoughFuel); // Tests whether the specified condition is false
Assert.IsNull(_actualRocket); // Tests whether the specified object is null
Assert.IsNotNull(_actualRocket); // Tests whether the specified object is non-null
Assert.IsInstanceOfType(_actualRocket, typeof(Falcon9Rocket)); // Tests whether the specified object is an instance of the expected type
Assert.IsNotInstanceOfType(_actualRocket, typeof(Falcon9Rocket)); // Tests whether the specified object is not an instance of type
StringAssert.Contains(_expectedBellatrixTitle, "Bellatrix"); // Tests whether the specified string contains the specified substring
StringAssert.StartsWith(_expectedBellatrixTitle, "Bellatrix"); // Tests whether the specified string begins with the specified substring
StringAssert.Matches("(281)388-0388", @"(?d{3})?-? *d{3}-? *-?d{4}"); // Tests whether the specified string matches a regular expression
StringAssert.DoesNotMatch("281)388-0388", @"(?d{3})?-? *d{3}-? *-?d{4}"); // Tests whether the specified string does not match a regular expression
CollectionAssert.AreEqual(_expectedRockets, _actualRockets); // Tests whether the specified collections have the same elements in the same order and quantity.
CollectionAssert.AreNotEqual(_expectedRockets, _actualRockets); // Tests whether the specified collections does not have the same elements or the elements are in a different order and quantity.
CollectionAssert.AreEquivalent(_expectedRockets, _actualRockets); // Tests whether two collections contain the same elements.
CollectionAssert.AreNotEquivalent(_expectedRockets, _actualRockets); // Tests whether two collections contain different elements.
CollectionAssert.AllItemsAreInstancesOfType(_expectedRockets, _actualRockets); // Tests whether all elements in the specified collection are instances of the expected type
CollectionAssert.AllItemsAreNotNull(_expectedRockets); // Tests whether all items in the specified collection are non-null
CollectionAssert.AllItemsAreUnique(_expectedRockets); // Tests whether all items in the specified collection are unique
CollectionAssert.Contains(_actualRockets, falcon9); // Tests whether the specified collection contains the specified element
CollectionAssert.DoesNotContain(_actualRockets, falcon9); // Tests whether the specified collection does not contain the specified element
CollectionAssert.IsSubsetOf(_expectedRockets, _actualRockets); // Tests whether one collection is a subset of another collection
CollectionAssert.IsNotSubsetOf(_expectedRockets, _actualRockets); // Tests whether one collection is not a subset of another collection
Assert.ThrowsException<ArgumentNullException>(() => new Regex(null)); // Tests whether the code specified by delegate throws exact given exception of type T

Execute Tests in Parallel

[assembly: Parallelize(Workers = 0, Scope = ExecutionScope.MethodLevel)]

Workers- the number of threads to run the tests. Set it to 0 to use the number of core of your computer.

Scope- determine if the runner must parallelise tests at the method or class level. MethodLevel runs all tests in parallel. ClassLevel runs all test classes in parallel, but tests in a class are executed sequentially. You should use ClassLevel if the tests within classes have interdependencies.

If you have multiple test assemblies you want to parallelize you can create a file named .runsettings at the root of the solution:

<?xml version="1.0" encoding="utf-8"?>
<RunSettings>
	<MSTest>
		<Parallelize>
			<Workers>8</Workers>
			<Scope>MethodLevel</Scope>
		</Parallelize>
	</MSTest>
</RunSettings>

Download Most Complete MSTest Cheat Sheet PDF