NUnit vs xUnit vs MSTest: Which is better? Detailed Comparison
When you build the software, you most likely follow the Software Development Life Cycle (SDLC) process, where testing is the most critical part. The testing phase will go through a separate process called Software Testing Life Cycle (STLC). The testing requires the planning, development, and execution of test cases.
In the modern technology world, testing is carried out at multiple stages such as Unit testing, Integration Testing, API Testing, End to End Testing, etc. Some stages concentrate on data, while some concentrates on functionality. However, when the testing signed off the application or functionality, it’s understood that the testing has been carried out to verify the Data, User Interface, Styles, and End-user functionality.
Test automation is part of testing, which reduces the time required to test or re-test. Also, it has other advantages, such as less cost, resource consumption, and timely delivery. The development architecture and frameworks are evolving, and depending on the project and product, the architecture and programming languages will be chosen. Java, C#, and Python are the most commonly used programming languages. When it comes to automation testing, most organizations prefer to use the same programming languages as development.
C# is the most trending language in the .NET world. Any organization, which prefers the Microsoft tech stack and .NET architecture, typically uses C# programming language. Like Java and Python, C# also has many testing frameworks to support automation testing at different stages. NUnit, xUnit, and MSTest are popular testing tools with the .NET framework. Understanding the differences and their features helps to choose the right one for your project. If we look through C# history, it has evolved and shares a lot of similarities with Java. Similarly, the testing tools also share a lot of similarities in comparison with Java-based testing tools.
The NUnit, xUnit, and MSTest are the top trending testing frameworks that are used with C# programming languages. Most of the time organization doesn’t want to spend much on testing tools, so open-source tools are preferred. Similarly, when it comes to testing tools, you need to consider the features such as cross-platform support, data-driven testing support, extensibility, customization, reporting, learning curve, documentation, community support, etc.
Let’s compare the top 3 testing frameworks NUnit, xUnit, and MSTest, and understand their features and differences.
Table Of Contents
NUnit Testing Tool
The NUnit is adapted from Java JUnit, so users feel a similar flavor while using it. It is a free testing framework for all .NET based languages. NUnit is shipped with an MIT license; it is open-source, and .NET Foundation supports it. The latest NUnit 3 is completely rewritten to support many new features.
The NuGet is the package manager for .NET framework. The NuGet keeps track of the download history. The trends show that NuGet is downloaded 216M with an average of 50K per day downloads. The current version of NUnit is 3.13.X.
NUnit GitHub Trends
License: MIT license
Used by: 212K
Contributors: 186
Stars: 2.3K
Features of NUnit
- Easy to learn
- Easy to switch from JUnit to NUnit as many features are similar
- The large set of annotations makes coding easy and execution faster.
- Data-driven testing support
- Supports for Unit, Integration, and end-to-testing (E2E with third-party testing tools such as Selenium, Playwright, etc.)
- Parallel test execution support
- Debugging support.
- Development-friendly, test cases can be executed using the console or the GUI tool, which is available as a plugin for Visual Studio.
- Good Community support
NUnit Annotations
The annotations are also called attributes in NUnit terminology. There are nearly 40+ different types of annotation available; you can use them as per your requirements. Let’s explore the most commonly used and important attributes.
| Annotation | Description |
| [TestFixture] | The text fixtures mark the class as that contains tests |
| [OneTimeSetUp] | The OneTimeSetUp methods are called once per fixture before the start of any tests. It is a fixture-level attribute. |
| [OneTimeTearDown] | This method is called once after all test execution is completed in the test fixture |
| [SetUp] | This method is called once per test before starting the test. |
| [TearDown] | This method is called once per each test after completing the test. |
| [Test] | Attribute marks method as a test method; this is the place where your actual test will be written |
| [Ignore] | Marks the test as ignore or skip |
| [TimeOut] | The timeout value for test cases in execution |
| [Retry] | Re-runs the test cases |
| [TestCase] | Marks the method as a test and also passes the inline parameters for parameterized tests |
| [Random] | The random value will be passed for parameterized tests |
| [ExpectedException(ExceptionType)] | Marks a test method expected to throw a particular Exception Type |
xUnit Testing Library
xUnit is Open source test library for .NET-based applications. xUnit is written by the same NUnit authors, with better architecture and framework in mind. xUnit is not limited to C#; it can be used for any .NET family language such as F#, VB.Net, etc. xUnit is shipped with Apache 2 license.
The NuGet package manager trends show that xUnit has 268M downloads with an average per day download of 70K. The current xUnit version is 2.4.X.
xUnit is designed to eliminate the bad testing practices and flaws in NUnit. As the testing tools evolve and extend to a new feature, they deviate from their original goal. xUnit.net author considered every piece of information and created a new highly customizable and extendable framework.
In comparison with all available testing tools for the .NET framework, the xUnit is highly customizable and has the most robust architecture. This is one of the reasons the xUnit is used by many compared to other testing tools.
xUnit GitHub Trends
License: Apache 2.0
Used by: 252K
Contributors: 124
Stars: 3.5K
Features of xUnit
- Highly customizable framework
- Easy to extend the framework libraries such as assertions and annotations
- Runs test methods in an isolated mechanism
- No Setup and TearDown; instead, use the constructor and dispose, which helps to reduce code duplication
- Helps to get rid of the generic way of expected exceptions
- Improved assertion technique to remove the bad practices in testing
- Good community support
xUnit Annotations
| Annotations | Description |
| [Fact] | Marks the method as a test, where your actual test is written |
| [Theory] | Helpful to execute data-driven test cases. Users can use either Fact or Theory based on the type of tests |
| [Trait] | Set arbitrary meta-data on a test |
| [InlineData] | Set the data for parameterized tests and must be used in combination with [Theory] |
| [ClassData] | Used when the parameters being passed to the [Theory] tests are not constants |
| [MemberData] | Used to fetch data for [Theory] from a static method |
Points to remember when using xUnit
Since xUnit has different architecture and syntaxes in comparison with other tools available in the market, it may be challenging to find the right annotations.
- There is no [SetUp]. Instead, the constructor is used to set up the tests.
- There is no [TearDown] annotation; instead the IDisposable.Dispose is used for clean-up steps.
- The expected exception is no longer valid in xUnit. Instead, use the Assert. Throws to verify the exception.
- [OneTimeSetUp] and [OneTimeTeardown] are not available in xUnit; instead, use the IClassFixture<T> and implement the same.
- [Ignore] is not available in xUnit. It provides a skip option for Facts [Fact(Skip=”reason”)].
MSTest Testing Tool
MSTest was developed by Microsoft and then integrated into Visual Studio IDE. MSTest is also available as an open-source version which is now popularly known as MSTest V2. Unlike other frameworks, you do not need to download the MSTest or add the package details. The MSTest is shipped as the default testing framework with Visual Studio.
The NuGet package manager trend shows that the MSTest is downloaded 163.8M with a daily average download of 69K. Just like xUnit, the download and usage rate is higher for MSTest.
Features of MSTest
- Open source
- Cross-platform support: Supports for .Net core, .Net with various operating systems Windows, Mac, and Linux
- Supports data-driven testing
- Customizable and easy to extend
- Testing life Cycle annotation can be customized per user requirement
- Self-descriptive annotations example [TestClass] [TestMethod] [TestInitialize] [TestCleanup]
MSTest Annotations
Here are some commonly used MSTest annotations:
| Annotations | Description |
| [TestClass] | Marks a class that contains tests |
| [ClassInitialize] | Method will be called once before execution of test in the class |
| [ClassCleanup] | Method will be called once after completion of test in the class |
| [TestInitialize] | Method will be called before each test |
| [TestCleanup] | Method will be called after each test |
| [TestMethod] | Marks the method that contains test |
| [DataTestMethod] | Helps in data driven testing, used to pass the data with [DataRow] |
| [DataRow] | Setting up data for parameterized tests |
| [Ignore] | Skip the execution of particular tests |
| [TestCategory] | Specify the category for tests |
NUnit vs xUnit vs MSTest: Comparing the Unit Testing frameworks
In the above section, you have gone through the detailed view of each testing framework. However, it might be difficult to take a call on which is the better framework. Let’s do a quick side-by-side comparison.
| Criteria | NUnit | xUnit | MSTest |
| Setting Up Tests | [SetUp] | Not available(Use constructor) | [TestInitialize] |
| TearDown Tests | [TearDown] | Not Available(Use Dispose) | [TestCleanup] |
| Marking method as Test | [Test] | [Fact]/[Theory] | [TestMethod]/ [DataTestMethod] |
| One-Time Set up for All Tests in One Class | [OneTimeSetUp] | Not Available(Use IClassFixture<T>) | [ClassInitialize] |
| One-Time Teardown for All Tests in One Class | [OneTimeTearDown] | Not Available(Use IClassFixture<T>) | [ClassCleanup] |
| Collection Fixture Setup and Teardown | Not available | ICollectionFixture<T> | Not Available |
| Ignore or Skip tests | [Ignore(“reason”)] | [Fact(Skip=”reason”)] | [Ignore] |
| Specify the Test category | [Category()] | [Trait(“Category”, “”) | [TestCategory()] |
| Assembly level one-time setup | Not available | Not available | [AssemblyInitialize] |
| Assembly level one time clean up | Not available | Not available | [AssemblyCleanUp] |
NUnit Test Framework Sample Code
Below is the simple code, written using the NUnit testing framework:
Example:
using NUnit.Framework;
using OpenQA.Selenium;
using OpenQA.Selenium.Chrome;
using OpenQA.Selenium.Support.UI;
namespace NUnitExample
{
[TestFixture]
public class NUnitExample
{
private IWebDriver driver;
[Test]
public void navigate() {
homeURL = “https://www.testsigma.com”;
driver.Navigate().GoToUrl(homeURL);
}
[TearDown]
public void TearDownTest()
{
driver.Close();
}
[SetUp]
public void SetupTest()
{
driver = new ChromeDriver();
}
}
}
XUnit Test Framework Sample Code
Below is an example of the xUnit code:
Example:
using System;
using XUnit;
using OpenQA.Selenium;
using OpenQA.Selenium.Chrome;
using OpenQA.Selenium.Support.UI;
namespace xUnitExample
{
public class xUnitDemo : IDisposable
{
private IWebDriver driver;
public xUnitDemo()
{
driver = new ChromeDriver();
}
public void Dispose()
{
driver.Close();
}
[Fact]
public void myTest()
{
homeURL = “https://www.testsigma.com”;
driver.Navigate().GoToUrl(homeURL);
}
}
}
MS Test Framework Example Code
Below is the example of the MSTest sample code
Example:
using System;
using System.Text;
using System.Threading;
using OpenQA.Selenium;
using OpenQA.Selenium.Chrome;
using OpenQA.Selenium.Support.UI;
namespace MsTestExample
{
[TestClass]
public class MSTestDemo
{
private IWebDriver driver;
[TestInitialize]
public void TestInitialize()
{
driver = new ChromeDriver();
}
[TestMethod]
public void myTest()
{
homeURL = “https://www.testsigma.com”;
driver.Navigate().GoToUrl(homeURL);
}
[TestCleanup]
public void TestCleanup()
{
driver.Close();
}
}
}
NUnit vs MSTest vs XUnit: Which is better?
All of the above testing frameworks are the most used, and they’re continuously trying to improve and bring new features. Since all 3 are open source, they provide good community support.
The NuGet trends show that the xUnit has the highest number of downloads; MSTest and NUnit follow subsequently. However, this cannot be deciding factor in choosing the testing library. Every testing library has its advantages and disadvantages, so consideration has to be made by carefully evaluating tools by comparing them against the actual business use cases.
Conclusion
Though we say the above frameworks are trending tools, they require a good amount of technical expertise to build the framework and make your test cases up and running. Testsigma watched this move carefully and the difficulties that testers faced, and built a tool that requires no or less technical knowledge.
Testsigma offers the SAAS platform which requires no coding to design the test cases. One who knows and can write English-like language should be able to design the automation tests, and with a few clicks, you can configure them to run across the platforms and browsers. One of the major advantages is you don’t have to build your custom reports to share with the stakeholder once the test execution is complete; everything is ready for you. You can even share the report links and discuss further on this. This not only helps in speedy delivery but also helps manual testers to contribute and set the automation test cases.
