bUnit - a testing library for Blazor components

bUnit is a testing library for Blazor Components. Its goal is to make it easy to write comprehensive, stable unit tests. You can:

• Setup and define components under tests in C# or Razor syntax
• Verify outcome using semantic HTML comparer
• Interact with and inspect components
• Trigger event handlers
• Provide cascading values
• Inject services
• Mock IJsRuntime
• Perform snapshot testing

bUnit builds on top of existing unit testing frameworks such as xUnit, NUnit, and MSTest, which runs the Blazor components tests, just as any normal unit test.

Go to the Documentation pages to learn more.

Note

The documentation is currently being rewritten to reflect the recent changes. Please excuse the mess.

Test example

For example, to test the <Counter> component listed below:

<h1>Counter</h1>

<p>
    Current count: @currentCount
</p>

<button class="btn btn-primary" @onclick="IncrementCount">Click me</button>

@code {
  int currentCount = 0;

  void IncrementCount()
  {
    currentCount++;
  }
}

You can do the following, using bUnit and xUnit:

[Fact]
public void CounterShouldIncrementWhenClicked()
{
  // Arrange: render the Counter.razor component
  var cut = RenderComponent<Counter>();

  // Act: find and click the <button> element to increment
  // the counter in the <p> element
  cut.Find("button").Click();

  // Assert: first find the <p> element, then verify its content
  cut.Find("p").MarkupMatches("<p>Current count: 1</p>");
}

NuGet downloads

bUnit is available on NuGet in various incarnations. If you are using xUnit as your general purpose testing framework, you can use bunit, which includes everything in one package. If you want to use NUnit or MStest, then pick bunit.core and bunit.web:

Name	Type	NuGet Download Link
bUnit	Library, includes core, web, and xUnit
bUnit.core	Library, only core
bUnit.web	Library, web and core
bUnit.xUnit	Library, xUnit and core
bUnit.template	Template, which currently creates an xUnit based bUnit test projects only

Milestones to v1.0.0

These are the current goals that should be reached before v1.0.0 is ready:

• Stabilize the APIs, such that they work equally well with both xUnit, NUnit, and MSTest as the underlying test framework. The general goals is to make it easy and obvious for developers to create the tests they needed, and fall into the pit of success.
• Get the Razor-based testing to stable, e.g. make the discovery and running of tests defined in .razor files stable and efficient. This includes adding support for NUnit and MSTest as test runners.
• Improve the documentation. Currently there are a list of "How to" guides planned in the Update Docs milestone.
• Join the .NET Foundation.. This project is too large for one person to be the owner and be the sole maintainer of, so the plan is to apply for membership as soon as possible, most likely close to or after v1.0.0 ships, and get the needed support and guidance to ensure the project long term.

In the post v1.0.0 to v1.0.x time frame, focus will be on improving performance. Especially the spin-up time of about one second would be nice to get reduced.

Contributors

Shout outs and a big thank you to all the contributors to the library, both those that raise issues, provide input to issues, and those who send pull requests.

Want to help out? You can help in a number of ways:

• Provide feedback and input through issues, Twitter or bUnit Gitter chat room.
• Help build the library, just pick an issue and submit pull-requests.
• Help write documentation.
• Create blog posts, presentations or video tutorials. If you do, I will be happy to showcase them in the related section on this site.