Component Verification

bUnit is a testing library for Blazor that makes it as easy to test components as it is to test a simple C# class.

1. Fast and Headless

Unlike Selenium or Playwright, bUnit doesn't need a real browser. It renders the component in memory and allows you to inspect the markup, trigger events, and verify state changes. var cut = RenderComponent<MyButton>(); cut.Find("button").Click(); Assert.Contains("Clicked", cut.Markup);.

2. Isolated Testing

Because bUnit is so fast, developers actually *write* tests for their UI logic. You can test conditional rendering, loops, and parameter passing in isolation. It's the 'First Line of Defense' against UI regressions in a large Blazor codebase.

3. Architect Insight

Q: "Should I test every HTML tag?"

Architect Answer: "NO. Don't test that a <div> exists. Test the **Logic** inside the UI. Test that a validation message appears if the input is wrong. Test that the 'Submit' button is disabled while an API call is in progress. Focus on the behavior that makes the component functional, not just its appearance."