bUnit Quick Reference

bUnit.razor

@* need to change project SDK *@
<Project Sdk="Microsoft.NET.Sdk.Razor">
  
@* add bUnit package *@
  <PackageReference Include="bunit" Verion="x.x.x" />

@* Use a `@code` block in a `.razor` test file, e.g. *@
  
@* if the test component inherits from `TestContext ` you don't need the `new TestContext();` bit
@code {
 [Fact]
  public void SomeTest()
  {
    // test counter
    using var ctx = new TestContext();
    IRenderedFragment cut = ctx.Render(@<Counter />);
    
    // get button and click it
    IElement button = cut.Find("button");
    button.Click();
  
    IElement paragraph = cut.Find("p");
    paragraph.MarkupMatches(@<p>Current count: 1</p>");
  
    // can also call .Change(..), e.g
    // from pizza workshop
    cut.Find(".toppings-group select").Change("1");
  
    // model is updated:
    Assert.NotEmpty(pizza.Toppings);
    
    // markup verifier is relaxed, order and whitespace not important
    // when using .MarkupMatches()
    
    // we can ignore content of an element with 
    <button diff:ignore />
    
    // we can use regex:
    <button id:regex="order-\d{3}" .. />
  
    // can find child component
    var child = cut.FindComponent<ComponentType>();
  
    // can find child component*S*
    var children = cut.FindComponents<ComponentType>();
   
    // check exists:
    cut.HasComponent<ComponentType>();
  
    // see _ComponentFactories_ for creating replacements so you can 
    // ignore child component details
  
    // have same Parameters as original, or have `CaptureUnmatchedValues`
  }
}