Native C# Playwright E2E Testing

Goal

Write end-to-end browser tests in native C# using Microsoft.Playwright.Xunit inside a dedicated E2E test project (*.Tests.E2E).

If Tests for This Use Case / Test Case Already Exist

A diff of the specification change may follow the file path in the arguments. When it is there, it is the definitive list of what changed — work through it change by change. A removed line means the scenario it described was dropped: delete the tests that exist only for it instead of keeping them as passing extras.

Before writing new tests, look in the *.Tests.E2E project for an existing test class covering this use case or test case (e.g. PlaceOrderE2ETest.cs, or any class referencing the UC-XXX / TC-XXX ID). If one exists, update it to match the current specification instead of creating a second class:

• Add tests for scenarios, alternative flows, or Flow rows the spec has gained since the tests were written
• Update existing tests whose expected text, labels, routes, or step order the spec has changed
• Delete tests for scenarios or Flow rows the spec no longer contains
• Leave passing tests the spec still requires untouched
• Update seeded test data and cleanup when the spec's Preconditions or Postconditions changed
• Run the whole test class afterwards, not only the tests you added

Workflow

1. Read Use Case / Test Case Specs:
   • Read docs/use_cases/UC-XXX-*.md or docs/test_cases/TC-XXX-*.md.
   • Check whether E2E tests for this artifact already exist. If they do, follow "If Tests for This Use Case / Test Case Already Exist" above and update them instead of adding a parallel class.
2. Setup Playwright Test Class & Host Server:
   • Inherit from Microsoft.Playwright.Xunit.PageTest.
   • Configure a web application test server fixture (WebApplicationFactory<Program> or custom host fixture) to launch the app automatically on a dynamic port during test execution, or read base URL from configuration (https://localhost:5001).
3. Implement E2E User Journeys:
   • Use web-first locators (GetByRole, GetByLabel, GetByTestId) and async assertions (Expect(...).ToBeVisibleAsync()).
   • Allow Blazor interactive hydration to complete after navigation before interacting with components.

   namespace MyApp.Tests.E2E;
   
   public class PlaceOrderE2ETest : PageTest
   {
       private readonly string _baseUrl;
   
       public PlaceOrderE2ETest(TestServerFixture fixture)
       {
           _baseUrl = fixture.BaseUrl; // Dynamic test host URL or configuration
       }
   
       [Fact]
       public async Task UserCanPlaceOrderSuccessfully()
       {
           await Page.GotoAsync($"{_baseUrl}/place-order");
           await Page.GetByLabel("Quantity").FillAsync("2");
           await Page.GetByRole(AriaRole.Button, new() { Name = "Submit Order" }).ClickAsync();
           await Expect(Page.GetByText("Order Placed Successfully")).ToBeVisibleAsync();
       }
   }

4. Verification:
   • Run dotnet test to execute end-to-end tests against the application.