playwright

Basic Page Test

```csharp

[Parallelizable(ParallelScope.Self)]

[TestFixture]

public class BlazorUITests : PageTest

{

private DistributedApplication? _app;

private string? _blazorUrl;

[OneTimeSetUp]

public async Task OneTimeSetUp()

{

var appHost = await DistributedApplicationTestingBuilder

.CreateAsync();

_app = await appHost.BuildAsync();

await _app.StartAsync();

_blazorUrl = _app.GetEndpoint("blazor-client").ToString();

}

[Test]

public async Task HomePage_LoadsSuccessfully()

{

await Page.GotoAsync(_blazorUrl!);

await Page.WaitForLoadStateAsync();

await Expect(Page).ToHaveTitleAsync(new Regex("Sorcha|Blueprint"));

}

}

```

Locator Patterns

```csharp

// Role-based (preferred)

await Page.GetByRole(AriaRole.Button, new() { Name = "Submit" }).ClickAsync();

// Text-based

Page.Locator("a:has-text('Designer')")

// MudBlazor components

Page.Locator(".mud-button")

Page.Locator(".mud-table")

// Test IDs (most stable)

Page.Locator("[data-testid='my-element']")

```

| Concept | Usage | Example |

|---------|-------|---------|

| PageTest | Base class providing Page object | class MyTests : PageTest |

| Locator | Lazy element reference | Page.Locator("button") |

| Expect | Assertion API | await Expect(Page).ToHaveURLAsync(...) |

| Aspire Testing | Full stack integration | DistributedApplicationTestingBuilder |

| Auto-wait | Built-in waiting | Actions wait for actionability |

JavaScript Error Detection

```csharp

[Test]

public async Task NoJavaScriptErrors()

{

var errors = new List();

Page.Console += (_, msg) =>

{

if (msg.Type == "error") errors.Add(msg.Text);

};

await Page.GotoAsync(_blazorUrl!);

await Page.WaitForLoadStateAsync();

var criticalErrors = errors.Where(e =>

!e.Contains("WASM") && !e.Contains("Blazor")).ToList();

Assert.That(criticalErrors, Is.Empty);

}

```

Responsive Design Testing

```csharp

[Test]

public async Task ResponsiveDesign_Works()

{

await Page.SetViewportSizeAsync(375, 667); // Mobile

await Page.GotoAsync(_blazorUrl!);

Assert.That(await Page.TextContentAsync("body"), Is.Not.Empty);

await Page.SetViewportSizeAsync(1920, 1080); // Desktop

await Page.ReloadAsync();

Assert.That(await Page.TextContentAsync("body"), Is.Not.Empty);

}

```

• [patterns](references/patterns.md) - Locator strategies and assertions
• [workflows](references/workflows.md) - Test setup and CI integration

• See the xunit skill for unit testing patterns
• See the fluent-assertions skill for SignalR integration tests
• See the blazor skill for component architecture
• See the signalr skill for real-time notification testing
• See the docker skill for container-based test environments

> Fetch latest Playwright .NET documentation with Context7.

How to use Context7:

1. Use mcp__context7__resolve-library-id to search for "playwright"
2. Prefer website documentation (/websites/playwright_dev_dotnet) over source code
3. Query with mcp__context7__query-docs using the resolved library ID

Library ID: /websites/playwright_dev_dotnet

Recommended Queries:

• "Locators selectors best practices"
• "NUnit test fixtures setup teardown"
• "Wait for element network idle auto-waiting"
• "Assertions expect API"
• "Trace viewer debugging"