Presentation integration tests (MCP)

The rule

tests/Presentation.Tests.Integration talks to the whole server the way a real client does. ModelContextProtocolApplication (a WebApplicationFactory<Program>) starts the server with the local environment, its own shared-cache in-memory SQLite database and the sample data on. BaseToolTests connects an McpClient to it over the streamable HTTP transport before each test and disposes both after.

Results are read with Deserialize<T>(), which uses the server's own McpSerializer.Options (json-serialization).

Steps

1. Tool, resource and prompt tests inherit BaseToolTests. Put them in Tools/, Resources/ or Prompts/.
2. Find the rows you need through the server (search, then pick one with the property you need), not by hard-coded ids. Sample data ids are random.
3. For each tool, test the success paths and each error result, asserting the message the model will read (test-design).
4. For resources and prompts, assert the McpProtocolException.ErrorCode (ResourceNotFound, InvalidParams) and its message.
5. A tool's name, title and annotations are checked in ToolListTests; add a row for a new tool.
6. In a solution with authentication, tests that need it create their own ModelContextProtocolApplication with Authentication:* settings and a test signing key, and use a plain HttpClient or a client with a bearer token. See Authentication/AuthenticationTests.cs.

Example

// tests/Presentation.Tests.Integration/Tools/BaseToolTests.cs
protected async Task<T> CallAsync<T>(string name, Dictionary<string, object?>? arguments = null)
{
    var result = await this.Client.CallToolAsync(name, arguments);

    result.IsError.ShouldNotBe(true, result.Content.OfType<TextContentBlock>().FirstOrDefault()?.Text);

    return result.Content.OfType<TextContentBlock>().First().Text.Deserialize<T>();
}

// tests/Presentation.Tests.Integration/Resources/ResourceTests.cs
[Fact]
public async Task ReadMovie_WithUnknownId_ShouldThrow_ResourceNotFound()
{
    // Act
    var exception = await Should.ThrowAsync<McpProtocolException>(() => this.Client.ReadResourceAsync($"movies://{Guid.NewGuid()}").AsTask());

    // Assert
    exception.ErrorCode.ShouldBe(McpErrorCode.ResourceNotFound);
    exception.Message.ShouldContain("The Movie with the supplied id was not found.");
}

Don't

• Share one server across test classes. Each test gets its own server and database.
• Call tool methods directly in an integration test. That's what the unit tests do.
• Build your own JsonSerializerOptions in a test.
• Edit appsettings files for a test. Pass settings.
• Assume a result order the tool doesn't promise.

Check

dotnet test tests/Presentation.Tests.Integration