dotnet-integration-testing

Integration testing patterns for .NET applications using WebApplicationFactory, Testcontainers, and .NET Aspire testing. Covers in-process API testing, disposable infrastructure via containers, database fixture management, and test isolation strategies.

Version assumptions: .NET 8.0+ baseline, Testcontainers 3.x+, .NET Aspire 9.0+. Package versions for Microsoft.AspNetCore.Mvc.Testing must match the project's target framework major version (e.g., 8.x for net8.0, 9.x for net9.0, 10.x for net10.0). Examples below use Testcontainers 4.x APIs; the patterns apply equally to 3.x with minor namespace differences.

Scope

• In-process API testing with WebApplicationFactory
• Disposable infrastructure via Testcontainers
• .NET Aspire distributed application testing
• Database fixture management and test isolation
• Authentication and authorization test setup

Out of scope

• Test project scaffolding (creating projects, package references) -- see [skill:dotnet-add-testing]
• Testing strategy and test type selection -- see [skill:dotnet-testing-strategy]
• Snapshot testing for verifying API response structures -- see [skill:dotnet-snapshot-testing]