Mocking the DI Container vs Specific Dependencies in Integration Tests.

In Integration Tests, you spin up the entire application DI container but override specific external dependencies (like databases or APIs) with stubs.

Unlike unit tests (where you mock everything explicitly), integration tests rely on the real DI container to ensure the application wires together correctly. You use features like ConfigureTestServices to replace only the IHttpClientFactory or IDbContext with a test double, leaving the rest of the graph intact.