Override Autofac registration - Integration tests with DI

Question

I write integration tests for my application, and use my container for this. I want to be able to register all the components as I do in real running, and then override some

Answer 1

Autofac will use the last registered component as the default provider of that service

From the AutoFac documation.

In your arrange/setup/testInit phase register the mocks, then resolve the SUT:

[SetUp]
public void TestInit()
{
    Mock mock = new Mock();
    builder.RegisterInstance(mock.object).As();
    ...
    ...
    _target = builder.Resolve();
}

Note:

Singletons, static members and SingletonLifestyle(registration) may cause some troubles....