How to clone a Container to avoid initialization cost for each test case

We create/initialize a separate Container for each test case to be able to completely isolate tests. We’ve tried using a single shared container but Singleton registrations cause leaks between tests (we were able to use a shared Container for some of the tests and these tests did execute faster).

What we need is a very fast Container “clone” operation so that we can keep using Container per test but still have fast tests. This is probably not feasible but I still wanted to create this bug because maybe you’ll have another suggestion for us. Maybe there is a better way to isolate tests and still use a single container. Note that we do run each test case in a separate AsyncScope but as I mentioned above, Singleton objects cause issues.

[dotnetjunkie]

I added an Integration Testing Guide to the Simple Injector documentation. It talks about unit vs integration testing and performance considerations when using a DI Container, and shows a way to reuse the same container instance for the entire test suite. I considered adding information about using a container pool, but that solution is likely only more complex compared to using a single container, while being slower, and providing no additional benefits.

Let me know whether that information is helpful.

[erdalsivri]

Thanks Steven, it is definitely helpful!