Unit Testing

Unit Testing

Making cache transparent with FakeCache

CleverCache ships with a FakeCache implementation that never caches — it always calls through to the underlying factory. This makes your service logic fully testable without the cache getting in the way.

using CleverCache;

var mocker = new AutoMocker();
mocker.Use<ICleverCache>(new FakeCache());
var sut = mocker.CreateInstance<OrderService>();

// Tests run as normal — the factory is always called, cache is invisible
var result = await sut.GetAllOrdersAsync();

FakeCache is in the root CleverCache namespace — no additional using directives needed beyond what you'd normally import.

Verifying cache interactions with Mock<ICleverCache>

If you need to assert how the cache was used — for example, that the factory was called exactly once, or that a specific key was evicted — use a mock instead:

var cacheMock = new Mock<ICleverCache>();
cacheMock
    .Setup(c => c.GetOrCreateAsync(
        It.IsAny<Type[]>(),
        It.IsAny<object>(),
        It.IsAny<Func<Task<List<Order>>>>(),
        null))
    .ReturnsAsync(new List<Order>());

var sut = new OrderService(cacheMock.Object, db);
await sut.GetAllOrdersAsync();

cacheMock.Verify(c => c.GetOrCreateAsync(...), Times.Once);

ICleverCache is a plain interface and works with any mocking library (Moq, NSubstitute, FakeItEasy, etc.).

MediatR and [AutoCache]

If you are only using MediatR automatic caching via [AutoCache] and never injecting ICleverCache directly into your services, you don't need FakeCache at all — the AutoCacheBehaviour pipeline behaviour is never part of your unit test boundary.

For integration tests that exercise the full MediatR pipeline, register FakeCache or an in-memory store in your test service collection.