WireMock.Net VS FsCheck

I'd say that without wanting to refactor the code a little bit (maybe moving those HttpClients into a service so that they are easily mocked) your best bet would be to use something like WireMock or MockHttp.

WireMock

WiremockNet https://github.com/WireMock-Net/WireMock.Net

In this post, I'll explain how to create mocks for HTTP APIs in narrow integration tests using the WireMock.Net library.

Recently was pointed to WireMock for testing purposes.

I use WireMock (@ Java) to start a local webserver alongside the tests, this webserver will provide ‘real’ responses to the client. Here’s the C# equivalent: https://github.com/WireMock-Net/WireMock.Net

You could try out WireMock.Net: https://github.com/WireMock-Net/WireMock.Net/wiki/Using-WireMock-in-UnitTests

Use WireMock to mock responses from the endpoint that FooClient interacts with. This lets you exercise all of the code contained in FooClient in a realistic way, without using mocks, but still get the different responses you expect.

As you can see from the imports statement we're relying on FsCheck to generate some random values for us.

C# - FsCheck

https://fscheck.github.io/FsCheck/ can hopefully generate random inputs automatically or with low effort for many methods to get your code coverage up. You don’t even need to write real tests right now, just call the methods with the random inputs and check they don’t fail.

Try using F# for tests. It has some great libraries like FsCheck (https://fscheck.github.io/FsCheck/).

At Symbolica we're building a symbolic execution service that explores every reachable state of a user's program and verifies assertions at each of these states to check that the program is correct. By default it will check for common undefined behaviours, such as out-of-bounds memory reads or divide by zero, but it can also be used with custom, application specific, assertions too just like the kind you'd write in a unit test. Seen from this perspective it's kind of like FsCheck (or Haskell's QuickCheck or Python's Hypothesis), but much more exhaustive and without the randomness.

Maybe something like QuickCheck, a quick search gave me this library for .NET https://github.com/fscheck/FsCheck

Because of the above I've generally been using tools like Stryker.NET and FsCheck to augment my testing suite. I'm still doing unit testing to find the more obvious "I haven't had my coffee, let's make sure I'm doing what I think I'm doing" bugs. I'm just using things like mutation testing, property testing, fuzzing, etc. to find the deeper issues in my code. There's a ton of libraries out there, including one that I've built for myself to help with testing but FsCheck and Stryker are just beautiful. And if you're interested in fuzzing, SharpFuzz is a great option. But that one isn't quite as easy of an on ramp compared to the other two that I mentioned.

Looks cool. Is there a reason why you didn't use FsCheck or Hedgehog? They're built to generate random data for testing, and can return the seed if a test fails so you can rerun the test with the exact same data once you figure out what the problem is - which is useful if the failure condition is rare.

Haskell has QuickCheck and Hedgehog, and dotnet has both as well. F# is favored, but there's C# interop.

Side note, if you are thinking about testing in general, might be interested in property based testing. See for example https://fscheck.github.io/FsCheck/