mockhttp VS go-txdb

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.

What is the need to create a wrapper around the HttpClient? If it's for mocking, you can use this MockedHttpClientHandler for you tests

Voilà! That's how to write tests with HttpClient and Moq. With some extension methods, we could have a small DSL to write more readable tests. For a more fully-featured alternative to write tests for HttpClient, check mockhttp, "a testing layer for Microsoft's HttpClient library."

So if you need to mock http client you may want to look into a library like https://github.com/richardszalay/mockhttp

3 years ago I created a internal library where I worked to setup the testing with the db's. One param was the schema directory and the other one was the path of the data insertion file. It worked really well but was a little slow. It was a little bit weird to configure the container to run the tests. As I would have to give access to go container that ran the unit tests access to docker. But back then I was running boot2docker and made things very cumbersome. I think with a local docker things would be way simpler. I ended up using and normal DB from the CI/CD and https://github.com/DATA-DOG/go-txdb If I had to do it again I might do an hybrid in-between the two solutions

The first one is TestMain, which could improve the lifecycle management of the container. The second one is DATA-DOG/go-txdb, this allows you to open a new db connection running in a transaction, so each test could have its own isolated DB connection.