This is an article which I’ve struggled with for the past few weeks. It started plainly enough trying to write about unit testing in go, but there was a lot of overlap with error handling and a significant portion of that was taking a hard look at the Go2 error handling draft. I’ve written and re-written this article many times, where it morphed from advocating simple assertions in tests to make unit testing easier, to actually having a detailed look at where Go2 error handling falls short.

You might be wondering - especially if you’re just beginning to work with Go, how you might add monitoring to your microservice application. As people with some sort of track record will tell you - monitoring is hard. And what I’m telling you - at least basic monitoring doesn’t need to be. You don’t need to set up a Prometheus cluster to get reporting for your simple applications, in fact, you might not even need external services to add a simple printout of your apps statistics.

After writing two books on the subject (API Foundations in Go and 12 Factor Applications with Docker and Go) and years of writing various Go microservices, I do want to put some thoughts down as to what it takes to write great Go code.

Testing is an important part of software development. Specifically, mocking is a common approach where the developer implements an interface that “mocks” the behaviour of a concrete implementation. Depending on the complexity of the mocked objects, there are many ways you can approach this problem.

A common use case for APIs is to provide authentication middleware, which will let a client make authorized requests to your APIs. Generally, your client performs some sort of authentication, and a session token is issued. Recently, JWT (JSON Web Tokens) are a popular method of providing a session token with an expire time, which doesn’t require some sort of storage to perform validation.

RESTful API principles dictate the way applications send and retrieve data from API services. We will be implementing our RESTful API service using HTTP as the transportation mechanism. We will take a look at how to provide this with the Go standard library, and then review the usage with an update to go-chi/chi.