At the moment I try to establish best practices for unit testing go handlers. I need to mock dependencies, but therefore I have to be able to access / mock these dependencies.
There I some solutions I do not want to consider like for example global variables / application state. Or having all handlers as functions of a struct holding the dependencies member variables.
I was kind of satisfied with a solution where I injected the needed dependencies of a handler in the following way:
func helloHandler(db *DbService) http.HandlerFunc {
return func(w http.ResponseWriter, r *httpRequest) {
// handler code goes here
}
}
Then I am able to provide this handler for routing:
http.HandleFunc("/hello", helloHander(myDbService))
I can also test it easily:
helloHandler(myDbService)(req, respRecorder)
But when I use for example gorilla mux (what I haven't considered from the beginning) I get another problem.
Gorilla/mux adds extra semantics like filtering by Method (GET / POST), providing path parameters etc.
So I should need to test the resulting gorilla router. But then I am again not able to inject my mock dependencies anymore.
When I get the router back everything (dependencies) is already set up.
But I also don't want to rebuild my Router in my tests because of DRY!
So for now I don't really have a good solution for the problem of conveniently setting up my routes but also being able to mock the dependencies.
Any idea?