HTTP integration tests

Question

I have a small service written in Go. I'm already testing it with httptest et al, but, I'm mocking the database and etc...

What I would like to do:

• Start up the very same server I use in production with an empty database
• Run tests against it using HTTP
• Get the coverage of those tests

The empty database part is not a problem, since I made everything configurable via environment variables.

Make requests to it is also not the problem, as it is just standard Go code...

The problem is: I don't know how to start the server in a way that I could measure the coverage of it (and it's sub-packages). Also, the main server code is inside a main function... I don't even know if I can call it from somewhere else (I tried the standard way, but not with reflection and stuff like that).

I'm kind of new using Go, so, this I might be talking nonsense.

Answer 1

You can start the http server in your test, and make requests against it.

For more convenience, you can use httptest.Server in the test, and give it your primary http.Handler. The httptest.Server has some methods to better control to start and stop the server, and provides a URL field to give you the local address of the server.

ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
    fmt.Fprintln(w, "Hello, client")
}))
defer ts.Close()

res, err := http.Get(ts.URL)
if err != nil {
    log.Fatal(err)
}
greeting, err := ioutil.ReadAll(res.Body)
res.Body.Close()
if err != nil {
    log.Fatal(err)
}

fmt.Printf("%s", greeting)