golang大猩猩/ mux和测试，在哪里存储路由

Question

In most of the docs I have seen, gorilla mux is suggested to be used like so...

func main() {
    m := mux.Router()
    m.HandleFunc("/", FuncNameOrDef)
    http.ListenAndServe(":8080", m)
}

which is great, but it leaves me with a problem, because then in order to test, as far as I can see, I need to redeclare mux and routes unless I declare mux and routes outside of a function like this...

var (
    m = mux.Router()
    _ = m.HandleFunc("/", FuncNameOrDef)
)

and then in my tests do this...

func TestSomeView(t *testing.T) {
    ts := httptest.NewServer(m)
    ....testing blah
}

which solves the problem, but then it makes the package pretty ugly (with all the _ = m.HandleFunc's) Is there a more idiomatic way to do this?

Answer 1

You could use a factory function to create a new http.Handler for you application. This would allow you to programmatically define the handlers and reuse them in the tests.

// NewApplicationHandler provides a configured handler for the
// application.
func NewApplicationHandler() http.Handler {
    mux := mux.NewRouter()
    mux.HandleFunc("/", handler)

    return mux
}

func handler(w http.ResponseWriter, r *http.Request) {
    w.Write([]byte("Hello World!"))
}

This example would be utilized in a test like so:

func TestApplicationServeMux(t *testing.T) {
    // The handlers are being obtained via a call to the factory function.
    applicationHandler := NewApplicationHandler()

    ts := httptest.NewServer(applicationHandler)
    defer ts.Close()

    res, err := http.Get(ts.URL)

    if err != nil {
        t.Fatalf("%s", err)
    }

    defer res.Body.Close()
    greeting, err := ioutil.ReadAll(res.Body)

    if err != nil {
        log.Fatalf("%s", err)
    }

    want := []byte("Hello World!")

    if !bytes.Equal(want, greeting) {
        t.Errorf("Expected greeting %s; got %s", want, greeting)
    }

}