golang how to live test an http server?

Question

I use gotests, and gorilla mux and I can unit test my http handlefunc handlers, but they do not respond to the proper http request methods as they should under the gorilla m

Answer 1

Use the net/http/httptest.Server type to test with a live server.

func TestIndex(t *testing.T) {
  // Create server using the a router initialized elsewhere. The router
  // can be a Gorilla mux as in the question, a net/http ServeMux, 
  // http.DefaultServeMux or any value that statisfies the net/http
  // Handler interface.
  ts := httptest.NewServer(router)  
  defer ts.Close()

  newreq := func(method, url string, body io.Reader) *http.Request {
    r, err := http.NewRequest(method, url, body)
    if err != nil {
        t.Fatal(err)
    }
    return r
  }

  tests := []struct {
    name string
    r    *http.Request
  }{
    {name: "1: testing get", r: newreq("GET", ts.URL+"/", nil)},
    {name: "2: testing post", r: newreq("POST", ts.URL+"/", nil)}, // reader argument required for POST
  }
  for _, tt := range tests {
    t.Run(tt.name, func(t *testing.T) {
        resp, err := http.DefaultClient.Do(tt.r)
        defer resp.Body.Close()
        if err != nil {
            t.Fatal(err)
        }
        // check for expected response here.
    })
  }
}

Although the question uses Gorilla mux, the approach and details in this answer apply to any router that satisfies the http.Handler interface.