Simple Go HTTP Test

main.go

package main

import (
	"fmt"
	"net/http"
)

func IndexHandler(w http.ResponseWriter, r *http.Request) {
	fmt.Fprint(w, "Hello World")
}

func main() {
	http.HandleFunc("/", IndexHandler)

	http.ListenAndServe(":80", nil)
}

main_test.go

package main

import (
	"io/ioutil"
	"net/http"
	"net/http/httptest"
	"testing"
)

func TestIndexHandler(t *testing.T) {
	w := httptest.NewRecorder()
	r := httptest.NewRequest(http.MethodGet, "/", nil)

	IndexHandler(w, r)

	resp := w.Result()
	body, _ := ioutil.ReadAll(resp.Body)

	//fmt.Println(resp.StatusCode)
	//fmt.Println(resp.Header.Get("Content-Type"))
	//fmt.Println(string(body))

	got := string(body)
	want := "Hello World"

	if got != want {
		t.Errorf("got %q, wanted %q", got, want)
	}

	if resp.StatusCode != 200 {
		t.Errorf("Status was not 200, got %q instead", resp.StatusCode)
	}
}