add test

main.go

@@ -3,6 +3,7 @@ package main
 import (
 	"encoding/json"
 	"net/http"
+	"strconv"
 )
 
 const (
@@ -21,6 +22,15 @@ func main() {
 	mux.HandleFunc("/version", func(w http.ResponseWriter, r *http.Request) {
 		json.NewEncoder(w).Encode(map[string]string{"version": version})
 	})
+	mux.HandleFunc("/sum", func(w http.ResponseWriter, r *http.Request) {
+		a, _ := strconv.Atoi(r.URL.Query().Get("a"))
+		b, _ := strconv.Atoi(r.URL.Query().Get("b"))
+		json.NewEncoder(w).Encode(map[string]int{"result": sum(a, b)})
+	})
 
 	http.ListenAndServe(":8080", mux)
 }
+
+func sum(a, b int) int {
+	return a + b
+}