Simple KV API in golang

simdatabase.go

package main

import (
	"fmt"
	"net/http"
	"sync"
)

var (
	KeyMap = map[string]string{}
	RWLock sync.RWMutex
)

func getHandler(w http.ResponseWriter, r *http.Request) {
	if r.Method != "GET" {
		http.Error(w, "Method not implemented", http.StatusBadRequest)
		return
	}

	// RWLock reads
	RWLock.RLock()
	defer RWLock.RUnlock()

	err := r.ParseForm()
	if err != nil {
		http.Error(w, "error parsing form", http.StatusInternalServerError)
		return
	}
	k, ok := r.Form["key"]
	if !ok || len(k) != 1 {
		http.Error(w, "No keyname or multiple keyname to return", http.StatusBadRequest)
		return
	}

	key := k[0]

	value, ok := KeyMap[key]
	if !ok {
		http.Error(w, "Empty key", http.StatusNotFound)
		return
	}
	fmt.Fprintf(w, "%s\n", value)
}

func setHandler(w http.ResponseWriter, r *http.Request) {
	if r.Method != "GET" {
		http.Error(w, "method not implemented", http.StatusBadRequest)
		return
	}

	// Lock for writes
	RWLock.Lock()
	defer RWLock.Unlock()

	err := r.ParseForm()
	if err != nil {
		http.Error(w, "error parsing form", http.StatusInternalServerError)
		return
	}

	for k, v := range r.Form {
		KeyMap[k] = v[0]
		fmt.Fprintf(w, "set key %s as %s\n", k, v[0])
	}
}

func main() {
	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
		http.Error(w, "404 try /set, /get", http.StatusNotFound)
	})

	http.HandleFunc("/get", getHandler)
	http.HandleFunc("/set", setHandler)

	fmt.Println("starting server...")
	http.ListenAndServe(":4000", nil)
}

simdatabase_test.go

package main

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

func TestGetEmpty(t *testing.T) {
	req, _ := http.NewRequest("GET", "get?key=empty", nil)

	rec := httptest.NewRecorder()
	getHandler(rec, req)

	if rec.Code != 404 {
		t.Error("Non empty response for empty key")
	}
}

func TestSetGet(t *testing.T) {
	req, _ := http.NewRequest("GET", "/set?hello=world", nil)

	setRec := httptest.NewRecorder()
	setHandler(setRec, req)

	if setRec.Code != 200 {
		t.Error("failed seting value, got return:", setRec.Code)
	}

	req, _ = http.NewRequest("GET", "/get?key=hello", nil)
	getRec := httptest.NewRecorder()
	getHandler(getRec, req)

	data, err := ioutil.ReadAll(getRec.Body)
	if err != nil {
		t.Error("error while reading get response!", err)
	}

	if bytes.Compare(data, []byte("world\n")) != 0 {
		t.Errorf("get expected: hello=world got hello=%s\n", data)
	}
}