consumer_test.go

package consumer

import (
	"errors"
	"testing"

	"github.com/bitly/go-nsq"
)

// tests nsq.HandlerFunc. just write the function in line in the test
// itself
func TestHandlerFunc(t *testing.T) {
	testPayload := "this is a test"
	msg := generateMessage(testPayload)
	f := nsq.HandlerFunc(func(message *nsq.Message) error {
		if string(message.Body) != testPayload {
			return errors.New("payload didn't match")
		}
		return nil
	})

	err := f(msg)
	if err != nil {
		t.Fatal("handlerfunc didn't work!", err)
	}
}

// or if you have a special handler type, do it this way. for this
// purpose, just a simple struct with a testing object for context.
type MyHandler struct {
	expectedMessage string
	t               *testing.T
}

// and the HandleMessage func will use that object to log something
func (h *MyHandler) HandleMessage(message *nsq.Message) error {
	if string(message.Body) != h.expectedMessage {
		return errors.New("payload didn't match")
	}
	h.t.Log("i'm in MyHandler.HandleMessage!")
	return nil
}

// tests MyHandler
func TestMyHandler(t *testing.T) {
	testPayload := "this is another test"
	msg := generateMessage(testPayload)
	mh := &MyHandler{expectedMessage: testPayload, t: t}
	err := mh.HandleMessage(msg)
	if err != nil {
		t.Fatal("handler didn't work!", err)
	}
}

func generateMessage(payload string) *nsq.Message {
	id := "1234567890asdfgh"
	var i [nsq.MsgIDLength]byte
	copy(i[:], id)
	return nsq.NewMessage(i, []byte(payload))
}