Panic for unregistered queues (#4)

* Panic for unregistered queues

* Test that getting an unregistered queue panics.

Author: khawa-angx

queue.go

@@ -125,5 +125,9 @@ func (q *queues) add(queue Queue) {
 func (q *queues) get(name string) Queue {
 	q.RLock()
 	defer q.RUnlock()
-	return q.registry[name]
+	val, ok := q.registry[name]
+	if !ok {
+		panic(fmt.Sprintf("queue '%s' not registered, ensure all queues are registered before calling Client.Start()", name))
+	}
+	return val
 }

queue_test.go

@@ -2,6 +2,8 @@ package backlite
 
 import (
 	"context"
+	"fmt"
+	"strings"
 	"testing"
 )
 
@@ -14,3 +16,19 @@ func TestQueue_CannotDecode(t *testing.T) {
 		t.Error("Process should have failed")
 	}
 }
+
+func TestQueues_GetUnregisteredQueuePanics(t *testing.T) {
+	s := &queues{}
+
+	defer func() {
+		if r := recover(); r == nil {
+			t.Errorf("Should be panicking, but it didn't")
+		} else {
+			if msg, ok := r.(string); !ok || !strings.Contains(msg, fmt.Sprintf("queue '%s' not registered", testTask{}.Config().Name)) {
+				t.Errorf("Unexpected panic value: %v", r)
+			}
+		}
+	}()
+
+	s.get(testTask{}.Config().Name)
+}