changed ErrUnknown to ErrEmptyQueue (the real error state in the empty queue Peek state)

Author: Mike Atlas

queue/error.go

@@ -26,6 +26,7 @@ var (
 	// ErrTimeout is returned when an applicable queue operation times out.
 	ErrTimeout = errors.New(`queue: poll timed out`)
 
-	// ErrUnknown is returned if the error state was unusual and unexpected.
-	ErrUnknown = errors.New(`queue: unknown error`)
+	// ErrEmptyQueue is returned when an non-applicable queue operation was called
+	// due to the queue's empty item state
+	ErrEmptyQueue = errors.New(`queue: empty queue`)
 )

queue/queue.go

@@ -260,11 +260,11 @@ func (q *Queue) Peek() (interface{}, error) {
 	}
 
 	peekItem, ok := q.items.peek()
-	if ok {
-		return peekItem, nil
+	if !ok {
+		return nil, ErrEmptyQueue
 	}
 
-	return nil, ErrUnknown
+	return peekItem, nil
 }
 
 // TakeUntil takes a function and returns a list of items that