Improved zeromq.zmq/send-all function

- zeromq.zmq/send-all now behaves well when empty coll is given
- test added for zeromq.zmq/send-all and zeromq.zmq/receive-all
  with req/rep socket pair

Author: sjlnk

src/zeromq/zmq.clj

@@ -219,14 +219,15 @@
         (persistent! new-acc)))))
 
 (defn send-all
-  "Send all data parts to the socket.
-  coll is a seq containing byte arrays."
+  "Send all data parts to the socket. coll is a seq containing byte arrays.
+  Does nothing if coll is empty."
   [^ZMQ$Socket socket coll]
   (loop [[x & xs] coll]
-    (if xs
-      (do (send socket x send-more)
-          (recur xs))
-      (send socket x))))
+    (when x
+      (if xs
+        (do (send socket x send-more)
+            (recur xs))
+        (send socket x)))))
 
 (defn ^ZMQ$Socket set-linger
   "The linger option shall set the linger period for the specified socket. The

test/zeromq/zmq_test.clj

@@ -42,3 +42,18 @@
       (zmq/send-str router "ack")
       (let [actual (zmq/receive-str dealer)]
         (is (= "ack" actual))))))
+
+(deftest receive-all-send-all-test
+  (let [addr "inproc://rxtx-all-test"]
+    (with-open [req (doto (zmq/socket context :req)
+                      (zmq/bind addr))
+                rep (doto (zmq/socket context :rep)
+                      (zmq/connect addr))]
+      (zmq/send-all req [(.getBytes "hello") (.getBytes "world")])
+      (let [msg (zmq/receive-all rep)]
+        (is (= (vec (first msg)) (vec (.getBytes "hello"))))
+        (is (= (vec (second msg)) (vec (.getBytes "world"))))
+        )
+      (zmq/send-all rep [(byte-array[])])
+      (let [msg (zmq/receive-all req)]
+        (is (= (vec (first msg)) []))))))