msgpack: add test

Signed-off-by: Jack Nagel <jacknagel@gmail.com>

Formula/msgpack.rb

@@ -13,4 +13,44 @@ class Msgpack < Formula
     system "./configure", "--disable-dependency-tracking", "--prefix=#{prefix}"
     system "make install"
   end
+
+  def test
+    # Reference: http://wiki.msgpack.org/display/MSGPACK/QuickStart+for+C+Language
+    mktemp do
+      (Pathname.pwd/'test.c').write <<-EOS.undent
+        #include <msgpack.h>
+        #include <stdio.h>
+
+        int main(void)
+        {
+           msgpack_sbuffer* buffer = msgpack_sbuffer_new();
+           msgpack_packer* pk = msgpack_packer_new(buffer, msgpack_sbuffer_write);
+           msgpack_pack_int(pk, 1);
+           msgpack_pack_int(pk, 2);
+           msgpack_pack_int(pk, 3);
+
+           /* deserializes these objects using msgpack_unpacker. */
+           msgpack_unpacker pac;
+           msgpack_unpacker_init(&pac, MSGPACK_UNPACKER_INIT_BUFFER_SIZE);
+
+           /* feeds the buffer. */
+           msgpack_unpacker_reserve_buffer(&pac, buffer->size);
+           memcpy(msgpack_unpacker_buffer(&pac), buffer->data, buffer->size);
+           msgpack_unpacker_buffer_consumed(&pac, buffer->size);
+
+           /* now starts streaming deserialization. */
+           msgpack_unpacked result;
+           msgpack_unpacked_init(&result);
+
+           while(msgpack_unpacker_next(&pac, &result)) {
+               msgpack_object_print(stdout, result.data);
+               puts("");
+           }
+        }
+        EOS
+
+      system ENV.cc, "-o", "test", "test.c", "-lmsgpack"
+      `./test` == "1\n2\n3\n"
+    end
+  end
 end