Added tests to test if addr change command is only given if address is different

test/test_hpib.py

@@ -109,6 +109,18 @@ class PrologixGpibUsbTest(unittest.TestCase):
 
         write_mock.assert_called_with("++addr " + str(address) + chr(10) + command + chr(10))
 
+    def test_command_no_prepend_plusplus_addr_if_address_already_used(self):
+        address = 2
+        command = "command"
+        write_mock = self.serial_mock.return_value.write
+
+        usb = hpib.PrologixGpibUsb()
+
+        usb.command(address, command)
+        usb.command(address, command)
+
+        write_mock.assert_called_with(command + chr(10))
+
     def test_query_prepend_plusplus_addr_if_new_address(self):
         address = 2
         query = "query"
@@ -122,6 +134,19 @@ class PrologixGpibUsbTest(unittest.TestCase):
                                       query + chr(10) +
                                       "++read eoi" + chr(10))
 
+    def test_query_no_prepend_plusplus_addr_if_address_already_used(self):
+        address = 2
+        query = "query"
+        write_mock = self.serial_mock.return_value.write
+
+        usb = hpib.PrologixGpibUsb()
+
+        usb.query(address, query)
+        usb.query(address, query)
+
+        write_mock.assert_called_with(query + chr(10) +
+                                      "++read eoi" + chr(10))
+
 
 if __name__ == '__main__':
     unittest.main()