Implemented unit tests for message printer block
diff --git a/python/CMakeLists.txt b/python/CMakeLists.txt
index cb4b2b2..486ff80 100644
--- a/python/CMakeLists.txt
+++ b/python/CMakeLists.txt
@@ -47,5 +47,6 @@
 set(GR_TEST_TARGET_DEPS gr-gsm)
 set(GR_TEST_PYTHON_DIRS ${CMAKE_BINARY_DIR}/swig)
 GR_ADD_TEST(qa_decryption ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/qa_decryption.py)
+GR_ADD_TEST(qa_message_printer ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/qa_message_printer.py)
 #GR_ADD_TEST(qa_receiver ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/qa_receiver.py)
 #GR_ADD_TEST(qa_receiver_hier ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/qa_receiver_hier.py)
diff --git a/python/qa_message_printer.py b/python/qa_message_printer.py
new file mode 100755
index 0000000..4efaaef
--- /dev/null
+++ b/python/qa_message_printer.py
@@ -0,0 +1,166 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+# @file
+# @author Roman Khassraf <rkhassraf@gmail.com>
+# @section LICENSE
+# 
+# Gr-gsm is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3, or (at your option)
+# any later version.
+# 
+# Gr-gsm is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+# 
+# You should have received a copy of the GNU General Public License
+# along with gr-gsm; see the file COPYING.  If not, write to
+# the Free Software Foundation, Inc., 51 Franklin Street,
+# Boston, MA 02110-1301, USA.
+# 
+# 
+
+from gnuradio import gr, gr_unittest, blocks
+import grgsm
+import os
+import pmt
+import sys
+import tempfile
+
+class qa_message_printer (gr_unittest.TestCase):
+   
+    def setUp (self):
+        self.tb = gr.top_block()
+        self.tmpfile = tempfile.NamedTemporaryFile()
+        self.prevfd = os.dup(sys.stdout.fileno())
+        os.dup2(self.tmpfile.fileno(), sys.stdout.fileno())
+        self.prev = sys.stdout
+        sys.stdout = os.fdopen(self.prevfd, "w")
+        
+    def tearDown (self):
+        self.tb = None
+        os.dup2(self.prevfd, self.prev.fileno())
+        sys.stdout = self.prev
+        self.tmpfile.close()
+        
+    def getOutput(self):
+        self.tmpfile.seek(0)
+        return self.tmpfile.read()
+    
+    def getOutputExpected(self, expected_lines):
+        out = ""
+        for l in expected_lines:
+            out = out + l + "\n"
+        return out
+        
+    def test_001_no_prefix_no_header (self):
+        """
+            Four messages, without any prefix, no gsmtap header
+        """
+        msgs_input = [
+            "02 04 01 00 00 00 c9 00 00 1d 3c e5 02 00 01 00 15 06 21 00 01 f0 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b",
+            "02 04 01 00 00 00 ca 00 00 1d 3c e9 02 00 02 00 15 06 21 00 01 f0 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b",
+            "02 04 01 00 00 00 cb 00 00 1d 3d 0e 01 00 00 00 59 06 1a 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ff e5 04 00",
+            "02 04 01 00 00 00 cb 00 00 1d 3d 12 02 00 00 00 15 06 21 00 01 f0 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b"
+        ]
+        
+        # there is a whitespace at the beginning of message_printer output
+        msgs_expected = [
+            " 15 06 21 00 01 f0 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b",
+            " 15 06 21 00 01 f0 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b",
+            " 59 06 1a 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ff e5 04 00",
+            " 15 06 21 00 01 f0 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b"
+        ]
+        
+        src = grgsm.message_source(msgs_input)
+        printer = grgsm.message_printer(pmt.intern(""), False)
+        self.tb.msg_connect(src, "msgs", printer, "msgs")
+        self.tb.run()
+
+        self.assertEqual(self.getOutput(), self.getOutputExpected(msgs_expected))
+
+
+    def test_002_prefix_no_header (self):
+        """
+            Four messages, with prefix "test_002:", no gsmtap header
+        """
+        msgs_input = [
+            "02 04 01 00 00 00 c9 00 00 1d 3c e5 02 00 01 00 15 06 21 00 01 f0 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b",
+            "02 04 01 00 00 00 ca 00 00 1d 3c e9 02 00 02 00 15 06 21 00 01 f0 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b",
+            "02 04 01 00 00 00 cb 00 00 1d 3d 0e 01 00 00 00 59 06 1a 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ff e5 04 00",
+            "02 04 01 00 00 00 cb 00 00 1d 3d 12 02 00 00 00 15 06 21 00 01 f0 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b"
+        ]
+        
+        msgs_expected = [
+            "test_002: 15 06 21 00 01 f0 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b",
+            "test_002: 15 06 21 00 01 f0 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b",
+            "test_002: 59 06 1a 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ff e5 04 00",
+            "test_002: 15 06 21 00 01 f0 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b"
+        ]
+        
+        src = grgsm.message_source(msgs_input)
+        printer = grgsm.message_printer(pmt.intern("test_002:"), False)
+        self.tb.msg_connect(src, "msgs", printer, "msgs")
+        self.tb.run()
+
+        self.assertEqual(self.getOutput(), self.getOutputExpected(msgs_expected))
+
+
+    def test_003_no_prefix_header (self):
+        """
+            Four messages, without any prefix, with gsmtap header
+        """
+        msgs_input = [
+            "02 04 01 00 00 00 c9 00 00 1d 3c e5 02 00 01 00 15 06 21 00 01 f0 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b",
+            "02 04 01 00 00 00 ca 00 00 1d 3c e9 02 00 02 00 15 06 21 00 01 f0 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b",
+            "02 04 01 00 00 00 cb 00 00 1d 3d 0e 01 00 00 00 59 06 1a 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ff e5 04 00",
+            "02 04 01 00 00 00 cb 00 00 1d 3d 12 02 00 00 00 15 06 21 00 01 f0 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b"
+        ]
+        
+        # there is a whitespace at the beginning of message_printer output
+        msgs_expected = [
+            " 02 04 01 00 00 00 c9 00 00 1d 3c e5 02 00 01 00 15 06 21 00 01 f0 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b",
+            " 02 04 01 00 00 00 ca 00 00 1d 3c e9 02 00 02 00 15 06 21 00 01 f0 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b",
+            " 02 04 01 00 00 00 cb 00 00 1d 3d 0e 01 00 00 00 59 06 1a 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ff e5 04 00",
+            " 02 04 01 00 00 00 cb 00 00 1d 3d 12 02 00 00 00 15 06 21 00 01 f0 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b"
+        ]
+        
+        src = grgsm.message_source(msgs_input)
+        printer = grgsm.message_printer(pmt.intern(""), True)
+        self.tb.msg_connect(src, "msgs", printer, "msgs")
+        self.tb.run()
+
+        self.assertEqual(self.getOutput(), self.getOutputExpected(msgs_expected))
+        
+
+    def test_004_prefix_header (self):
+        """
+            Four messages, with prefix "test_004:", with gsmtap header
+        """
+        msgs_input = [
+            "02 04 01 00 00 00 c9 00 00 1d 3c e5 02 00 01 00 15 06 21 00 01 f0 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b",
+            "02 04 01 00 00 00 ca 00 00 1d 3c e9 02 00 02 00 15 06 21 00 01 f0 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b",
+            "02 04 01 00 00 00 cb 00 00 1d 3d 0e 01 00 00 00 59 06 1a 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ff e5 04 00",
+            "02 04 01 00 00 00 cb 00 00 1d 3d 12 02 00 00 00 15 06 21 00 01 f0 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b"
+        ]
+        
+        # there is a whitespace at the beginning of message_printer output
+        msgs_expected = [
+            "test_004: 02 04 01 00 00 00 c9 00 00 1d 3c e5 02 00 01 00 15 06 21 00 01 f0 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b",
+            "test_004: 02 04 01 00 00 00 ca 00 00 1d 3c e9 02 00 02 00 15 06 21 00 01 f0 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b",
+            "test_004: 02 04 01 00 00 00 cb 00 00 1d 3d 0e 01 00 00 00 59 06 1a 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ff e5 04 00",
+            "test_004: 02 04 01 00 00 00 cb 00 00 1d 3d 12 02 00 00 00 15 06 21 00 01 f0 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b"
+        ]
+        
+        src = grgsm.message_source(msgs_input)
+        printer = grgsm.message_printer(pmt.intern("test_004:"), True)
+        self.tb.msg_connect(src, "msgs", printer, "msgs")
+        self.tb.run()
+
+        self.assertEqual(self.getOutput(), self.getOutputExpected(msgs_expected))
+        
+        
+if __name__ == '__main__':
+    gr_unittest.run(qa_message_printer, "qa_message_printer.xml")
+