Support byte values when converting field to iso8583 - DE55 (issue #15)

cardutil/iso8583.py

@@ -265,16 +265,22 @@ def _dict_to_iso8583(message, bit_config, encoding=DEFAULT_ENCODING, hex_bitmap=
 
 def _field_to_iso8583(bit_config, field_value, encoding=DEFAULT_ENCODING):
 
-    output = ''
+    output = b''
     LOGGER.debug(f'bit_config={bit_config}, field_value={field_value}, encoding={encoding}')
     field_value = _pytype_to_string(field_value, bit_config)
     field_length = bit_config.get('field_length')
     length_size = _get_field_length(bit_config)  # size of length for llvar and lllvar fields
+
     if length_size > 0:
         field_length = len(field_value)
-        output += format(field_length, '0' + str(length_size))
-    output += format(field_value[:field_length], '<' + str(field_length))
-    return output.encode(encoding)
+        output += format(field_length, '0' + str(length_size)).encode(encoding)
+
+    if isinstance(field_value, bytes):
+        output += field_value[:field_length]
+    else:
+        output += format(field_value[:field_length], '<' + str(field_length)).encode(encoding)
+
+    return output
 
 
 def _iso8583_to_field(bit, bit_config, message_data, encoding=DEFAULT_ENCODING):

docs/source/contributing.rst

@@ -68,6 +68,11 @@ unit test
 
     $ pytest
 
+If you want to run with debug messages displayed::
+
+    $ pytest --log-cli-level=10
+
+
 coverage
 --------
 

setup.cfg

@@ -1,3 +1,6 @@
+[pytest]
+log_cli = true
+
 [bumpversion]
 current_version = 0.6.3
 tag = True

tests/cli/test_mci_ipm_to_csv.py

@@ -87,6 +87,8 @@ def test_ipm_to_csv_generate_exception(self):
         """
         Actually run using real files, and exception generated
         Triggered through negative RDW on second record -- invalid record length
+        KNOWN ISSUE: when pytest run with logging, this test will fail.
+        TODO Fix so this test works with pytest debug on
         :return:
         """
         in_ipm_data = (b'\x00\x00\x00\x1a0100\x80\x00\x00\x00\x04\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00'

tests/test_iso8583.py

@@ -152,6 +152,18 @@ def test_field_to_iso8583(self):
                  'field_length': 12, "field_date_format": "%y%m%d%H%M%S"},
                 datetime.datetime(2014, 1, 2, 15, 16, 10)))
 
+    def test_field_to_iso8583_binary_field(self):
+        """
+        https://github.com/adelosa/cardutil/issues/15
+        Ensure function can support processing of byte values representing binary fields like DE55
+        """
+        bit_config = {
+            'field_name': 'binary field', 'field_type': 'LLLVAR', 'field_length': 255}
+        field_value = b'\x01\x01\x41\x9f\x01\x02\x12\x34'
+        encoding = 'latin_1'
+        field_output = _field_to_iso8583(bit_config, field_value, encoding)
+        self.assertEqual(b'008\x01\x01A\x9f\x01\x02\x124', field_output)
+
     def test_iso8583_to_dict(self):
         expected_dict = {'MTI': '1144', 'DE2': '4444555544445555', 'DE3': '111111', 'DE4': 9999,
                          'DE12': datetime.datetime(2015, 8, 15, 17, 15, 0),