message_parser: add option to override messages

.pylintrc

@@ -1,5 +1,7 @@
 [FORMAT]
 max-line-length=180
+class-naming-style=PascalCase
+attr-naming-style=any
 
 [MASTER]
 ignore-paths=src/nasdaq_protocols/_version.py
@@ -12,4 +14,6 @@ disable=
     R0903, #too-few-public-methods
     R0902, #too-many-instance-attributes
     W0707, #too-many-statements
-    R0801, #similarities
+    R0801, #similarities
+    R0913, #too-many-arguments
+    R0917, #too-many-positional-arguments

src/nasdaq_protocols/common/message/parser.py

@@ -157,7 +157,7 @@ def get_codegen_context(self):
 
 class Parser:
     @staticmethod
-    def parse(file: str) -> Definitions:
+    def parse(file: str, override_messages: bool = False) -> Definitions:
         root = ElementTree.parse(file).getroot()
         elements = list(root)
         definitions = Definitions()
@@ -170,7 +170,7 @@ def parse(file: str) -> Definitions:
             elif element.tag == 'records-root':
                 definitions.records = {_.name: _ for _ in Parser._parse_records(element)}
             elif element.tag == 'messages-root':
-                definitions.messages = Parser._parse_messages(element)
+                definitions.messages = Parser._parse_messages(element, override_messages)
 
         return definitions
 
@@ -183,14 +183,21 @@ def _parse_records(element) -> list[RecordDef]:
         return [RecordDef(record.get('id'), Parser._parse_fields(record[0])) for record in list(element)]
 
     @staticmethod
-    def _parse_messages(element) -> list[MessageDef]:
+    def _parse_messages(element, override_messages: bool = False) -> list[MessageDef]:
         def create_msg(child):
             return MessageDef(
                 child.get('id'), child.get('message-id'), child.get('message-group'),
                 Parser._parse_fields(child[0] if len(child) else None),
                 child.get('direction')
             )
-        return [create_msg(child) for child in list(element) if child is not None]
+        messages = {}
+        for child in list(element):
+            msg = create_msg(child)
+            key = f'{msg.id}-{msg.group}-{msg.direction}'
+            if key in messages and not override_messages:
+                raise ValueError(f'Message {key} already exists')
+            messages[key] = msg
+        return list(messages.values())
 
     @staticmethod
     def _parse_fields(element) -> list[FieldDef]:

src/nasdaq_protocols/itch/codegen.py

@@ -12,13 +12,14 @@
 @click.option('--app-name', type=click.STRING)
 @click.option('--prefix', type=click.STRING, default='')
 @click.option('--op-dir', type=click.Path(exists=True, writable=True))
+@click.option('--override-messages/--no-override-messages', show_default=True, default=True)
 @click.option('--init-file/--no-init-file', show_default=True, default=True)
-def generate(spec_file, app_name, prefix, op_dir, init_file):
+def generate(spec_file, app_name, prefix, op_dir, override_messages, init_file):
     context = {
         'record_type': 'Record',
     }
     generator = Generator(
-        Parser.parse(spec_file),
+        Parser.parse(spec_file, override_messages=override_messages),
         'itch',
         app_name,
         op_dir,

src/nasdaq_protocols/ouch/codegen.py

@@ -12,13 +12,14 @@
 @click.option('--app-name', type=click.STRING)
 @click.option('--prefix', type=click.STRING, default='')
 @click.option('--op-dir', type=click.Path(exists=True, writable=True))
+@click.option('--override-messages/--no-override-messages', show_default=True, default=True)
 @click.option('--init-file/--no-init-file', show_default=True, default=True)
-def generate(spec_file, app_name, op_dir, prefix, init_file):
+def generate(spec_file, app_name, op_dir, prefix, override_messages, init_file):
     context = {
         'record_type': 'Record',
     }
     generator = Generator(
-        Parser.parse(spec_file),
+        Parser.parse(spec_file, override_messages=override_messages),
         'ouch',
         app_name,
         op_dir,

tests/test_common_message_parser.py

@@ -1,3 +1,5 @@
+import pytest
+
 from nasdaq_protocols.common.message import parser
 from .testdata import *
 
@@ -176,3 +178,19 @@ def test__parser__messages__codegen_context(tmp_file_writer):
             }
         ],
     }
+
+
+def test__parser__repeats_messages__no_overriding__parse(tmp_file_writer):
+    with pytest.raises(ValueError):
+        definitions = parser.Parser.parse(tmp_file_writer(TEST_XML_MESSAGES_REPEAT), override_messages=False)
+
+
+def test__parser__repeats_messages__overriding__parse(tmp_file_writer):
+
+    definitions = parser.Parser.parse(tmp_file_writer(TEST_XML_MESSAGES_REPEAT), override_messages=True)
+
+    assert len(definitions.messages) == 1
+    assert 'test_message_extn' in [msg.name for msg in definitions.messages]
+
+    message: parser.MessageDef = definitions.messages[0]
+    assert len(message.fields) == 2

tests/testdata.py

@@ -163,4 +163,29 @@
         </message>
     </messages-root>
 </root>
+"""
+
+
+TEST_XML_MESSAGES_REPEAT = """
+<root>
+    <enums-root>
+    </enums-root>
+    <fielddef-root>
+    </fielddef-root>
+    <records-root>
+    </records-root>
+    <messages-root>
+        <message id="test_message" message-id="1" message-group="2" direction="incoming">
+            <fields>
+                <field name="msg_field1" type="uint_4" default="0"/>
+            </fields>
+        </message>
+        <message id="test_message_extn" message-id="1" message-group="2" direction="incoming">
+            <fields>
+                <field name="msg_field1" type="uint_4" default="0"/>
+                <field name="msg_field2" type="uint_4" default="0"/>
+            </fields>
+        </message>
+    </messages-root>
+</root>
 """