Replace structured-classes with Python struct module for serialization

.github/workflows/test.yml

@@ -36,7 +36,7 @@ jobs:
     - name: Install Python dependencies
       run: |
         python -m pip install --upgrade pip
-        pip install proto-schema-parser structured-classes
+        pip install proto-schema-parser
 
     - name: Install Node.js dependencies
       run: npm ci

.gitignore

@@ -35,3 +35,4 @@ Thumbs.db
 *.swp
 *.swo
 *~
+*.bak

pyproject.toml

@@ -9,7 +9,6 @@ authors = [
   { name="Rijesh Augustine", email="rijesh@mylonics.com" },
 ]
 dependencies = [
-    "structured-classes>=3.1.0",
     "proto-schema-parser>=1.4.5",
 ]
 description = "A framework for serializing data with headers"

src/struct_frame/boilerplate/py/struct_frame_parser.py

@@ -64,7 +64,9 @@ def encode(self, data, msg_id):
         if (len(data)):
             for b in data:
                 output.append(b)
-        checksum = fletcher_checksum_calculation(data)
+        # Calculate checksum on msg_id + data (consistent with validate_packet)
+        checksum_data = [msg_id] + list(data)
+        checksum = fletcher_checksum_calculation(checksum_data)
 
         output.append(checksum[0])
         output.append(checksum[1])

tests/cross_platform_test.py

@@ -266,17 +266,13 @@ def test_cross_platform(self, encoder_lang: str, decoder_lang: str, framed: bool
 
     def check_language_available(self, language: str, mode: str = "framed") -> bool:
         """Check if encoder/decoder for a language are available"""
-        # NOTE: Python and TypeScript are currently disabled due to known limitations:
-        # - Python: The structured-classes library's pack() method doesn't properly
-        #   serialize variable-length strings and arrays. Only fixed-size primitive
-        #   fields are included in the packed output, preventing proper cross-platform
-        #   message encoding.
+        # NOTE: TypeScript is currently disabled due to known limitations:
         # - TypeScript: Generated code has a runtime error where the .Array() method
         #   doesn't exist on the typed-struct builder object. This is a code generation
         #   bug in struct-frame's TypeScript generator.
         #
         # Once these issues are resolved, remove the early return below.
-        if language in ["python", "typescript"]:
+        if language in ["typescript"]:
             return False
 
         if language == "c":
@@ -327,8 +323,8 @@ def run_all_tests(self, test_struct=True, test_framed=True):
             print("="*60)
             self.log("Struct-based tests are currently NOT IMPLEMENTED", "WARNING")
             self.log(
-                "This is due to limitations in variable-length field serialization", "WARNING")
-            self.log("in the Python structured-classes library.", "WARNING")
+                "This is due to encoder/decoder implementations not being complete", "WARNING")
+            self.log("for all languages in struct mode.", "WARNING")
             self.log("TEST FAILED: Struct-based tests not implemented", "ERROR")
 
         # Test framed mode

tests/py/encoder_framed.py

@@ -11,24 +11,17 @@
 sys.path.insert(0, os.path.join(os.path.dirname(__file__), '../generated/py'))
 
 try:
-    from serialization_test_sf import SerializationTestSerializationTestMessage, _VariableString_test_string, _BoundedArray_test_array
+    from serialization_test_sf import SerializationTestSerializationTestMessage
     from struct_frame_parser import BasicPacket
 
-    # Create variable string for test_string (matching the test_serialization.py format)
-    test_string = _VariableString_test_string(
-        18, b"Hello from Python!")  # length=18, data
-
-    # Create bounded array for test_array (matching the test_serialization.py format)
-    test_array = _BoundedArray_test_array(
-        3, [100, 200, 300, 0, 0])  # 3 elements in use, max 5
-
     # Create test message with known values
+    # The new struct-based generator uses direct values instead of wrapper classes
     msg = SerializationTestSerializationTestMessage(
-        0xDEADBEEF,  # magic_number
-        test_string,  # test_string
-        3.14159,     # test_float
-        True,        # test_bool
-        test_array   # test_array
+        magic_number=0xDEADBEEF,
+        test_string=b"Hello from Python!",
+        test_float=3.14159,
+        test_bool=True,
+        test_array=[100, 200, 300]
     )
 
     # Serialize with framing using BasicPacket

tests/py/encoder_struct.py

@@ -14,16 +14,15 @@
     from serialization_test_sf import SerializationTestSerializationTestMessage
 
     # Create test message with known values
+    # The new struct-based generator uses bytes for strings
     msg = SerializationTestSerializationTestMessage(
-        0xDEADBEEF,  # magic_number
-        3.14159,     # test_float
-        True         # test_bool
+        magic_number=0xDEADBEEF,
+        test_string=b"Hello from Python!",
+        test_float=3.14159,
+        test_bool=True,
+        test_array=[100, 200, 300]
     )
 
-    # Set string and array fields
-    msg.test_string = "Hello from Python!"
-    msg.test_array = [100, 200, 300]
-
     # Serialize to struct bytes (no framing) using pack()
     struct_bytes = msg.pack()
 

tests/py/test_serialization.py

@@ -34,18 +34,17 @@ def create_test_data():
     """Create test data for cross-language compatibility testing"""
     try:
         sys.path.insert(0, '../generated/py')
-        from serialization_test_sf import (
-            SerializationTestSerializationTestMessage, 
-            _BoundedArray_test_array,
-            _VariableString_test_string
-        )
+        from serialization_test_sf import SerializationTestSerializationTestMessage
         from struct_frame_parser import BasicPacket
 
-        test_string = _VariableString_test_string(18, b"Hello from Python!")
-        test_array = _BoundedArray_test_array(3, [100, 200, 300, 0, 0])
-
+        # Create test message with known values
+        # The new struct-based generator uses direct values instead of wrapper classes
         msg = SerializationTestSerializationTestMessage(
-            0xDEADBEEF, test_string, 3.14159, True, test_array
+            magic_number=0xDEADBEEF,
+            test_string=b"Hello from Python!",
+            test_float=3.14159,
+            test_bool=True,
+            test_array=[100, 200, 300]
         )
 
         packet = BasicPacket()