Update CHANGELOG, enhance configuration loading with default values, and add tests for missing defaults

CHANGELOG.md

@@ -4,11 +4,11 @@
 
 ## Version 2.0.0 - Comprehensive Code Review and Enhancements (December 31, 2025)
 
-### 🐛 Bug Fixes
+### Bug Fixes
 - **Fixed test file errors**: Corrected incomplete string in `test_config_handler.py` and wrong function name in `test_protocol.py`
 - **Fixed missing method**: Added `_on_log` method to `MQTTHandler` that was referenced but not defined
 
-### ✨ New Features
+### New Features
 
 #### 1. Metrics and Statistics Collection
 - **New Module**: `ammb/metrics.py`
@@ -70,7 +70,7 @@
   - Configurable insecure mode (for testing)
   - Automatic TLS context creation
 
-### 🔧 Enhancements
+### Enhancements
 
 #### Configuration System
 - Added API configuration options:
@@ -111,32 +111,32 @@
 - Enhanced shutdown sequence
 - Better error handling and logging
 
-### 📊 Performance Optimizations
+### Performance Optimizations
 - Thread-safe metrics collection
 - Non-blocking message logging
 - Efficient rate limiting algorithm
 - Optimized health check intervals
 - Reduced lock contention
 
-### 🛡️ Security Enhancements
+### Security Enhancements
 - Message validation prevents malformed data
 - Rate limiting prevents message flooding
 - TLS/SSL support for secure MQTT
 - Input sanitization prevents injection attacks
 - Node ID validation prevents spoofing
 
-### 📝 Documentation
+### Documentation
 - Updated README.md with new features
 - Enhanced configuration examples
 - Added API endpoint documentation
 - Improved code comments and docstrings
 
-### 🧪 Testing
+### Testing
 - Fixed broken test files
 - All modules compile successfully
 - No linter errors
 
-### 🔄 Backward Compatibility
+### Backward Compatibility
 - All new features are optional and configurable
 - Default behavior maintains backward compatibility
 - Existing configurations continue to work

ammb/config_handler.py

@@ -100,14 +100,12 @@ def load_config(config_path: str = CONFIG_FILE) -> Optional[BridgeConfig]:
 
         if 'DEFAULT' not in config.sections():
              logger.warning(f"Configuration file '{config_path}' lacks the [DEFAULT] section. Using only defaults.")
-             cfg_section = config.defaults()
-        else:
-             cfg_section = config['DEFAULT']
+        cfg_section = config['DEFAULT']
 
-        meshtastic_port = cfg_section.get('MESHTASTIC_SERIAL_PORT')
-        external_network_id = cfg_section.get('EXTERNAL_NETWORK_ID')
-        bridge_node_id = cfg_section.get('BRIDGE_NODE_ID')
-        log_level = cfg_section.get('LOG_LEVEL').upper()
+        meshtastic_port = cfg_section.get('MESHTASTIC_SERIAL_PORT', fallback=DEFAULT_CONFIG['MESHTASTIC_SERIAL_PORT'])
+        external_network_id = cfg_section.get('EXTERNAL_NETWORK_ID', fallback=DEFAULT_CONFIG['EXTERNAL_NETWORK_ID'])
+        bridge_node_id = cfg_section.get('BRIDGE_NODE_ID', fallback=DEFAULT_CONFIG['BRIDGE_NODE_ID'])
+        log_level = cfg_section.get('LOG_LEVEL', fallback=DEFAULT_CONFIG['LOG_LEVEL']).upper()
         
         if log_level not in VALID_LOG_LEVELS:
             logger.error(f"Invalid LOG_LEVEL '{log_level}'. Must be one of: {VALID_LOG_LEVELS}")
@@ -121,7 +119,7 @@ def load_config(config_path: str = CONFIG_FILE) -> Optional[BridgeConfig]:
             logger.error(f"Invalid integer value for MESSAGE_QUEUE_SIZE: {e}")
             return None
 
-        external_transport = cfg_section.get('EXTERNAL_TRANSPORT').lower()
+        external_transport = cfg_section.get('EXTERNAL_TRANSPORT', fallback=DEFAULT_CONFIG['EXTERNAL_TRANSPORT']).lower()
         if external_transport not in VALID_TRANSPORTS:
             logger.error(f"Invalid EXTERNAL_TRANSPORT '{external_transport}'. Must be one of: {VALID_TRANSPORTS}")
             return None
@@ -140,8 +138,8 @@ def load_config(config_path: str = CONFIG_FILE) -> Optional[BridgeConfig]:
         mqtt_retain_out = None
 
         if external_transport == 'serial':
-            serial_port = cfg_section.get('SERIAL_PORT')
-            serial_protocol = cfg_section.get('SERIAL_PROTOCOL').lower()
+            serial_port = cfg_section.get('SERIAL_PORT', fallback=DEFAULT_CONFIG['SERIAL_PORT'])
+            serial_protocol = cfg_section.get('SERIAL_PROTOCOL', fallback=DEFAULT_CONFIG['SERIAL_PROTOCOL']).lower()
             if not serial_port:
                  logger.error("SERIAL_PORT must be set when EXTERNAL_TRANSPORT is 'serial'.")
                  return None

tests/test_config_handler_missing_default.py

@@ -0,0 +1,14 @@
+import importlib.util
+
+
+def test_load_config_missing_default(tmp_path):
+    cfgfile = tmp_path / "no_default.ini"
+    cfgfile.write_text("[serial]\nSERIAL_PORT=/dev/ttyS1\n")
+
+    spec = importlib.util.spec_from_file_location('config_handler', 'ammb/config_handler.py')
+    mod = importlib.util.module_from_spec(spec)
+    spec.loader.exec_module(mod)
+
+    cfg = mod.load_config(str(cfgfile))
+    assert cfg is not None
+    assert cfg.log_level == 'INFO'

tmp_no_default.ini

@@ -0,0 +1,2 @@
+[serial]
+SERIAL_PORT = /dev/ttyS1

tmp_run_load.py

@@ -0,0 +1,6 @@
+import importlib.util
+spec = importlib.util.spec_from_file_location('config_handler', 'ammb/config_handler.py')
+mod = importlib.util.module_from_spec(spec)
+spec.loader.exec_module(mod)
+print('Using file: tmp_no_default.ini')
+print(mod.load_config('tmp_no_default.ini'))

tmp_test_config.py

@@ -0,0 +1,7 @@
+from ammb import config_handler
+path='tmp_no_default.ini'
+with open(path,'w') as f:
+    f.write('[serial]\nSERIAL_PORT=/dev/ttyS1\n')
+print('Using file:', path)
+cfg = config_handler.load_config(path)
+print('Result:', cfg)