Enhance handler function documentation and update coverage exclusions for preview environment

Author: neil-sproston

infrastructure/environments/preview/handler.py

@@ -6,12 +6,23 @@
 logger.setLevel(logging.INFO)
 
 
-def handler(event: dict[str, Any], context):
+def handler(event: dict[str, Any], context: Any):
+    """Handler for the preview environment. This simply returns a 200 response with
+       the request headers, which can be used to verify and debug how the environment 
+       is working and to inspect the incoming request.
+
+    Args:
+        event (dict[str, Any]): The event dictionary containing request data from API Gateway.
+        context (Any): AWS lambda context object (what the lambda is running in)
+
+    Returns:
+        dict: Diagnostic 200 response with request headers.
+    """
     logger.info("Lambda context: %s", context)
     headers = event.get("headers", {}) or {}
 
     # Log headers to CloudWatch
-    logger.info("Incoming request headers:")  # pragma: no cover
+    logger.info("Incoming request headers:")
     for k, v in headers.items():
         logger.info("%s: %s", k, v)
 

sonar-project.properties

@@ -13,6 +13,6 @@ sonar.exclusions=docs/**,pathology-api/test-artefacts/**,pathology-api/coverage-
 sonar.tests=pathology-api
 sonar.test.inclusions=pathology-api/**/test_*.py, pathology-api/tests/**
 
-sonar.coverage.exclusions=**/tests/**,**/features/**,**/test_*.py,infrastructure/images/api-gateway-mock/resources/**
+sonar.coverage.exclusions=**/tests/**,**/features/**,**/test_*.py,infrastructure/images/api-gateway-mock/resources/**,**/infrastructure/environments/preview/**
 # Set Python version for more precise analysis
 sonar.python.version=3.14