fix: correct return value order in Java test_runner for coverage

codeflash/languages/java/test_runner.py

@@ -309,8 +309,33 @@ def run_behavioral_tests(
     surefire_dir = target_dir / "surefire-reports"
     result_xml_path = _get_combined_junit_xml(surefire_dir, candidate_index)
 
-    # Return coverage_xml_path as the fourth element when coverage is enabled
-    return result_xml_path, result, sqlite_db_path, coverage_xml_path
+    # Debug: Log Maven result and coverage file status
+    if enable_coverage:
+        logger.info(f"Maven verify completed with return code: {result.returncode}")
+        if result.returncode != 0:
+            logger.warning(f"Maven verify had non-zero return code: {result.returncode}. Coverage data may be incomplete.")
+
+    # Log coverage file status after Maven verify
+    if enable_coverage and coverage_xml_path:
+        jacoco_exec_path = target_dir / "jacoco.exec"
+        logger.info(f"Coverage paths - target_dir: {target_dir}, coverage_xml_path: {coverage_xml_path}")
+        if jacoco_exec_path.exists():
+            logger.info(f"JaCoCo exec file exists: {jacoco_exec_path} ({jacoco_exec_path.stat().st_size} bytes)")
+        else:
+            logger.warning(f"JaCoCo exec file not found: {jacoco_exec_path} - JaCoCo agent may not have run")
+        if coverage_xml_path.exists():
+            file_size = coverage_xml_path.stat().st_size
+            logger.info(f"JaCoCo XML report exists: {coverage_xml_path} ({file_size} bytes)")
+            if file_size == 0:
+                logger.warning(f"JaCoCo XML report is empty - report generation may have failed")
+        else:
+            logger.warning(f"JaCoCo XML report not found: {coverage_xml_path} - verify phase may not have completed")
+
+    # Return tuple matching the expected signature:
+    # (result_xml_path, run_result, coverage_database_file, coverage_config_file)
+    # For Java: coverage_database_file is the jacoco.xml path, coverage_config_file is not used (None)
+    # The sqlite_db_path is used internally for behavior capture but doesn't need to be returned
+    return result_xml_path, result, coverage_xml_path, None
 
 
 def _compile_tests(

codeflash/verification/coverage_utils.py

@@ -206,14 +206,32 @@ def load_from_jacoco_xml(
 
         """
         if not jacoco_xml_path or not jacoco_xml_path.exists():
-            logger.debug(f"JaCoCo XML file not found: {jacoco_xml_path}")
+            logger.warning(f"JaCoCo XML file not found at path: {jacoco_xml_path}")
+            return CoverageData.create_empty(source_code_path, function_name, code_context)
+
+        # Log file info for debugging
+        file_size = jacoco_xml_path.stat().st_size
+        logger.info(f"Parsing JaCoCo XML file: {jacoco_xml_path} (size: {file_size} bytes)")
+
+        if file_size == 0:
+            logger.warning(f"JaCoCo XML file is empty: {jacoco_xml_path}")
             return CoverageData.create_empty(source_code_path, function_name, code_context)
 
         try:
             tree = ET.parse(jacoco_xml_path)
             root = tree.getroot()
         except ET.ParseError as e:
-            logger.warning(f"Failed to parse JaCoCo XML file: {e}")
+            # Log detailed debugging info
+            try:
+                with jacoco_xml_path.open(encoding="utf-8") as f:
+                    content_preview = f.read(500)
+                logger.warning(
+                    f"Failed to parse JaCoCo XML file at '{jacoco_xml_path}' "
+                    f"(size: {file_size} bytes, exists: {jacoco_xml_path.exists()}): {e}. "
+                    f"File preview: {content_preview!r}"
+                )
+            except Exception as read_err:
+                logger.warning(f"Failed to parse JaCoCo XML file at '{jacoco_xml_path}': {e}. Could not read file: {read_err}")
             return CoverageData.create_empty(source_code_path, function_name, code_context)
 
         # Determine expected source file name from path