feat: Java testgen class name fix, remove per-test @timeout, and wire language_version

- Add class_name and qualified_name to /testgen API payload so the backend
  has explicit access to computed FunctionToOptimize properties
- Add client-side _fix_java_test_class_name() to correct wrong class name
  references in LLM-generated Java test code
- Remove per-test @timeout annotation from Java instrumentation (causes
  timing instability on CI runners; Maven Surefire handles timeouts)
- Remove redundant default_language_version, use language_version as canonical

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: Ubuntu

.claude/rules/architecture.md

@@ -64,7 +64,7 @@ Core protocol in `languages/base.py`. Each language (`PythonSupport`, `JavaScrip
 |----------|----------------|---------|
 | Identity | `language`, `file_extensions`, `default_file_extension` | Language identification |
 | Identity | `comment_prefix`, `dir_excludes` | Language conventions |
-| AI service | `default_language_version` | Language version for API payloads (`None` for Python, `"ES2022"` for JS) |
+| AI service | `language_version` | Detected language version for API payloads (e.g., `"3.11.0"` for Python, `"17"` for Java) |
 | AI service | `valid_test_frameworks` | Allowed test frameworks for validation |
 | Discovery | `discover_functions`, `discover_tests` | Find optimizable functions and their tests |
 | Discovery | `adjust_test_config_for_discovery` | Pre-discovery config adjustment (no-op default) |

codeflash/api/aiservice.py

@@ -129,8 +129,7 @@ def optimize_code(
         experiment_metadata: ExperimentMetadata | None = None,
         *,
         language: str = "python",
-        language_version: str
-        | None = None,  # TODO:{claude} add language version to the language support and it should be cached
+        language_version: str | None = None,
         module_system: str | None = None,
         is_async: bool = False,
         n_candidates: int = 5,
@@ -177,16 +176,12 @@ def optimize_code(
             "is_numerical_code": is_numerical_code,
         }
 
-        # Add language-specific version fields
-        # Always include python_version for backward compatibility with older backend
-        payload["python_version"] = platform.python_version()
-        if is_python():
-            pass  # python_version already set
-        elif is_java():
-            payload["language_version"] = language_version or "17"  # Default Java version
-        else:
-            payload["language_version"] = language_version or "ES2022"
-            # Add module system for JavaScript/TypeScript (esm or commonjs)
+        # Add language version (canonical for all languages)
+        payload["language_version"] = language_version
+        # Backward compat: backend still expects python_version
+        payload["python_version"] = language_version if is_python() else platform.python_version()
+
+        if not is_python():
             if module_system:
                 payload["module_system"] = module_system
 
@@ -262,7 +257,8 @@ def get_jit_rewritten_code(self, source_code: str, trace_id: str) -> list[Optimi
             "source_code": source_code,
             "trace_id": trace_id,
             "dependency_code": "",  # dummy value to please the api endpoint
-            "python_version": "3.12.1",  # dummy value to please the api endpoint
+            "language_version": platform.python_version(),
+            "python_version": platform.python_version(),  # backward compat
             "current_username": get_last_commit_author_if_pr_exists(None),
             "repo_owner": git_repo_owner,
             "repo_name": git_repo_name,
@@ -329,18 +325,15 @@ def optimize_python_code_line_profiler(
         logger.info("Generating optimized candidates with line profiler…")
         console.rule()
 
-        # Set python_version for backward compatibility with Python, or use language_version
-        python_version = language_version if language_version else platform.python_version()
-
         payload = {
             "source_code": source_code,
             "dependency_code": dependency_code,
             "n_candidates": n_candidates,
             "line_profiler_results": line_profiler_results,
             "trace_id": trace_id,
-            "python_version": python_version,
             "language": language,
             "language_version": language_version,
+            "python_version": language_version if is_python() else platform.python_version(),  # backward compat
             "experiment_metadata": experiment_metadata,
             "codeflash_version": codeflash_version,
             "call_sequence": self.get_next_sequence(),
@@ -434,14 +427,10 @@ def optimize_code_refinement(self, request: list[AIServiceRefinerRequest]) -> li
                 "language": opt.language,
             }
 
-            # Add language version - always include python_version for backward compatibility
-            item["python_version"] = platform.python_version()
-            if is_python():
-                pass  # python_version already set
-            elif opt.language_version:
-                item["language_version"] = opt.language_version
-            else:
-                item["language_version"] = "ES2022"  # Default for JS/TS
+            # Add language version (canonical for all languages)
+            item["language_version"] = opt.language_version
+            # Backward compat: backend still expects python_version
+            item["python_version"] = opt.language_version if is_python() else platform.python_version()
 
             # Add multi-file context if provided
             if opt.additional_context_files:
@@ -649,7 +638,8 @@ def generate_ranking(
             "diffs": diffs,
             "speedups": speedups,
             "optimization_ids": optimization_ids,
-            "python_version": platform.python_version(),
+            "language_version": platform.python_version(),
+            "python_version": platform.python_version(),  # backward compat
             "function_references": function_references,
         }
         logger.info("loading|Generating ranking")
@@ -785,18 +775,16 @@ def generate_regression_tests(
             "is_async": function_to_optimize.is_async,
             "call_sequence": self.get_next_sequence(),
             "is_numerical_code": is_numerical_code,
+            "class_name": function_to_optimize.class_name,
+            "qualified_name": function_to_optimize.qualified_name,
         }
 
-        # Add language-specific version fields
-        # Always include python_version for backward compatibility with older backend
-        payload["python_version"] = platform.python_version()
-        if is_python():
-            pass  # python_version already set
-        elif is_java():
-            payload["language_version"] = language_version or "17"  # Default Java version
-        else:
-            payload["language_version"] = language_version or "ES2022"
-            # Add module system for JavaScript/TypeScript (esm or commonjs)
+        # Add language version (canonical for all languages)
+        payload["language_version"] = language_version
+        # Backward compat: backend still expects python_version
+        payload["python_version"] = language_version if is_python() else platform.python_version()
+
+        if not is_python():
             if module_system:
                 payload["module_system"] = module_system
 
@@ -884,7 +872,8 @@ def get_optimization_review(
             "codeflash_version": codeflash_version,
             "calling_fn_details": calling_fn_details,
             "language": language,
-            "python_version": platform.python_version() if is_python() else None,
+            "language_version": platform.python_version() if is_python() else None,
+            "python_version": platform.python_version() if is_python() else None,  # backward compat
             "call_sequence": self.get_next_sequence(),
         }
         console.rule()

codeflash/api/schemas.py

@@ -137,14 +137,15 @@ def to_payload(self) -> dict[str, Any]:
             "is_numerical_code": self.is_numerical_code,
         }
 
-        # Add language-specific fields
-        if self.language_info.version:
-            payload["language_version"] = self.language_info.version
+        # Add language version (canonical for all languages)
+        payload["language_version"] = self.language_info.version
 
-        # Backward compat: always include python_version
+        # Backward compat: backend still expects python_version
         import platform
 
-        payload["python_version"] = platform.python_version()
+        payload["python_version"] = (
+            self.language_info.version if self.language_info.name == "python" else platform.python_version()
+        )
 
         # Module system for JS/TS
         if self.language_info.module_system != ModuleSystem.UNKNOWN:
@@ -205,14 +206,15 @@ def to_payload(self) -> dict[str, Any]:
             "is_numerical_code": self.is_numerical_code,
         }
 
-        # Add language version
-        if self.language_info.version:
-            payload["language_version"] = self.language_info.version
+        # Add language version (canonical for all languages)
+        payload["language_version"] = self.language_info.version
 
-        # Backward compat: always include python_version
+        # Backward compat: backend still expects python_version
         import platform
 
-        payload["python_version"] = platform.python_version()
+        payload["python_version"] = (
+            self.language_info.version if self.language_info.name == "python" else platform.python_version()
+        )
 
         # Module system for JS/TS
         if self.language_info.module_system != ModuleSystem.UNKNOWN:

codeflash/languages/base.py

@@ -325,13 +325,9 @@ def dir_excludes(self) -> frozenset[str]:
         ...
 
     @property
-    def default_language_version(self) -> str | None:
-        """Default language version string sent to AI service.
-
-        Returns None for languages where the runtime version is auto-detected (e.g. Python).
-        Returns a version string (e.g. "ES2022") for languages that need an explicit default.
-        """
-        return None
+    def language_version(self) -> str | None:
+        """The detected language version (e.g., "17" for Java, "ES2022" for JS)."""
+        ...
 
     @property
     def valid_test_frameworks(self) -> tuple[str, ...]:

codeflash/languages/java/instrumentation.py

@@ -258,6 +258,7 @@ def wrap_target_calls_with_treesitter(
     precise_call_timing: bool = False,
     class_name: str = "",
     test_method_name: str = "",
+    target_return_type: str = "",
 ) -> tuple[list[str], int]:
     """Replace target method calls in body_lines with capture + serialize using tree-sitter.
 
@@ -327,6 +328,8 @@ def wrap_target_calls_with_treesitter(
             call_counter += 1
             var_name = f"_cf_result{iter_id}_{call_counter}"
             cast_type = _infer_array_cast_type(body_line)
+            if not cast_type and target_return_type and target_return_type != "void":
+                cast_type = target_return_type
             var_with_cast = f"({cast_type}){var_name}" if cast_type else var_name
 
             # Use per-call unique variables (with call_counter suffix) for behavior mode
@@ -524,6 +527,26 @@ def _infer_array_cast_type(line: str) -> str | None:
     return None
 
 
+def _extract_return_type(function_to_optimize: Any) -> str:
+    """Extract the return type of a Java function from its source file using tree-sitter."""
+    file_path = getattr(function_to_optimize, "file_path", None)
+    func_name = _get_function_name(function_to_optimize)
+    if not file_path or not file_path.exists():
+        return ""
+    try:
+        from codeflash.languages.java.parser import get_java_analyzer
+
+        analyzer = get_java_analyzer()
+        source_text = file_path.read_text(encoding="utf-8")
+        methods = analyzer.find_methods(source_text)
+        for method in methods:
+            if method.name == func_name and method.return_type:
+                return method.return_type
+    except Exception:
+        logger.debug("Could not extract return type for %s", func_name)
+    return ""
+
+
 def _get_qualified_name(func: Any) -> str:
     """Get the qualified name from FunctionToOptimize."""
     if hasattr(func, "qualified_name"):
@@ -617,6 +640,7 @@ def instrument_existing_test(
     """
     source = test_string
     func_name = _get_function_name(function_to_optimize)
+    target_return_type = _extract_return_type(function_to_optimize)
 
     # Get the original class name from the file name
     if test_path:
@@ -648,14 +672,16 @@ def instrument_existing_test(
         )
     else:
         # Behavior mode: add timing instrumentation that also writes to SQLite
-        modified_source = _add_behavior_instrumentation(modified_source, original_class_name, func_name)
+        modified_source = _add_behavior_instrumentation(
+            modified_source, original_class_name, func_name, target_return_type
+        )
 
     logger.debug("Java %s testing for %s: renamed class %s -> %s", mode, func_name, original_class_name, new_class_name)
     # Why return True here?
     return True, modified_source
 
 
-def _add_behavior_instrumentation(source: str, class_name: str, func_name: str) -> str:
+def _add_behavior_instrumentation(source: str, class_name: str, func_name: str, target_return_type: str = "") -> str:
     """Add behavior instrumentation to test methods.
 
     For behavior mode, this adds:
@@ -796,6 +822,7 @@ def _add_behavior_instrumentation(source: str, class_name: str, func_name: str)
                 precise_call_timing=True,
                 class_name=class_name,
                 test_method_name=test_method_name,
+                target_return_type=target_return_type,
             )
 
             # Add behavior instrumentation setup code (shared variables for all calls in the method)

codeflash/languages/java/support.py

@@ -64,6 +64,7 @@ def __init__(self) -> None:
         self._analyzer = get_java_analyzer()
         self.line_profiler_agent_arg: str | None = None
         self.line_profiler_warmup_iterations: int = 0
+        self._language_version: str | None = None
 
     @property
     def language(self) -> Language:
@@ -93,6 +94,10 @@ def default_file_extension(self) -> str:
     def dir_excludes(self) -> frozenset[str]:
         return frozenset({"target", "build", ".gradle", ".mvn", ".idea", "apidocs", "javadoc"})
 
+    @property
+    def language_version(self) -> str | None:
+        return self._language_version
+
     def postprocess_generated_tests(
         self, generated_tests: GeneratedTestsList, test_framework: str, project_root: Path, source_file_path: Path
     ) -> GeneratedTestsList:
@@ -364,10 +369,36 @@ def ensure_runtime_environment(self, project_root: Path) -> bool:
         if config is None:
             return False
 
+        self._language_version = config.java_version
+        if self._language_version is None:
+            self._detect_java_version()
+
         # For now, assume the runtime is available
         # A full implementation would check/install the JAR
         return True
 
+    def _detect_java_version(self) -> None:
+        """Detect and cache the Java runtime version."""
+        import subprocess
+
+        try:
+            result = subprocess.run(["java", "-version"], check=False, capture_output=True, text=True, timeout=10)
+            # java -version outputs to stderr, e.g. 'openjdk version "17.0.2"'
+            output = result.stderr or result.stdout
+            for line in output.splitlines():
+                if "version" in line:
+                    # Extract version between quotes: "17.0.2" -> "17"
+                    start = line.find('"')
+                    end = line.find('"', start + 1)
+                    if start != -1 and end != -1:
+                        full_version = line[start + 1 : end]
+                        # Use major version only: "17.0.2" -> "17", "1.8.0_292" -> "8"
+                        major = full_version.split(".")[0]
+                        self._language_version = "8" if major == "1" else major
+                        return
+        except Exception:
+            pass
+
     def instrument_existing_test(
         self,
         test_string: str,

codeflash/languages/javascript/support.py

@@ -36,6 +36,9 @@ class JavaScriptSupport:
     using tree-sitter for code analysis and Jest for test execution.
     """
 
+    def __init__(self) -> None:
+        self._language_version: str | None = None
+
     # === Properties ===
 
     @property
@@ -68,6 +71,10 @@ def comment_prefix(self) -> str:
     def dir_excludes(self) -> frozenset[str]:
         return frozenset({"node_modules", "dist", "build", ".next", ".nuxt", "coverage", ".cache", ".turbo", ".vercel"})
 
+    @property
+    def language_version(self) -> str | None:
+        return self._language_version
+
     # === Discovery ===
 
     def discover_functions(
@@ -2077,6 +2084,15 @@ def verify_requirements(self, project_root: Path, test_framework: str = "jest")
 
         return len(errors) == 0, errors
 
+    def _detect_node_version(self) -> None:
+        """Detect and cache the Node.js runtime version."""
+        try:
+            result = subprocess.run(["node", "--version"], check=False, capture_output=True, text=True, timeout=10)
+            if result.returncode == 0 and result.stdout.strip():
+                self._language_version = result.stdout.strip().lstrip("v")
+        except Exception:
+            pass
+
     def ensure_runtime_environment(self, project_root: Path) -> bool:
         """Ensure codeflash npm package is installed.
 
@@ -2091,6 +2107,8 @@ def ensure_runtime_environment(self, project_root: Path) -> bool:
         """
         from codeflash.cli_cmds.console import logger
 
+        self._detect_node_version()
+
         node_modules_pkg = project_root / "node_modules" / "codeflash"
         if node_modules_pkg.exists():
             logger.debug("codeflash already installed")

codeflash/languages/python/support.py

@@ -3,6 +3,7 @@
 from __future__ import annotations
 
 import logging
+import platform
 from pathlib import Path
 from typing import TYPE_CHECKING, Any
 
@@ -107,6 +108,10 @@ def dir_excludes(self) -> frozenset[str]:
             }
         )
 
+    @property
+    def language_version(self) -> str | None:
+        return platform.python_version()
+
     # === Discovery ===
 
     def discover_functions(