fix(prompt): warn when custom template directory doesn't exist

openevolve/config.py

@@ -427,9 +427,18 @@ class Config:
     @classmethod
     def from_yaml(cls, path: Union[str, Path]) -> "Config":
         """Load configuration from a YAML file"""
-        with open(path, "r") as f:
+        config_path = Path(path).resolve()
+        with open(config_path, "r") as f:
             config_dict = yaml.safe_load(f)
-        return cls.from_dict(config_dict)
+        config = cls.from_dict(config_dict)
+
+        # Resolve template_dir relative to config file location
+        if config.prompt.template_dir:
+            template_path = Path(config.prompt.template_dir)
+            if not template_path.is_absolute():
+                config.prompt.template_dir = str((config_path.parent / template_path).resolve())
+
+        return config
 
     @classmethod
     def from_dict(cls, config_dict: Dict[str, Any]) -> "Config":

openevolve/prompt/templates.py

@@ -4,9 +4,12 @@
 
 import os
 import json
+import logging
 from pathlib import Path
 from typing import Dict, List, Optional, Union, Any
 
+logger = logging.getLogger(__name__)
+
 # Base system message template for evolution
 BASE_SYSTEM_TEMPLATE = """You are an expert software developer tasked with iteratively improving a codebase.
 Your job is to analyze the current program and suggest improvements based on feedback from previous attempts.
@@ -185,8 +188,13 @@ def __init__(self, custom_template_dir: Optional[str] = None):
         self._load_from_directory(self.default_dir)
 
         # 2. Override with custom templates (if provided)
-        if self.custom_dir and self.custom_dir.exists():
-            self._load_from_directory(self.custom_dir)
+        if self.custom_dir:
+            if self.custom_dir.exists():
+                self._load_from_directory(self.custom_dir)
+            else:
+                logger.warning(
+                    f"Custom template directory does not exist, using default prompt."
+                )
 
     def _load_from_directory(self, directory: Path) -> None:
         """Load all templates and fragments from a directory"""

tests/test_template_dir_resolution.py

@@ -0,0 +1,119 @@
+"""
+Tests for template_dir path resolution
+"""
+
+import unittest
+import tempfile
+import yaml
+from pathlib import Path
+
+from openevolve.config import Config
+
+
+class TestTemplateDirResolution(unittest.TestCase):
+    """Test that template_dir paths are resolved relative to config file location"""
+
+    def test_relative_template_dir_resolved_to_config_location(self):
+        """Relative paths in template_dir should resolve relative to config file"""
+        # Create a temporary directory structure
+        with tempfile.TemporaryDirectory() as tmpdir:
+            config_dir = Path(tmpdir) / "config_subdir"
+            config_dir.mkdir()
+            config_file = config_dir / "test_config.yaml"
+
+            # Write config with relative template_dir
+            config_data = {
+                "prompt": {"template_dir": "templates"},
+                "llm": {"models": [{"name": "gpt-4", "weight": 1.0}]},
+            }
+            with open(config_file, "w") as f:
+                yaml.dump(config_data, f)
+
+            # Load config
+            config = Config.from_yaml(config_file)
+
+            # Template_dir should be resolved relative to config file location
+            expected_path = str((config_dir / "templates").resolve())
+            self.assertEqual(config.prompt.template_dir, expected_path)
+
+    def test_absolute_template_dir_unchanged(self):
+        """Absolute paths in template_dir should remain unchanged"""
+        with tempfile.TemporaryDirectory() as tmpdir:
+            config_file = Path(tmpdir) / "test_config.yaml"
+            absolute_template_path = "/absolute/path/to/templates"
+
+            # Write config with absolute template_dir
+            config_data = {
+                "prompt": {"template_dir": absolute_template_path},
+                "llm": {"models": [{"name": "gpt-4", "weight": 1.0}]},
+            }
+            with open(config_file, "w") as f:
+                yaml.dump(config_data, f)
+
+            # Load config
+            config = Config.from_yaml(config_file)
+
+            # Absolute path should remain unchanged
+            self.assertEqual(config.prompt.template_dir, absolute_template_path)
+
+    def test_null_template_dir_unchanged(self):
+        """Null template_dir should remain None"""
+        with tempfile.TemporaryDirectory() as tmpdir:
+            config_file = Path(tmpdir) / "test_config.yaml"
+
+            # Write config with null template_dir
+            config_data = {
+                "prompt": {"template_dir": None},
+                "llm": {"models": [{"name": "gpt-4", "weight": 1.0}]},
+            }
+            with open(config_file, "w") as f:
+                yaml.dump(config_data, f)
+
+            # Load config
+            config = Config.from_yaml(config_file)
+
+            # None should remain None
+            self.assertIsNone(config.prompt.template_dir)
+
+    def test_nested_relative_template_dir(self):
+        """Nested relative paths should resolve correctly"""
+        with tempfile.TemporaryDirectory() as tmpdir:
+            config_dir = Path(tmpdir) / "configs"
+            config_dir.mkdir()
+            config_file = config_dir / "test_config.yaml"
+
+            # Write config with nested relative path
+            config_data = {
+                "prompt": {"template_dir": "../templates/custom"},
+                "llm": {"models": [{"name": "gpt-4", "weight": 1.0}]},
+            }
+            with open(config_file, "w") as f:
+                yaml.dump(config_data, f)
+
+            # Load config
+            config = Config.from_yaml(config_file)
+
+            # Should resolve to <tmpdir>/templates/custom
+            expected_path = str((config_dir / "../templates/custom").resolve())
+            self.assertEqual(config.prompt.template_dir, expected_path)
+
+    def test_real_example_config(self):
+        """Test with real example config file"""
+        # This test uses the actual llm_prompt_optimization example
+        config_path = "examples/llm_prompt_optimization/config.yaml"
+        if not Path(config_path).exists():
+            self.skipTest(f"Example config not found: {config_path}")
+
+        config = Config.from_yaml(config_path)
+
+        # Should resolve to examples/llm_prompt_optimization/templates
+        expected_dir = Path("examples/llm_prompt_optimization/templates").resolve()
+        actual_dir = Path(config.prompt.template_dir)
+
+        self.assertEqual(actual_dir, expected_dir)
+        # Verify the resolved path is absolute
+        self.assertTrue(actual_dir.is_absolute())
+
+
+if __name__ == "__main__":
+    unittest.main()