AgentFarm

Dependency Injection Improvements

This document explains recent refactors that introduce dependency injection (DI) for configuration and improve service injection patterns across the project. The primary goal is to reduce direct environment and concrete dependency coupling, improving testability, modularity, and maintainability.

What Changed

  • Added IConfigService interface and a default EnvConfigService implementation.
    • Location: farm/core/services/interfaces.py, farm/core/services/implementations.py
    • Exported via farm/core/services/__init__.py
  • Refactored modules that previously read environment variables directly to accept a config_service (or use EnvConfigService by default):
    • farm/charts/llm_client.py now accepts config_service and no longer reads OPENAI_API_KEY directly.
    • farm/analysis/registry.register_modules accepts config_service and no longer reads FARM_ANALYSIS_MODULES directly.
    • farm/analysis/service.AnalysisService injects EnvConfigService into register_modules.
    • scripts/analysis_config.py injects EnvConfigService into register_modules.
    • farm/utils/run_analysis.setup_environment uses IConfigService to validate existence of OPENAI_API_KEY.
  • A lightweight singleton farm.analysis.null_module.null_module was exposed to make testing the registry easier.

These changes align with SRP, DIP, and KISS principles and prefactor the codebase for broader DI adoption.

New Interfaces and Implementations

  • IConfigService
    • Methods:
      • get(key: str, default: Optional[str] = None) -> Optional[str]
      • get_analysis_module_paths(env_var: str = "FARM_ANALYSIS_MODULES") -> List[str]
      • get_openai_api_key() -> Optional[str]
  • EnvConfigService (default)
    • Reads from environment variables via os.getenv and implements IConfigService.

Updated APIs

  • LLMClient
    • Before: LLMClient(api_key: Optional[str] = None) reads env directly when api_key not provided.
    • Now: LLMClient(api_key: Optional[str] = None, config_service: Optional[IConfigService] = None)
      • If api_key is None, the client uses config_service.get_openai_api_key().
      • Defaults to EnvConfigService() when not provided.
  • farm.analysis.registry.register_modules
    • Before: register_modules(config_env_var: str = "FARM_ANALYSIS_MODULES") reads env directly.
    • Now: register_modules(config_env_var: str = "FARM_ANALYSIS_MODULES", *, config_service: Optional[IConfigService] = None)
      • Uses config_service.get_analysis_module_paths(config_env_var).
      • Defaults to EnvConfigService() when not provided.
      • Will attempt to register all configured modules; if none successfully register, it falls back to the built-in dominance module.
  • AnalysisService and scripts/analysis_config.py
    • Both now call register_modules(config_service=EnvConfigService()).
  • utils/run_analysis.setup_environment
    • Before: validated OPENAI_API_KEY via os.getenv.
    • Now: validates via config_service.get_openai_api_key() and defaults to EnvConfigService().

Example Usage

Injecting a custom config service for testing or alternative configuration sources:

from farm.core.services import IConfigService
from farm.charts.llm_client import LLMClient
from farm.analysis.registry import register_modules


class StaticConfig(IConfigService):
    def __init__(self, api_key: str, modules: list[str] = None):
        self._api_key = api_key
        self._modules = modules or []

    def get(self, key: str, default: str | None = None) -> str | None:
        return default

    def get_analysis_module_paths(self, env_var: str = "FARM_ANALYSIS_MODULES") -> list[str]:
        return list(self._modules)

    def get_openai_api_key(self) -> str | None:
        return self._api_key


cfg = StaticConfig(api_key="sk-test", modules=["farm.analysis.null_module.null_module"])
register_modules(config_service=cfg)
client = LLMClient(config_service=cfg)

Backward Compatibility

  • Backward-compatibility fallbacks have been removed to enforce explicit DI usage:
    • LLMClient now requires an IConfigService (and optional explicit api_key).
    • register_modules requires an IConfigService and no longer falls back to a built-in module.

Testing

New tests validate the DI behavior:

  • tests/test_config_service.py covers EnvConfigService behaviors.
  • tests/test_analysis_registry_di.py ensures the registry uses an injected module list provider.

To run only the new tests:

python3 -m pytest -q tests/test_config_service.py tests/test_analysis_registry_di.py

Note: The full test suite depends on additional packages (e.g., pydantic, psutil, stable_baselines3). Those are unrelated to these DI changes.

Migration Notes

  • Code must now inject IConfigService explicitly:
    • For LLMClient, pass config_service and optionally api_key.
    • For analysis registration, call register_modules(config_service=...) with module paths supplied by your service.
    • Replace any remaining direct env reads with IConfigService accessors.
  • farm/core/services/interfaces.py
  • farm/core/services/implementations.py
  • farm/core/services/__init__.py
  • farm/charts/llm_client.py
  • farm/charts/chart_analyzer.py
  • farm/analysis/registry.py
  • farm/analysis/service.py
  • farm/utils/run_analysis.py
  • scripts/analysis_config.py