SimpleFakeChat Class — langchain Architecture

Source Code

libs/core/tests/unit_tests/language_models/chat_models/test_cache.py lines 322–364

    class SimpleFakeChat:
        """Simple fake chat model for testing."""

        def __init__(self, cache: BaseCache) -> None:
            self.cache = cache
            self.response = "hello"

        def _get_llm_string(self) -> str:
            return "test_llm_string"

        def generate_response(self, prompt: str) -> ChatResult:
            """Simulate the cache lookup and generation logic."""
            llm_string = self._get_llm_string()
            prompt_str = dumps([prompt])

            # Check cache first
            cache_val = self.cache.lookup(prompt_str, llm_string)
            if cache_val:
                # This is where our fix should work
                converted_generations = []
                for gen in cache_val:
                    if isinstance(gen, Generation) and not isinstance(
                        gen, ChatGeneration
                    ):
                        # Convert Generation to ChatGeneration by creating an AIMessage
                        chat_gen = ChatGeneration(
                            message=AIMessage(content=gen.text),
                            generation_info=gen.generation_info,
                        )
                        converted_generations.append(chat_gen)
                    else:
                        converted_generations.append(gen)
                return ChatResult(generations=converted_generations)

            # Generate new response
            chat_gen = ChatGeneration(
                message=AIMessage(content=self.response), generation_info={}
            )
            result = ChatResult(generations=[chat_gen])

            # Store in cache
            self.cache.update(prompt_str, llm_string, result.generations)
            return result