AlwaysFailingModel Class — langchain Architecture

Source Code

libs/langchain_v1/tests/unit_tests/agents/middleware/implementations/test_model_retry.py lines 63–87

class AlwaysFailingModel(FakeToolCallingModel):
    """Model that always fails with a specific exception."""

    error_message: str = Field(default="Model error")
    error_type: type[Exception] = Field(default=ValueError)

    def _generate(
        self,
        messages: list[BaseMessage],
        stop: list[str] | None = None,
        run_manager: CallbackManagerForLLMRun | None = None,
        **kwargs: Any,
    ) -> ChatResult:
        """Execute the model and raise exception.

        Args:
            messages: Input messages.
            stop: Optional stop sequences.
            run_manager: Optional callback manager.
            **kwargs: Additional keyword arguments.

        Raises:
            Exception: Always raises the configured exception.
        """
        raise self.error_type(self.error_message)