"""A fake callback handler for testing purposes.""" from typing import Any, Dict, List, Union from pydantic import BaseModel from langchain.callbacks.base import AsyncCallbackHandler, BaseCallbackHandler from langchain.schema import AgentAction, AgentFinish, LLMResult class BaseFakeCallbackHandler(BaseModel): """Base fake callback handler for testing.""" starts: int = 0 ends: int = 0 errors: int = 0 text: int = 0 ignore_llm_: bool = False ignore_chain_: bool = False ignore_agent_: bool = False always_verbose_: bool = False @property def always_verbose(self) -> bool: """Whether to call verbose callbacks even if verbose is False.""" return self.always_verbose_ @property def ignore_llm(self) -> bool: """Whether to ignore LLM callbacks.""" return self.ignore_llm_ @property def ignore_chain(self) -> bool: """Whether to ignore chain callbacks.""" return self.ignore_chain_ @property def ignore_agent(self) -> bool: """Whether to ignore agent callbacks.""" return self.ignore_agent_ # add finer-grained counters for easier debugging of failing tests chain_starts: int = 0 chain_ends: int = 0 llm_starts: int = 0 llm_ends: int = 0 llm_streams: int = 0 tool_starts: int = 0 tool_ends: int = 0 agent_ends: int = 0 class FakeCallbackHandler(BaseFakeCallbackHandler, BaseCallbackHandler): """Fake callback handler for testing.""" def on_llm_start( self, serialized: Dict[str, Any], prompts: List[str], **kwargs: Any ) -> None: """Run when LLM starts running.""" self.llm_starts += 1 self.starts += 1 def on_llm_new_token(self, token: str, **kwargs: Any) -> None: """Run when LLM generates a new token.""" self.llm_streams += 1 def on_llm_end(self, response: LLMResult, **kwargs: Any) -> None: """Run when LLM ends running.""" self.llm_ends += 1 self.ends += 1 def on_llm_error( self, error: Union[Exception, KeyboardInterrupt], **kwargs: Any ) -> None: """Run when LLM errors.""" self.errors += 1 def on_chain_start( self, serialized: Dict[str, Any], inputs: Dict[str, Any], **kwargs: Any ) -> None: """Run when chain starts running.""" self.chain_starts += 1 self.starts += 1 def on_chain_end(self, outputs: Dict[str, Any], **kwargs: Any) -> None: """Run when chain ends running.""" self.chain_ends += 1 self.ends += 1 def on_chain_error( self, error: Union[Exception, KeyboardInterrupt], **kwargs: Any ) -> None: """Run when chain errors.""" self.errors += 1 def on_tool_start( self, serialized: Dict[str, Any], input_str: str, **kwargs: Any ) -> None: """Run when tool starts running.""" self.tool_starts += 1 self.starts += 1 def on_tool_end(self, output: str, **kwargs: Any) -> None: """Run when tool ends running.""" self.tool_ends += 1 self.ends += 1 def on_tool_error( self, error: Union[Exception, KeyboardInterrupt], **kwargs: Any ) -> None: """Run when tool errors.""" self.errors += 1 def on_text(self, text: str, **kwargs: Any) -> None: """Run when agent is ending.""" self.text += 1 def on_agent_finish(self, finish: AgentFinish, **kwargs: Any) -> None: """Run when agent ends running.""" self.agent_ends += 1 self.ends += 1 def on_agent_action(self, action: AgentAction, **kwargs: Any) -> Any: """Run on agent action.""" self.tool_starts += 1 self.starts += 1 class FakeAsyncCallbackHandler(BaseFakeCallbackHandler, AsyncCallbackHandler): """Fake async callback handler for testing.""" async def on_llm_start( self, serialized: Dict[str, Any], prompts: List[str], **kwargs: Any ) -> None: """Run when LLM starts running.""" self.llm_starts += 1 self.starts += 1 async def on_llm_new_token(self, token: str, **kwargs: Any) -> None: """Run when LLM generates a new token.""" self.llm_streams += 1 async def on_llm_end(self, response: LLMResult, **kwargs: Any) -> None: """Run when LLM ends running.""" self.llm_ends += 1 self.ends += 1 async def on_llm_error( self, error: Union[Exception, KeyboardInterrupt], **kwargs: Any ) -> None: """Run when LLM errors.""" self.errors += 1 async def on_chain_start( self, serialized: Dict[str, Any], inputs: Dict[str, Any], **kwargs: Any ) -> None: """Run when chain starts running.""" self.chain_starts += 1 self.starts += 1 async def on_chain_end(self, outputs: Dict[str, Any], **kwargs: Any) -> None: """Run when chain ends running.""" self.chain_ends += 1 self.ends += 1 async def on_chain_error( self, error: Union[Exception, KeyboardInterrupt], **kwargs: Any ) -> None: """Run when chain errors.""" self.errors += 1 async def on_tool_start( self, serialized: Dict[str, Any], input_str: str, **kwargs: Any ) -> None: """Run when tool starts running.""" self.tool_starts += 1 self.starts += 1 async def on_tool_end(self, output: str, **kwargs: Any) -> None: """Run when tool ends running.""" self.tool_ends += 1 self.ends += 1 async def on_tool_error( self, error: Union[Exception, KeyboardInterrupt], **kwargs: Any ) -> None: """Run when tool errors.""" self.errors += 1 async def on_text(self, text: str, **kwargs: Any) -> None: """Run when agent is ending.""" self.text += 1 async def on_agent_finish(self, finish: AgentFinish, **kwargs: Any) -> None: """Run when agent ends running.""" self.agent_ends += 1 self.ends += 1 async def on_agent_action(self, action: AgentAction, **kwargs: Any) -> None: """Run on agent action.""" self.tool_starts += 1 self.starts += 1