vibe/tests/stubs/fake_backend.py
Mathias Gesbert 2e1e15120d v1.2.2
Co-Authored-By: Quentin Torroba <quentin.torroba@mistral.ai>
Co-Authored-By: Michel Thomazo <michel.thomazo@mistral.ai>
2025-12-22 13:41:25 +01:00

139 lines
4.4 KiB
Python

from __future__ import annotations
from collections.abc import AsyncGenerator, Callable, Iterable
from typing import cast
from tests.mock.utils import mock_llm_chunk
from vibe.core.types import LLMChunk, LLMMessage, Role
class FakeBackend:
"""Minimal async backend stub to drive Agent.act without network.
Provide a finite sequence of LLMResult objects to be returned by
`complete`. When exhausted, returns an empty assistant message.
"""
def __init__(
self,
chunks: LLMChunk
| Iterable[LLMChunk]
| Iterable[Iterable[LLMChunk]]
| None = None,
*,
token_counter: Callable[[list[LLMMessage]], int] | None = None,
exception_to_raise: Exception | None = None,
) -> None:
"""Fake backend that will output the given chunks in the order they are given.
chunks: A single chunk, a sequence of chunks, or a sequence of sequences of chunks.
A single chunk would be outputted as such in complete / complete_streaming
A sequence of chunks will is considered a single stream: a completion would output
all chunks (either streaming or in an aggregated way)
A sequence of sequences of chunks is considered a list of streams: each completion
will output a stream (either streaming or in an aggregated way)
"""
self._requests_messages: list[list[LLMMessage]] = []
self._requests_extra_headers: list[dict[str, str] | None] = []
self._count_tokens_calls: list[list[LLMMessage]] = []
self._token_counter = token_counter or self._default_token_counter
self._exception_to_raise = exception_to_raise
self._streams: list[list[LLMChunk]]
if chunks is None:
self._streams = []
return
if isinstance(chunks, LLMChunk):
self._streams = [[chunks]]
return
if all(isinstance(chunk, LLMChunk) for chunk in chunks):
self._streams = [[cast(LLMChunk, chunk) for chunk in chunks]]
return
if any(isinstance(chunk, LLMChunk) for chunk in chunks):
raise TypeError(
f"Invalid type for chunks, expected a value of type "
f"LLMChunk | Iterable[LLMChunk] | Iterable[Iterable[LLMChunk]], got {chunks!r}"
)
chunks = cast(Iterable[Iterable[LLMChunk]], chunks)
self._streams = [[chunk for chunk in stream] for stream in chunks]
@property
def requests_messages(self) -> list[list[LLMMessage]]:
return self._requests_messages
@property
def requests_extra_headers(self) -> list[dict[str, str] | None]:
return self._requests_extra_headers
@staticmethod
def _default_token_counter(messages: list[LLMMessage]) -> int:
return 1
async def __aenter__(self):
return self
async def __aexit__(self, exc_type, exc_val, exc_tb):
return None
async def complete(
self,
*,
model,
messages,
temperature,
tools,
tool_choice,
extra_headers,
max_tokens,
) -> LLMChunk:
if self._exception_to_raise:
raise self._exception_to_raise
self._requests_messages.append(messages)
self._requests_extra_headers.append(extra_headers)
if self._streams:
stream = self._streams.pop(0)
chunk_agg = LLMChunk(message=LLMMessage(role=Role.assistant))
for chunk in stream:
chunk_agg += chunk
return chunk_agg
return mock_llm_chunk(content="")
async def complete_streaming(
self,
*,
model,
messages,
temperature,
tools,
tool_choice,
extra_headers,
max_tokens,
) -> AsyncGenerator[LLMChunk]:
if self._exception_to_raise:
raise self._exception_to_raise
self._requests_messages.append(messages)
self._requests_extra_headers.append(extra_headers)
if self._streams:
stream = list(self._streams.pop(0))
else:
stream = [mock_llm_chunk(content="")]
for chunk in stream:
yield chunk
async def count_tokens(
self,
*,
model,
messages,
temperature=0.0,
tools,
tool_choice=None,
extra_headers,
) -> int:
self._count_tokens_calls.append(list(messages))
return self._token_counter(messages)