litellm/tests/unit/test_constants.py
joshua-berri 4aec80f5ee
fix(mcp): upgrade to MCP SDK 2.3.0 and raise the per-event SSE size cap (#47034)
* fix(mcp): upgrade to MCP SDK 2.3.0 and raise the per-event SSE size cap

MCP SDK 2.x reads Streamable HTTP responses through httpx2's SSE parser,
which rejects any single event over 1 MiB, so a large tools/call result
failed with 'SSE stream ended without a response'. mcp 2.3.0 exposes
max_sse_event_size, and MCPClient now passes a 64 MiB default,
configurable with LITELLM_MCP_MAX_SSE_EVENT_SIZE_BYTES

Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>

* fix(mcp): fall back for invalid SSE event limits

* test(mcp): verify configured SSE limits and recovery

* chore(mcp): remove redundant dependency comment

---------

Co-authored-by: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
Co-authored-by: Joshua Valluru <326636767+joshua-berri@users.noreply.github.com>
2026-10-20 16:00:00 -07:00

367 lines
13 KiB
Python

import ast, asyncio, os
import inspect
import json
import sys
from unittest import mock
import httpx
import pytest
import respx
from fastapi.testclient import TestClient
import importlib
import litellm
from litellm import constants, get_llm_provider, MorphChatConfig
from tests._vcr_conftest_common import install_live_call_probe, record_vcr_outcome
from unittest.mock import patch
_ENV_HELPERS = frozenset(
{"get_env_int", "get_env_float", "get_env_int_in_range", "get_env_int_or_none", "get_env_float_or_none"}
)
def _single_name_target(node: ast.stmt) -> str | None:
if isinstance(node, ast.AnnAssign) and isinstance(node.target, ast.Name):
return node.target.id
if isinstance(node, ast.Assign) and len(node.targets) == 1 and isinstance(node.targets[0], ast.Name):
return node.targets[0].id
return None
def _build_constant_env_var_map() -> dict[str, str]:
"""
Build a mapping of CONSTANT_NAME -> ENV_VAR_NAME by parsing constants.py.
This keeps the test resilient when a constant name and env var name differ
(e.g., aliases like LITELLM_* env vars).
"""
env_var_map: dict[str, str] = {}
constants_source = inspect.getsource(constants)
parsed = ast.parse(constants_source)
for node in parsed.body:
constant_name = _single_name_target(node)
if constant_name is None or not isinstance(node, (ast.Assign, ast.AnnAssign)) or node.value is None:
continue
env_var_name = None
for child in ast.walk(node.value):
if not isinstance(child, ast.Call):
continue
# os.getenv("ENV_NAME", default)
if (
isinstance(child.func, ast.Attribute)
and isinstance(child.func.value, ast.Name)
and child.func.value.id == "os"
and child.func.attr == "getenv"
and len(child.args) >= 1
and isinstance(child.args[0], ast.Constant)
and isinstance(child.args[0].value, str)
):
env_var_name = child.args[0].value
break
# get_env_int("ENV_NAME", default) and its siblings
if (
isinstance(child.func, ast.Name)
and child.func.id in _ENV_HELPERS
and len(child.args) >= 1
and isinstance(child.args[0], ast.Constant)
and isinstance(child.args[0].value, str)
):
env_var_name = child.args[0].value
break
if env_var_name:
env_var_map[constant_name] = env_var_name
return env_var_map
@pytest.mark.parametrize(
("cli_value", "litellm_cli_value", "expected"),
[
("48", None, 48),
(None, "48", 48),
(None, None, 24),
("48", "72", 48),
(" ", None, 24),
("", "48", 48),
],
ids=("canonical-only", "alias-only", "default", "canonical-wins", "blank-canonical", "blank-canonical-alias-set"),
)
def test_cli_jwt_expiration_hours_from_environment(
monkeypatch: pytest.MonkeyPatch,
cli_value: str | None,
litellm_cli_value: str | None,
expected: int,
) -> None:
monkeypatch.delenv("CLI_JWT_EXPIRATION_HOURS", raising=False)
monkeypatch.delenv("LITELLM_CLI_JWT_EXPIRATION_HOURS", raising=False)
try:
if cli_value is not None:
monkeypatch.setenv("CLI_JWT_EXPIRATION_HOURS", cli_value)
if litellm_cli_value is not None:
monkeypatch.setenv("LITELLM_CLI_JWT_EXPIRATION_HOURS", litellm_cli_value)
importlib.reload(litellm.constants)
assert litellm.constants.CLI_JWT_EXPIRATION_HOURS == expected
finally:
monkeypatch.delenv("CLI_JWT_EXPIRATION_HOURS", raising=False)
monkeypatch.delenv("LITELLM_CLI_JWT_EXPIRATION_HOURS", raising=False)
importlib.reload(litellm.constants)
@pytest.mark.parametrize(
("raw", "expected"),
(
(None, 64 * 1024 * 1024),
("", 64 * 1024 * 1024),
("invalid", 64 * 1024 * 1024),
("0", 64 * 1024 * 1024),
("-1", 64 * 1024 * 1024),
("1", 1),
("200000", 200000),
(str(sys.maxsize), sys.maxsize),
(str(sys.maxsize + 1), 64 * 1024 * 1024),
),
)
def test_mcp_sse_event_limit_uses_positive_override_or_default(raw: str | None, expected: int) -> None:
try:
with pytest.MonkeyPatch.context() as environment:
if raw is None:
environment.delenv("LITELLM_MCP_MAX_SSE_EVENT_SIZE_BYTES", raising=False)
else:
environment.setenv("LITELLM_MCP_MAX_SSE_EVENT_SIZE_BYTES", raw)
importlib.reload(constants)
assert constants.MCP_MAX_SSE_EVENT_SIZE_BYTES == expected
finally:
importlib.reload(constants)
def _is_blank(value: object) -> bool:
return isinstance(value, str) and not value.strip()
@pytest.mark.parametrize("blank", ["", " "])
def test_constants_import_treats_blank_env_values_as_unset(blank: str) -> None:
"""
Regression: a numeric knob exported as a blank string (a Helm `value: ""` or an emptied .env
line) raised ValueError while importing litellm.constants, so the proxy crash-looped at boot.
Blank now means unset, so import succeeds with every env-backed constant blank, and every
numeric or optional constant keeps the value it has with the variable absent.
"""
constant_env_vars = _build_constant_env_var_map()
assert {"ROUTER_MAX_FALLBACKS", "LITELLM_MAX_STREAMING_DURATION_SECONDS"} <= constant_env_vars.keys()
env_vars = set(constant_env_vars.values())
try:
with mock.patch.dict(os.environ):
for env_var in env_vars:
os.environ.pop(env_var, None)
importlib.reload(litellm.constants)
unset = {name: getattr(litellm.constants, name) for name in constant_env_vars}
with mock.patch.dict(os.environ, {env_var: blank for env_var in env_vars}):
importlib.reload(litellm.constants)
with_blank_env = {name: getattr(litellm.constants, name) for name in constant_env_vars}
finally:
importlib.reload(litellm.constants)
numeric_or_optional = {name for name, value in unset.items() if value is None or type(value) in (int, float)}
changed = {
name: (unset[name], with_blank_env[name])
for name in numeric_or_optional
if with_blank_env[name] != unset[name] and not _is_blank(with_blank_env[name])
}
assert changed == {}
@pytest.mark.parametrize(
("raw", "expected_timeout", "expected_explicit"),
[
(None, constants.DEFAULT_REQUEST_TIMEOUT_SECONDS, False),
("", constants.DEFAULT_REQUEST_TIMEOUT_SECONDS, False),
(" ", constants.DEFAULT_REQUEST_TIMEOUT_SECONDS, False),
("fast", constants.DEFAULT_REQUEST_TIMEOUT_SECONDS, False),
(" 30 ", 30.0, True),
],
)
def test_request_timeout_counts_as_explicit_only_when_it_parses(
monkeypatch: pytest.MonkeyPatch, raw: str | None, expected_timeout: float, expected_explicit: bool
) -> None:
"""
Regression: a blank REQUEST_TIMEOUT fell back to the 6000s sentinel but was still flagged as
explicitly set, so chat completion() kept the 6000s sentinel instead of its 600s fallback.
"""
if raw is None:
monkeypatch.delenv("REQUEST_TIMEOUT", raising=False)
else:
monkeypatch.setenv("REQUEST_TIMEOUT", raw)
try:
importlib.reload(litellm.constants)
assert litellm.constants.request_timeout == expected_timeout
assert litellm.constants.request_timeout_explicitly_set is expected_explicit
finally:
monkeypatch.undo()
importlib.reload(litellm.constants)
@pytest.fixture()
def _vcr_outcome_gate(request, vcr):
install_live_call_probe(request, vcr)
yield
record_vcr_outcome(request, vcr)
@pytest.fixture(scope="session")
def event_loop():
try:
loop = asyncio.get_running_loop()
except RuntimeError:
loop = asyncio.new_event_loop()
yield loop
loop.close()
@pytest.fixture(scope="function")
def setup_and_teardown(event_loop):
import litellm
original_state = {}
for attr in (
"callbacks",
"success_callback",
"failure_callback",
"_async_success_callback",
"_async_failure_callback",
):
if hasattr(litellm, attr):
val = getattr(litellm, attr)
original_state[attr] = val.copy() if val else []
for attr in _SCALAR_DEFAULTS:
if hasattr(litellm, attr):
original_state[attr] = getattr(litellm, attr)
from litellm.litellm_core_utils.logging_worker import GLOBAL_LOGGING_WORKER
asyncio.run(GLOBAL_LOGGING_WORKER.clear_queue())
importlib.reload(litellm)
asyncio.set_event_loop(event_loop)
yield
for attr, original_value in original_state.items():
if hasattr(litellm, attr):
setattr(litellm, attr, original_value)
pending = asyncio.all_tasks(event_loop)
for task in pending:
task.cancel()
if pending:
event_loop.run_until_complete(asyncio.gather(*pending, return_exceptions=True))
_SCALAR_DEFAULTS = {
"num_retries": getattr(litellm, "num_retries", None),
"set_verbose": getattr(litellm, "set_verbose", False),
"cache": getattr(litellm, "cache", None),
"allowed_fails": getattr(litellm, "allowed_fails", 3),
"disable_aiohttp_transport": getattr(litellm, "disable_aiohttp_transport", False),
"force_ipv4": getattr(litellm, "force_ipv4", False),
"drop_params": getattr(litellm, "drop_params", None),
"modify_params": getattr(litellm, "modify_params", False),
"api_base": getattr(litellm, "api_base", None),
"api_key": getattr(litellm, "api_key", None),
"cohere_key": getattr(litellm, "cohere_key", None),
}
@pytest.fixture
def _populate_known_models_for_morph_tests(monkeypatch: pytest.MonkeyPatch) -> None:
for attr, value in vars(litellm).items():
if attr.endswith("_models") and isinstance(value, set):
monkeypatch.setattr(litellm, attr, value.copy())
monkeypatch.setattr(
litellm,
"models_by_provider",
{provider: models.copy() for provider, models in litellm.models_by_provider.items()},
)
litellm.add_known_models()
@pytest.mark.usefixtures("_vcr_outcome_gate", "setup_and_teardown", "_populate_known_models_for_morph_tests")
def test_morph_config_get_provider_info():
"""Test that MorphChatConfig returns correct provider info."""
config = MorphChatConfig()
# Test with environment variable
with patch.dict(os.environ, {"MORPH_API_KEY": "test-key-from-env"}):
api_base, api_key = config.get_openai_compatible_provider_info(None, None)
assert api_base == "https://api.morphllm.com/v1"
assert api_key == "test-key-from-env"
# Test with passed api_key
api_base, api_key = config.get_openai_compatible_provider_info(None, "direct-key")
assert api_base == "https://api.morphllm.com/v1"
assert api_key == "direct-key"
# Test with custom api_base
api_base, api_key = config.get_openai_compatible_provider_info("https://custom.morph.com", "key")
assert api_base == "https://custom.morph.com"
assert api_key == "key"
@pytest.mark.usefixtures("_vcr_outcome_gate", "setup_and_teardown", "_populate_known_models_for_morph_tests")
def test_morph_get_llm_provider():
"""Test that get_llm_provider correctly identifies morph models."""
# Test with morph/model format
_, custom_llm_provider, _, _ = get_llm_provider("morph/morph-v3-large")
assert custom_llm_provider == "morph"
_, custom_llm_provider, _, _ = get_llm_provider("morph/morph-v3-fast")
assert custom_llm_provider == "morph"
@pytest.mark.usefixtures("_vcr_outcome_gate", "setup_and_teardown", "_populate_known_models_for_morph_tests")
def test_morph_in_provider_lists():
"""Test that morph is included in all necessary provider lists."""
import litellm
from litellm.constants import (
openai_compatible_endpoints,
openai_compatible_providers,
)
# Check morph is in openai_compatible_providers
assert "morph" in openai_compatible_providers
# Check morph endpoint is in openai_compatible_endpoints
assert "https://api.morphllm.com/v1" in openai_compatible_endpoints
# Check morph is in provider_list
assert "morph" in litellm.provider_list
# Check models are in model_list after initialization
assert all(model in litellm.model_list for model in ["morph/morph-v3-large", "morph/morph-v3-fast"])
@pytest.mark.usefixtures("_vcr_outcome_gate", "setup_and_teardown", "_populate_known_models_for_morph_tests")
def test_morph_supported_params():
"""Test that MorphChatConfig returns correct supported parameters."""
config = MorphChatConfig()
supported_params = config.get_supported_openai_params("morph/morph-v3-large")
expected_params = [
"messages",
"model",
"stream",
]
assert all(param in supported_params for param in expected_params)
@pytest.mark.usefixtures("_vcr_outcome_gate", "setup_and_teardown", "_populate_known_models_for_morph_tests")
def test_morph_custom_llm_provider():
"""Test that morph models are correctly identified."""
config = MorphChatConfig()
assert config.custom_llm_provider == "morph"