hermes-agent/tests/test_output_cap_parsing.py
Teknium c7e0bdef9a
fix(agent): stop over-cap max_tokens 400s from death-looping into compression (#55570)
An over-cap model.max_tokens produces a provider 400 that mentions
max_tokens, which trips _CONTEXT_OVERFLOW_PATTERNS and is classified as
context_overflow. On providers whose wording isn't recognized by
parse_available_output_tokens_from_error() (e.g. DashScope/Qwen:
"Range of max_tokens should be [1, 65536]") the smart-retry is skipped
and the error falls into the compression fallback, which re-sends the
same oversized max_tokens, fails identically, and loops until
"cannot compress further" on a tiny conversation (#55546).

Root-cause fix for the whole class, not just DashScope:
- parse_available_output_tokens_from_error(): recognize the DashScope
  "Range of max_tokens should be [1, N]" form and return N (smart-retry
  then caps output and retries WITHOUT compressing).
- new is_output_cap_error(): broader yes/no gate for output-cap 400s.
  In the loop, when the error is output-cap-shaped but unparseable, fail
  fast with an actionable message (lower model.max_tokens) instead of
  routing into compression. Mirrors the existing GPT-5 max_tokens guard.

Real input overflows and GPT-5 unsupported-param 400s are unchanged.
2026-06-30 03:26:41 -07:00

122 lines
5.5 KiB
Python

import pytest
from agent.model_metadata import (
is_output_cap_error,
parse_available_output_tokens_from_error,
)
class TestParseOpenRouterOutputCap:
"""OpenRouter/Nous phrase the output-cap error as a context breakdown."""
def test_openrouter_breakdown_format(self):
msg = ("This endpoint's maximum context length is 200000 tokens. "
"However, you requested about 195000 tokens "
"(150000 of text input, 40000 of tool input, 5000 in the output).")
# available output = 200000 - 150000 - 40000 = 10000
assert parse_available_output_tokens_from_error(msg) == 10000
def test_anthropic_format_still_works(self):
msg = ("max_tokens: 32768 > context_window: 200000 - "
"input_tokens: 190000 = available_tokens: 10000")
assert parse_available_output_tokens_from_error(msg) == 10000
def test_non_output_cap_error_returns_none(self):
assert parse_available_output_tokens_from_error("some unrelated 400 error") is None
def test_breakdown_with_no_room_returns_none(self):
# ctx - text - tool <= 0 -> None (don't return a non-positive cap)
msg = ("maximum context length is 1000 tokens "
"(900 of text input, 200 of tool input, 0 in the output)")
assert parse_available_output_tokens_from_error(msg) is None
class TestParseCharBasedOutputCap:
"""LM Studio / llama.cpp report context in tokens but prompt in characters.
These servers send a hard 400 even on a trivial prompt when the default
output cap equals the context window (#42741): the request asks for the
whole window as output, leaving zero room for input.
"""
def test_char_based_output_cap_format(self):
msg = ("This model's maximum context length is 65536 tokens. However, "
"you requested 65536 output tokens and your prompt contains "
"77409 characters (more than 0 characters, which is the upper "
"bound for 0 input tokens). Please reduce the length of the "
"input prompt or the number of requested output tokens.")
# est input = ceil(77409 / 3) = 25803; available = 65536 - 25803 = 39733
assert parse_available_output_tokens_from_error(msg) == 39733
def test_char_based_leaves_room_for_input(self):
# The whole point: the retried output cap + the estimated input must
# fit inside the reported context window.
ctx = 65536
chars = 77409
available = parse_available_output_tokens_from_error(
f"maximum context length is {ctx} tokens. However, you requested "
f"{ctx} output tokens and your prompt contains {chars} characters."
)
assert available is not None
assert available + (chars + 2) // 3 <= ctx
def test_char_based_no_room_returns_none(self):
# Prompt larger than the window (in tokens) -> not an output-cap fix;
# let the prompt-too-long / compression path handle it.
msg = ("maximum context length is 1000 tokens. However, you requested "
"1000 output tokens and your prompt contains 9000 characters.")
assert parse_available_output_tokens_from_error(msg) is None
class TestParseDashScopeOutputCap:
"""DashScope / Alibaba Cloud (Qwen) reject an over-cap output request with
a bounded range whose upper bound is the real max-output cap (#55546)."""
def test_dashscope_range_format(self):
msg = ("HTTP 400: InternalError.Algo.InvalidParameter: "
"Range of max_tokens should be [1, 65536]")
assert parse_available_output_tokens_from_error(msg) == 65536
def test_dashscope_range_arbitrary_bound(self):
msg = "Range of max_tokens should be [1, 8192]"
assert parse_available_output_tokens_from_error(msg) == 8192
def test_dashscope_range_with_spaces(self):
msg = "range of max_tokens should be [ 1 , 32768 ]"
assert parse_available_output_tokens_from_error(msg) == 32768
class TestIsOutputCapError:
"""`is_output_cap_error` is the broader yes/no gate that keeps an
output-cap 400 out of the compression death-loop even when we can't parse
a number from the provider's wording (#55546)."""
def test_dashscope_is_output_cap(self):
assert is_output_cap_error(
"Range of max_tokens should be [1, 65536]"
) is True
def test_unknown_numeric_max_tokens_cap_is_output_cap(self):
# Provider we don't yet parse a number from, but clearly an output cap.
assert is_output_cap_error("Invalid value: max_tokens should be <= 8192") is True
def test_anthropic_available_tokens_is_output_cap(self):
assert is_output_cap_error(
"max_tokens: 32768 > context_window: 200000 - "
"input_tokens: 190000 = available_tokens: 10000"
) is True
def test_real_input_overflow_is_not_output_cap(self):
# Mentions max_tokens but the INPUT is the problem -> compression path.
assert is_output_cap_error(
"prompt is too long: 250000 tokens > 200000 max_tokens window"
) is False
def test_gpt5_unsupported_param_is_not_output_cap(self):
# format_error caught earlier; must NOT be treated as an output cap.
assert is_output_cap_error(
"Unsupported parameter: 'max_tokens' is not supported with this "
"model. Use 'max_completion_tokens' instead."
) is False
def test_unrelated_error_is_not_output_cap(self):
assert is_output_cap_error("some unrelated 400 error") is False