* fix(agent): stop executing illustrative Markdown fences as tool calls for native function-calling models
_resolve_tool_blocks fell back to the textual parse_tool_blocks() fenced-block
parser whenever a model produced no native tool_calls, regardless of whether
that model has a reliable native function-calling channel. Native models
(GPT/Claude/Grok/Qwen3/DeepSeek-V, etc. - _is_api_model true) commonly write
illustrative ```bash/```python/```json examples in guide-only prose; the
fallback parser matched these and executed them as real commands, sometimes
looping for several rounds as the model tried to clarify with more examples
(#3222).
Restrict the textual fenced-block fallback to non-native models, which rely
on it as their only tool-invocation channel. Native models are trusted to use
their structured tool_calls channel for real invocations; when they don't
emit one, a bare fence in their response is prose, not an action. The native
tool_calls path itself is untouched.
This sits one layer below #3088's guide-only policy enforcement: that PR
blocks tool exposure/execution on explicit no-tools requests, while this fixes
the parser so ordinary illustrative fences are never misread as calls in the
first place, on any turn.
* fix(agent): gate only the fenced-example pattern for native models, preserve DSML/invoke recovery and persistence
_resolve_tool_blocks previously short-circuited the entire textual parser
(tool_blocks = [] if is_api_model else parse_tool_blocks(...)) for native
function-calling models with no native tool_calls. That also dropped Patterns
2-5 (explicit [TOOL_CALL]/<invoke>/<tool_code>/DSML markup leaked into content
as text), which are real calls a model couldn't emit on its structured channel
(e.g. DeepSeek-V falling back to DSML), not illustrative examples.
parse_tool_blocks/strip_tool_blocks now take a skip_fenced flag that gates ONLY
Pattern 1 (the fenced ```bash/```python/```json block matcher). _resolve_tool_blocks
passes skip_fenced=is_api_model so fenced examples stop being executed for
native models while [TOOL_CALL]/<invoke>/<tool_code>/DSML stay fully active and
recoverable. cleaned_round mirrors the same gate when persisting round text, so
an illustrative fence that wasn't executed isn't stripped from saved/reloaded
history either (it was streaming once and then disappearing on reload).
This file documents the shared test helpers and the review expectations that go
with them. The suite is being refactored incrementally, so this is a working
reference for that effort - not a claim that the suite is already fully
organized. Read it before adding a new helper or before reviewing a PR that
touches tests/helpers/.
For the broader rules - test taxonomy, determinism/isolation rules, the
behavioral-vs-source-text policy, and helper/factory extraction rules - see
TESTING_STANDARD.md. This file is the concrete helper
reference; that file is the standard the refactor works toward.
Core principles
Keep PRs small and homogeneous: one kind of change per PR.
Prefer explicit local setup over hidden global fixtures.
Avoid expanding the root conftest.py unless absolutely necessary.
Do not mix file moves with logic changes in the same PR.
Do not weaken tests with skip/xfail just to make CI pass.
Validate the focused files you changed, plus any neighboring or
order-sensitive groups they interact with.
Helper conventions
The helpers below live under tests/helpers/. They exist to remove repeated
boilerplate that already appeared across multiple tests. Reach for one only when
your test matches its intended use; do not stretch a helper to cover a new case.
tests.helpers.cli_loader.load_script
Use when a test needs to import a script under scripts/ without repeating
SourceFileLoader / importlib.util boilerplate.
Intended for script/CLI tests that load a single file from scripts/.
Not for arbitrary package imports - use a normal import for those.
When migrating an existing test to it, keep the existing stubs and assertions
unchanged. Any sys.modules stubs the script needs at import time must still
be injected (e.g. via monkeypatch) before calling load_script.
tests.helpers.import_state.clear_module
Use when a test must drop one cached module and its parent-package attribute
before a fresh import.
Clears sys.modules[name].
Clears the parent-package attribute when present.
Good replacement for local sys.modules.pop(...) + delattr(parent, child)
blocks.
tests.helpers.import_state.preserve_import_state
Use when a test temporarily installs stubs into sys.modules and needs
deterministic cleanup afterward.
Context manager: restores both sys.modules entries and parent-package
attributes on exit (normal or exception).
Useful around module-level stubs or temporary imports.
Prefer narrow, explicit module names over broad ones.
Lucas Daniel
0a324f20d2