Memory update from review of PR #19

[arcanist]

Memory updates from PR #19

Add: Writing tests that need to mock a function imported with from x import y in the module under test.

Type: gotcha

Memory:

When testing Python code that does from module import func (a direct-reference import), patching module.func will NOT affect the already-imported reference. You must patch at the import site — e.g. patch nons.core.node.create_provider, not nons.utils.providers.create_provider. Alternatively, bypass provider creation entirely by patching node.execute directly on each instance.

Rationale:

The agent spent significant debugging effort discovering this. It initially patched nons.utils.providers.create_provider repeatedly in multiple test iterations, but this never worked because node.py holds a direct reference from its from ..utils.providers import create_provider import. The agent ultimately resolved it by patching node.execute on each instance instead. This is a non-obvious Python gotcha that wasted multiple test-run cycles.

Why this is a memory (not a convention update): This is a situational pattern that helps the agent in specific contexts, not a permanent rule for all future code.

Referenced files: nons/core/node.py, tests/test_layer.py, tests/test_node.py

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Add: Setting up or debugging pytest configuration, especially when async tests fail with 'async def functions are not natively supported' despite asyncio_mode being set.

Type: gotcha

Memory:

In Python, a pytest.ini file must use [pytest] as its section header. Using [tool:pytest] (which is correct for setup.cfg) causes pytest to silently ignore all configuration, including asyncio_mode = auto. When pytest.ini exists, it takes precedence over pyproject.toml for pytest config — so a malformed pytest.ini blocks the pyproject.toml settings from being applied.

Rationale:

The agent discovered a pre-existing infrastructure bug: pytest.ini had [tool:pytest] instead of [pytest], which meant asyncio_mode = auto was never applied even though the setting existed in pyproject.toml as well. This caused 143+ async test failures that went undetected. Not obvious from reading the file — the header looks like valid INI syntax.

Why this is a memory (not a convention update): This is a situational pattern that helps the agent in specific contexts, not a permanent rule for all future code.

Referenced files: pytest.ini

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Sessions: d55fa65f-1b03-461d-a5ab-9c4ce1f31a75

Merge to apply. Close to discard.