It seems you've removed the parametrization of anyio_backend that ran the tests on both trio and asyncio.

It seems you've removed the parametrization of anyio_backend that ran the tests on both trio and asyncio.

anyio_backend is set to ["trio", "asyncio"] by default:https://github.com/agronholm/anyio/blob/c90169c0bbf0adc53234bde218e265f1b9157797/src/anyio/pytest_plugin.py#L140-L142

Hm you're right, the default for anyio_backend is to use all backends: https://github.com/agronholm/anyio/blob/3.2.0/src/anyio/pytest_plugin.py#L140

By deleting it you're effectively testing on all backends supported by anyio (but also not explicitly passing options).

Thanks. Only thing is the PR title--does this count as "monkeypatching"?

isn't that what this is?

TestClient.async_backend["backend"] = "trio"

isn't that what this is?

🤔 I guess technically it is monkey patching since it's modifying a class attribute at runtime. Always thought of monkey patching as a "bigger hammer" where you modify a method at runtime and potentially do so in a way that wasn't intended by the original author.