Asserting deprecation and other warnings¶
The recwarn function argument¶
You can use the recwarn
funcarg to assert that code triggers
warnings through the Python warnings system. Here is a simple
self-contained test:
# content of test_recwarn.py
def test_hello(recwarn):
from warnings import warn
warn("hello", DeprecationWarning)
w = recwarn.pop(DeprecationWarning)
assert issubclass(w.category, DeprecationWarning)
assert 'hello' in str(w.message)
assert w.filename
assert w.lineno
The recwarn
function argument provides these methods:
pop(category=None)
: return last warning matching the category.clear()
: clear list of warnings
Ensuring a function triggers a deprecation warning¶
You can also call a global helper for checking that a certain function call triggers a Deprecation warning:
import pytest
def test_global():
pytest.deprecated_call(myfunction, 17)