cpython/Lib/test/support/testcase.py

66 lines
2.3 KiB
Python

from math import copysign, isnan
class ExceptionIsLikeMixin:
def assertExceptionIsLike(self, exc, template):
"""
Passes when the provided `exc` matches the structure of `template`.
Individual exceptions don't have to be the same objects or even pass
an equality test: they only need to be the same type and contain equal
`exc_obj.args`.
"""
if exc is None and template is None:
return
if template is None:
self.fail(f"unexpected exception: {exc}")
if exc is None:
self.fail(f"expected an exception like {template!r}, got None")
if not isinstance(exc, ExceptionGroup):
self.assertEqual(exc.__class__, template.__class__)
self.assertEqual(exc.args[0], template.args[0])
else:
self.assertEqual(exc.message, template.message)
self.assertEqual(len(exc.exceptions), len(template.exceptions))
for e, t in zip(exc.exceptions, template.exceptions):
self.assertExceptionIsLike(e, t)
class FloatsAreIdenticalMixin:
def assertFloatsAreIdentical(self, x, y):
"""Fail unless floats x and y are identical, in the sense that:
(1) both x and y are nans, or
(2) both x and y are infinities, with the same sign, or
(3) both x and y are zeros, with the same sign, or
(4) x and y are both finite and nonzero, and x == y
"""
msg = 'floats {!r} and {!r} are not identical'
if isnan(x) or isnan(y):
if isnan(x) and isnan(y):
return
elif x == y:
if x != 0.0:
return
# both zero; check that signs match
elif copysign(1.0, x) == copysign(1.0, y):
return
else:
msg += ': zeros have different signs'
self.fail(msg.format(x, y))
class ComplexesAreIdenticalMixin(FloatsAreIdenticalMixin):
def assertComplexesAreIdentical(self, x, y):
"""Fail unless complex numbers x and y have equal values and signs.
In particular, if x and y both have real (or imaginary) part
zero, but the zeros have different signs, this test will fail.
"""
self.assertFloatsAreIdentical(x.real, y.real)
self.assertFloatsAreIdentical(x.imag, y.imag)