| 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) |