pytest2/py/_plugin/pytest_assertion.py

75 lines
2.7 KiB
Python

import py
import sys
def pytest_addoption(parser):
group = parser.getgroup("debugconfig")
group._addoption('--no-assert', action="store_true", default=False,
dest="noassert",
help="disable python assert expression reinterpretation."),
def pytest_configure(config):
if not config.getvalue("noassert") and not config.getvalue("nomagic"):
warn_about_missing_assertion()
config._oldassertion = py.builtin.builtins.AssertionError
py.builtin.builtins.AssertionError = py.code._AssertionError
def pytest_unconfigure(config):
if hasattr(config, '_oldassertion'):
py.builtin.builtins.AssertionError = config._oldassertion
del config._oldassertion
def warn_about_missing_assertion():
try:
assert False
except AssertionError:
pass
else:
py.std.warnings.warn("Assertions are turned off!"
" (are you using python -O?)")
def pytest_assert_compare(op, left, right):
"""Make a specialised explanation for comapare equal"""
if op != '==' or type(left) != type(right):
return None
explanation = []
left_repr = py.io.saferepr(left, maxsize=30)
right_repr = py.io.saferepr(right, maxsize=30)
explanation += ['%s == %s' % (left_repr, right_repr)]
issquence = lambda x: isinstance(x, (list, tuple))
istext = lambda x: isinstance(x, basestring)
isdict = lambda x: isinstance(x, dict)
if istext(left):
explanation += [line.strip('\n') for line in
py.std.difflib.ndiff(left.splitlines(), right.splitlines())]
elif issquence(left):
explanation += _compare_eq_sequence(left, right)
elif isdict(left):
explanation += _pprint_diff(left, right)
else:
return None # No specialised knowledge
return explanation
def _compare_eq_sequence(left, right):
explanation = []
for i in xrange(min(len(left), len(right))):
if left[i] != right[i]:
explanation += ['First differing item %s: %s != %s' %
(i, left[i], right[i])]
break
if len(left) > len(right):
explanation += ['Left contains more items, '
'first extra item: %s' % left[len(right)]]
elif len(left) < len(right):
explanation += ['Right contains more items, '
'first extra item: %s' % right[len(right)]]
return explanation + _pprint_diff(left, right)
def _pprint_diff(left, right):
"""Make explanation using pprint and difflib"""
return [line.strip('\n') for line in
py.std.difflib.ndiff(py.std.pprint.pformat(left).splitlines(),
py.std.pprint.pformat(right).splitlines())]