# -*- coding: utf-8 -*-
"""Utilities for assertion debugging"""
from __future__ import absolute_import
from __future__ import division
from __future__ import print_function
import pprint
import six
import _pytest._code
from ..compat import Sequence
from _pytest import outcomes
from _pytest._io.saferepr import saferepr
from _pytest.compat import ATTRS_EQ_FIELD
# The _reprcompare attribute on the util module is used by the new assertion
# interpretation code and assertion rewriter to detect this plugin was
# loaded and in turn call the hooks defined here as part of the
# DebugInterpreter.
_reprcompare = None
# the re-encoding is needed for python2 repr
# with non-ascii characters (see issue 877 and 1379)
def ecu(s):
if isinstance(s, bytes):
return s.decode("UTF-8", "replace")
else:
return s
def format_explanation(explanation):
"""This formats an explanation
Normally all embedded newlines are escaped, however there are
three exceptions: \n{, \n} and \n~. The first two are intended
cover nested explanations, see function and attribute explanations
for examples (.visit_Call(), visit_Attribute()). The last one is
for when one explanation needs to span multiple lines, e.g. when
displaying diffs.
"""
explanation = ecu(explanation)
lines = _split_explanation(explanation)
result = _format_lines(lines)
return u"\n".join(result)
def _split_explanation(explanation):
"""Return a list of individual lines in the explanation
This will return a list of lines split on '\n{', '\n}' and '\n~'.
Any other newlines will be escaped and appear in the line as the
literal '\n' characters.
"""
raw_lines = (explanation or u"").split("\n")
lines = [raw_lines[0]]
for values in raw_lines[1:]:
if values and values[0] in ["{", "}", "~", ">"]:
lines.append(values)
else:
lines[-1] += "\\n" + values
return lines
def _format_lines(lines):
"""Format the individual lines
This will replace the '{', '}' and '~' characters of our mini
formatting language with the proper 'where ...', 'and ...' and ' +
...' text, taking care of indentation along the way.
Return a list of formatted lines.
"""
result = lines[:1]
stack = [0]
stackcnt = [0]
for line in lines[1:]:
if line.startswith("{"):
if stackcnt[-1]:
s = u"and "
else:
s = u"where "
stack.append(len(result))
stackcnt[-1] += 1
stackcnt.append(0)
result.append(u" +" + u" " * (len(stack) - 1) + s + line[1:])
elif line.startswith("}"):
stack.pop()
stackcnt.pop()
result[stack[-1]] += line[1:]
else:
assert line[0] in ["~", ">"]
stack[-1] += 1
indent = len(stack) if line.startswith("~") else len(stack) - 1
result.append(u" " * indent + line[1:])
assert len(stack) == 1
return result
# Provide basestring in python3
try:
basestring = basestring
except NameError:
basestring = str
def issequence(x):
return isinstance(x, Sequence) and not isinstance(x, basestring)
def istext(x):
return isinstance(x, basestring)
def isdict(x):
return isinstance(x, dict)
def isset(x):
return isinstance(x, (set, frozenset))
def isdatacls(obj):
return getattr(obj, "__dataclass_fields__", None) is not None
def isattrs(obj):
return getattr(obj, "__attrs_attrs__", None) is not None
def isiterable(obj):
try:
iter(obj)
return not istext(obj)
except TypeError:
return False
def assertrepr_compare(config, op, left, right):
"""Return specialised explanations for some operators/operands"""
width = 80 - 15 - len(op) - 2 # 15 chars indentation, 1 space around op
left_repr = saferepr(left, maxsize=int(width // 2))
right_repr = saferepr(right, maxsize=width - len(left_repr))
summary = u"%s %s %s" % (ecu(left_repr), op, ecu(right_repr))
verbose = config.getoption("verbose")
explanation = None
try:
if op == "==":
if istext(left) and istext(right):
explanation = _diff_text(left, right, verbose)
else:
if issequence(left) and issequence(right):
explanation = _compare_eq_sequence(left, right, verbose)
elif isset(left) and isset(right):
explanation = _compare_eq_set(left, right, verbose)
elif isdict(left) and isdict(right):
explanation = _compare_eq_dict(left, right, verbose)
elif type(left) == type(right) and (isdatacls(left) or isattrs(left)):
type_fn = (isdatacls, isattrs)
explanation = _compare_eq_cls(left, right, verbose, type_fn)
elif verbose > 0:
explanation = _compare_eq_verbose(left, right)
if isiterable(left) and isiterable(right):
expl = _compare_eq_iterable(left, right, verbose)
if explanation is not None:
explanation.extend(expl)
else:
explanation = expl
elif op == "not in":
if istext(left) and istext(right):
explanation = _notin_text(left, right, verbose)
except outcomes.Exit:
raise
except Exception:
explanation = [
u"(pytest_assertion plugin: representation of details failed. "
u"Probably an object has a faulty __repr__.)",
six.text_type(_pytest._code.ExceptionInfo.from_current()),
]
if not explanation:
return None
return [summary] + explanation
def _diff_text(left, right, verbose=0):
"""Return the explanation for the diff between text or bytes.
Unless --verbose is used this will skip leading and trailing
characters which are identical to keep the diff minimal.
If the input are bytes they will be safely converted to text.
"""
from difflib import ndiff
explanation = []
def escape_for_readable_diff(binary_text):
"""
Ensures that the internal string is always valid unicode, converting any bytes safely to valid unicode.
This is done using repr() which then needs post-processing to fix the encompassing quotes and un-escape
newlines and carriage returns (#429).
"""
r = six.text_type(repr(binary_text)[1:-1])
r = r.replace(r"\n", "\n")
r = r.replace(r"\r", "\r")
return r
if isinstance(left, bytes):
left = escape_for_readable_diff(left)
if isinstance(right, bytes):
right = escape_for_readable_diff(right)
if verbose < 1:
i = 0 # just in case left or right has zero length
for i in range(min(len(left), len(right))):
if left[i] != right[i]:
break
if i > 42:
i -= 10 # Provide some context
explanation = [
u"Skipping %s identical leading characters in diff, use -v to show" % i
]
left = left[i:]
right = right[i:]
if len(left) == len(right):
for i in range(len(left)):
if left[-i] != right[-i]:
break
if i > 42:
i -= 10 # Provide some context
explanation += [
u"Skipping {} identical trailing "
u"characters in diff, use -v to show".format(i)
]
left = left[:-i]
right = right[:-i]
keepends = True
if left.isspace() or right.isspace():
left = repr(str(left))
right = repr(str(right))
explanation += [u"Strings contain only whitespace, escaping them using repr()"]
explanation += [
line.strip("\n")
for line in ndiff(left.splitlines(keepends), right.splitlines(keepends))
]
return explanation
def _compare_eq_verbose(left, right):
keepends = True
left_lines = repr(left).splitlines(keepends)
right_lines = repr(right).splitlines(keepends)
explanation = []
explanation += [u"-" + line for line in left_lines]
explanation += [u"+" + line for line in right_lines]
return explanation
def _compare_eq_iterable(left, right, verbose=0):
if not verbose:
return [u"Use -v to get the full diff"]
# dynamic import to speedup pytest
import difflib
try:
left_formatting = pprint.pformat(left).splitlines()
right_formatting = pprint.pformat(right).splitlines()
explanation = [u"Full diff:"]
except Exception:
# hack: PrettyPrinter.pformat() in python 2 fails when formatting items that can't be sorted(), ie, calling
# sorted() on a list would raise. See issue #718.
# As a workaround, the full diff is generated by using the repr() string of each item of each container.
left_formatting = sorted(repr(x) for x in left)
right_formatting = sorted(repr(x) for x in right)
explanation = [u"Full diff (fallback to calling repr on each item):"]
explanation.extend(
line.strip() for line in difflib.ndiff(left_formatting, right_formatting)
)
return explanation
def _compare_eq_sequence(left, right, verbose=0):
explanation = []
len_left = len(left)
len_right = len(right)
for i in range(min(len_left, len_right)):
if left[i] != right[i]:
explanation += [u"At index %s diff: %r != %r" % (i, left[i], right[i])]
break
len_diff = len_left - len_right
if len_diff:
if len_diff > 0:
dir_with_more = "Left"
extra = saferepr(left[len_right])
else:
len_diff = 0 - len_diff
dir_with_more = "Right"
extra = saferepr(right[len_left])
if len_diff == 1:
explanation += [u"%s contains one more item: %s" % (dir_with_more, extra)]
else:
explanation += [
u"%s contains %d more items, first extra item: %s"
% (dir_with_more, len_diff, extra)
]
return explanation
def _compare_eq_set(left, right, verbose=0):
explanation = []
diff_left = left - right
diff_right = right - left
if diff_left:
explanation.append(u"Extra items in the left set:")
for item in diff_left:
explanation.append(saferepr(item))
if diff_right:
explanation.append(u"Extra items in the right set:")
for item in diff_right:
explanation.append(saferepr(item))
return explanation
def _compare_eq_dict(left, right, verbose=0):
explanation = []
set_left = set(left)
set_right = set(right)
common = set_left.intersection(set_right)
same = {k: left[k] for k in common if left[k] == right[k]}
if same and verbose < 2:
explanation += [u"Omitting %s identical items, use -vv to show" % len(same)]
elif same:
explanation += [u"Common items:"]
explanation += pprint.pformat(same).splitlines()
diff = {k for k in common if left[k] != right[k]}
if diff:
explanation += [u"Differing items:"]
for k in diff:
explanation += [saferepr({k: left[k]}) + " != " + saferepr({k: right[k]})]
extra_left = set_left - set_right
len_extra_left = len(extra_left)
if len_extra_left:
explanation.append(
u"Left contains %d more item%s:"
% (len_extra_left, "" if len_extra_left == 1 else "s")
)
explanation.extend(
pprint.pformat({k: left[k] for k in extra_left}).splitlines()
)
extra_right = set_right - set_left
len_extra_right = len(extra_right)
if len_extra_right:
explanation.append(
u"Right contains %d more item%s:"
% (len_extra_right, "" if len_extra_right == 1 else "s")
)
explanation.extend(
pprint.pformat({k: right[k] for k in extra_right}).splitlines()
)
return explanation
def _compare_eq_cls(left, right, verbose, type_fns):
isdatacls, isattrs = type_fns
if isdatacls(left):
all_fields = left.__dataclass_fields__
fields_to_check = [field for field, info in all_fields.items() if info.compare]
elif isattrs(left):
all_fields = left.__attrs_attrs__
fields_to_check = [
field.name for field in all_fields if getattr(field, ATTRS_EQ_FIELD)
]
same = []
diff = []
for field in fields_to_check:
if getattr(left, field) == getattr(right, field):
same.append(field)
else:
diff.append(field)
explanation = []
if same and verbose < 2:
explanation.append(u"Omitting %s identical items, use -vv to show" % len(same))
elif same:
explanation += [u"Matching attributes:"]
explanation += pprint.pformat(same).splitlines()
if diff:
explanation += [u"Differing attributes:"]
for field in diff:
explanation += [
(u"%s: %r != %r") % (field, getattr(left, field), getattr(right, field))
]
return explanation
def _notin_text(term, text, verbose=0):
index = text.find(term)
head = text[:index]
tail = text[index + len(term) :]
correct_text = head + tail
diff = _diff_text(correct_text, text, verbose)
newdiff = [u"%s is contained here:" % saferepr(term, maxsize=42)]
for line in diff:
if line.startswith(u"Skipping"):
continue
if line.startswith(u"- "):
continue
if line.startswith(u"+ "):
newdiff.append(u" " + line[2:])
else:
newdiff.append(line)
return newdiff