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matekasse/venv/lib/python3.11/site-packages/_pytest/assertion/util.py
2023-07-28 23:30:45 +02:00

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Python

"""Utilities for assertion debugging."""
import collections.abc
import os
import pprint
from typing import AbstractSet
from typing import Any
from typing import Callable
from typing import Iterable
from typing import List
from typing import Mapping
from typing import Optional
from typing import Sequence
from unicodedata import normalize
import _pytest._code
from _pytest import outcomes
from _pytest._io.saferepr import _pformat_dispatch
from _pytest._io.saferepr import saferepr
from _pytest._io.saferepr import saferepr_unlimited
from _pytest.config import Config
# 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: Optional[Callable[[str, object, object], Optional[str]]] = None
# Works similarly as _reprcompare attribute. Is populated with the hook call
# when pytest_runtest_setup is called.
_assertion_pass: Optional[Callable[[int, str, str], None]] = None
# Config object which is assigned during pytest_runtest_protocol.
_config: Optional[Config] = None
def format_explanation(explanation: str) -> str:
r"""Format 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.
"""
lines = _split_explanation(explanation)
result = _format_lines(lines)
return "\n".join(result)
def _split_explanation(explanation: str) -> List[str]:
r"""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 "").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: Sequence[str]) -> List[str]:
"""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 = list(lines[:1])
stack = [0]
stackcnt = [0]
for line in lines[1:]:
if line.startswith("{"):
if stackcnt[-1]:
s = "and "
else:
s = "where "
stack.append(len(result))
stackcnt[-1] += 1
stackcnt.append(0)
result.append(" +" + " " * (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(" " * indent + line[1:])
assert len(stack) == 1
return result
def issequence(x: Any) -> bool:
return isinstance(x, collections.abc.Sequence) and not isinstance(x, str)
def istext(x: Any) -> bool:
return isinstance(x, str)
def isdict(x: Any) -> bool:
return isinstance(x, dict)
def isset(x: Any) -> bool:
return isinstance(x, (set, frozenset))
def isnamedtuple(obj: Any) -> bool:
return isinstance(obj, tuple) and getattr(obj, "_fields", None) is not None
def isdatacls(obj: Any) -> bool:
return getattr(obj, "__dataclass_fields__", None) is not None
def isattrs(obj: Any) -> bool:
return getattr(obj, "__attrs_attrs__", None) is not None
def isiterable(obj: Any) -> bool:
try:
iter(obj)
return not istext(obj)
except TypeError:
return False
def has_default_eq(
obj: object,
) -> bool:
"""Check if an instance of an object contains the default eq
First, we check if the object's __eq__ attribute has __code__,
if so, we check the equally of the method code filename (__code__.co_filename)
to the default one generated by the dataclass and attr module
for dataclasses the default co_filename is <string>, for attrs class, the __eq__ should contain "attrs eq generated"
"""
# inspired from https://github.com/willmcgugan/rich/blob/07d51ffc1aee6f16bd2e5a25b4e82850fb9ed778/rich/pretty.py#L68
if hasattr(obj.__eq__, "__code__") and hasattr(obj.__eq__.__code__, "co_filename"):
code_filename = obj.__eq__.__code__.co_filename
if isattrs(obj):
return "attrs generated eq" in code_filename
return code_filename == "<string>" # data class
return True
def assertrepr_compare(
config, op: str, left: Any, right: Any, use_ascii: bool = False
) -> Optional[List[str]]:
"""Return specialised explanations for some operators/operands."""
verbose = config.getoption("verbose")
# Strings which normalize equal are often hard to distinguish when printed; use ascii() to make this easier.
# See issue #3246.
use_ascii = (
isinstance(left, str)
and isinstance(right, str)
and normalize("NFD", left) == normalize("NFD", right)
)
if verbose > 1:
left_repr = saferepr_unlimited(left, use_ascii=use_ascii)
right_repr = saferepr_unlimited(right, use_ascii=use_ascii)
else:
# XXX: "15 chars indentation" is wrong
# ("E AssertionError: assert "); should use term width.
maxsize = (
80 - 15 - len(op) - 2
) // 2 # 15 chars indentation, 1 space around op
left_repr = saferepr(left, maxsize=maxsize, use_ascii=use_ascii)
right_repr = saferepr(right, maxsize=maxsize, use_ascii=use_ascii)
summary = f"{left_repr} {op} {right_repr}"
explanation = None
try:
if op == "==":
explanation = _compare_eq_any(left, right, verbose)
elif op == "not in":
if istext(left) and istext(right):
explanation = _notin_text(left, right, verbose)
except outcomes.Exit:
raise
except Exception:
explanation = [
"(pytest_assertion plugin: representation of details failed: {}.".format(
_pytest._code.ExceptionInfo.from_current()._getreprcrash()
),
" Probably an object has a faulty __repr__.)",
]
if not explanation:
return None
return [summary] + explanation
def _compare_eq_any(left: Any, right: Any, verbose: int = 0) -> List[str]:
explanation = []
if istext(left) and istext(right):
explanation = _diff_text(left, right, verbose)
else:
from _pytest.python_api import ApproxBase
if isinstance(left, ApproxBase) or isinstance(right, ApproxBase):
# Although the common order should be obtained == expected, this ensures both ways
approx_side = left if isinstance(left, ApproxBase) else right
other_side = right if isinstance(left, ApproxBase) else left
explanation = approx_side._repr_compare(other_side)
elif type(left) == type(right) and (
isdatacls(left) or isattrs(left) or isnamedtuple(left)
):
# Note: unlike dataclasses/attrs, namedtuples compare only the
# field values, not the type or field names. But this branch
# intentionally only handles the same-type case, which was often
# used in older code bases before dataclasses/attrs were available.
explanation = _compare_eq_cls(left, right, verbose)
elif 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)
if isiterable(left) and isiterable(right):
expl = _compare_eq_iterable(left, right, verbose)
explanation.extend(expl)
return explanation
def _diff_text(left: str, right: str, verbose: int = 0) -> List[str]:
"""Return the explanation for the diff between text.
Unless --verbose is used this will skip leading and trailing
characters which are identical to keep the diff minimal.
"""
from difflib import ndiff
explanation: List[str] = []
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 = [
"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 += [
"Skipping {} identical trailing "
"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 += ["Strings contain only whitespace, escaping them using repr()"]
# "right" is the expected base against which we compare "left",
# see https://github.com/pytest-dev/pytest/issues/3333
explanation += [
line.strip("\n")
for line in ndiff(right.splitlines(keepends), left.splitlines(keepends))
]
return explanation
def _surrounding_parens_on_own_lines(lines: List[str]) -> None:
"""Move opening/closing parenthesis/bracket to own lines."""
opening = lines[0][:1]
if opening in ["(", "[", "{"]:
lines[0] = " " + lines[0][1:]
lines[:] = [opening] + lines
closing = lines[-1][-1:]
if closing in [")", "]", "}"]:
lines[-1] = lines[-1][:-1] + ","
lines[:] = lines + [closing]
def _compare_eq_iterable(
left: Iterable[Any], right: Iterable[Any], verbose: int = 0
) -> List[str]:
if verbose <= 0 and not running_on_ci():
return ["Use -v to get more diff"]
# dynamic import to speedup pytest
import difflib
left_formatting = pprint.pformat(left).splitlines()
right_formatting = pprint.pformat(right).splitlines()
# Re-format for different output lengths.
lines_left = len(left_formatting)
lines_right = len(right_formatting)
if lines_left != lines_right:
left_formatting = _pformat_dispatch(left).splitlines()
right_formatting = _pformat_dispatch(right).splitlines()
if lines_left > 1 or lines_right > 1:
_surrounding_parens_on_own_lines(left_formatting)
_surrounding_parens_on_own_lines(right_formatting)
explanation = ["Full diff:"]
# "right" is the expected base against which we compare "left",
# see https://github.com/pytest-dev/pytest/issues/3333
explanation.extend(
line.rstrip() for line in difflib.ndiff(right_formatting, left_formatting)
)
return explanation
def _compare_eq_sequence(
left: Sequence[Any], right: Sequence[Any], verbose: int = 0
) -> List[str]:
comparing_bytes = isinstance(left, bytes) and isinstance(right, bytes)
explanation: List[str] = []
len_left = len(left)
len_right = len(right)
for i in range(min(len_left, len_right)):
if left[i] != right[i]:
if comparing_bytes:
# when comparing bytes, we want to see their ascii representation
# instead of their numeric values (#5260)
# using a slice gives us the ascii representation:
# >>> s = b'foo'
# >>> s[0]
# 102
# >>> s[0:1]
# b'f'
left_value = left[i : i + 1]
right_value = right[i : i + 1]
else:
left_value = left[i]
right_value = right[i]
explanation += [f"At index {i} diff: {left_value!r} != {right_value!r}"]
break
if comparing_bytes:
# when comparing bytes, it doesn't help to show the "sides contain one or more
# items" longer explanation, so skip it
return explanation
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 += [f"{dir_with_more} contains one more item: {extra}"]
else:
explanation += [
"%s contains %d more items, first extra item: %s"
% (dir_with_more, len_diff, extra)
]
return explanation
def _compare_eq_set(
left: AbstractSet[Any], right: AbstractSet[Any], verbose: int = 0
) -> List[str]:
explanation = []
diff_left = left - right
diff_right = right - left
if diff_left:
explanation.append("Extra items in the left set:")
for item in diff_left:
explanation.append(saferepr(item))
if diff_right:
explanation.append("Extra items in the right set:")
for item in diff_right:
explanation.append(saferepr(item))
return explanation
def _compare_eq_dict(
left: Mapping[Any, Any], right: Mapping[Any, Any], verbose: int = 0
) -> List[str]:
explanation: List[str] = []
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 += ["Omitting %s identical items, use -vv to show" % len(same)]
elif same:
explanation += ["Common items:"]
explanation += pprint.pformat(same).splitlines()
diff = {k for k in common if left[k] != right[k]}
if diff:
explanation += ["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(
"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(
"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: Any, right: Any, verbose: int) -> List[str]:
if not has_default_eq(left):
return []
if isdatacls(left):
import dataclasses
all_fields = dataclasses.fields(left)
fields_to_check = [info.name for info in all_fields if info.compare]
elif isattrs(left):
all_fields = left.__attrs_attrs__
fields_to_check = [field.name for field in all_fields if getattr(field, "eq")]
elif isnamedtuple(left):
fields_to_check = left._fields
else:
assert False
indent = " "
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 or diff:
explanation += [""]
if same and verbose < 2:
explanation.append("Omitting %s identical items, use -vv to show" % len(same))
elif same:
explanation += ["Matching attributes:"]
explanation += pprint.pformat(same).splitlines()
if diff:
explanation += ["Differing attributes:"]
explanation += pprint.pformat(diff).splitlines()
for field in diff:
field_left = getattr(left, field)
field_right = getattr(right, field)
explanation += [
"",
"Drill down into differing attribute %s:" % field,
("%s%s: %r != %r") % (indent, field, field_left, field_right),
]
explanation += [
indent + line
for line in _compare_eq_any(field_left, field_right, verbose)
]
return explanation
def _notin_text(term: str, text: str, verbose: int = 0) -> List[str]:
index = text.find(term)
head = text[:index]
tail = text[index + len(term) :]
correct_text = head + tail
diff = _diff_text(text, correct_text, verbose)
newdiff = ["%s is contained here:" % saferepr(term, maxsize=42)]
for line in diff:
if line.startswith("Skipping"):
continue
if line.startswith("- "):
continue
if line.startswith("+ "):
newdiff.append(" " + line[2:])
else:
newdiff.append(line)
return newdiff
def running_on_ci() -> bool:
"""Check if we're currently running on a CI system."""
env_vars = ["CI", "BUILD_NUMBER"]
return any(var in os.environ for var in env_vars)