123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439440441442443444445446447448449450451452453454455456457458459460461462463464465466467468469470471472473474475476477478479480481482483484485486487488489490491492493494495496497498 |
- """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
- import _pytest._code
- from _pytest import outcomes
- from _pytest._io.saferepr import _pformat_dispatch
- from _pytest._io.saferepr import safeformat
- from _pytest._io.saferepr import saferepr
- 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 assertrepr_compare(config, op: str, left: Any, right: Any) -> Optional[List[str]]:
- """Return specialised explanations for some operators/operands."""
- verbose = config.getoption("verbose")
- if verbose > 1:
- left_repr = safeformat(left)
- right_repr = safeformat(right)
- 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)
- right_repr = saferepr(right, maxsize=maxsize)
- 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)
- elif verbose > 0:
- explanation = _compare_eq_verbose(left, right)
- 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 _compare_eq_verbose(left: Any, right: Any) -> List[str]:
- keepends = True
- left_lines = repr(left).splitlines(keepends)
- right_lines = repr(right).splitlines(keepends)
- explanation: List[str] = []
- explanation += ["+" + line for line in left_lines]
- explanation += ["-" + line for line in right_lines]
- 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 not verbose and not running_on_ci():
- return ["Use -v to get the full 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 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, "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)
|