Correctly handle tracebackhide for chained exceptions (#10772)

AUTHORS

@@ -128,6 +128,7 @@ Erik M. Bray
 Evan Kepner
 Fabien Zarifian
 Fabio Zadrozny
+Felix Hofstätter
 Felix Nieuwenhuizen
 Feng Ma
 Florian Bruhin

changelog/1904.bugfix.rst

@@ -0,0 +1 @@
+Correctly handle ``__tracebackhide__`` for chained exceptions.

src/_pytest/_code/code.py

@@ -411,13 +411,13 @@ def filter(
  """
  return Traceback(filter(fn, self), self._excinfo)
 
- def getcrashentry(self) -> TracebackEntry:
+ def getcrashentry(self) -> Optional[TracebackEntry]:
  """Return last non-hidden traceback entry that lead to the exception of a traceback."""
  for i in range(-1, -len(self) - 1, -1):
  entry = self[i]
  if not entry.ishidden():
  return entry
- return self[-1]
+ return None
 
  def recursionindex(self) -> Optional[int]:
  """Return the index of the frame/TracebackEntry where recursion originates if
@@ -602,11 +602,13 @@ def errisinstance(
  """
  return isinstance(self.value, exc)
 
- def _getreprcrash(self) -> "ReprFileLocation":
+ def _getreprcrash(self) -> Optional["ReprFileLocation"]:
  exconly = self.exconly(tryshort=True)
  entry = self.traceback.getcrashentry()
- path, lineno = entry.frame.code.raw.co_filename, entry.lineno
- return ReprFileLocation(path, lineno + 1, exconly)
+ if entry:
+ path, lineno = entry.frame.code.raw.co_filename, entry.lineno
+ return ReprFileLocation(path, lineno + 1, exconly)
+ return None
 
  def getrepr(
  self,
@@ -942,18 +944,23 @@ def repr_excinfo(
  )
  else:
  reprtraceback = self.repr_traceback(excinfo_)
- reprcrash: Optional[ReprFileLocation] = (
- excinfo_._getreprcrash() if self.style != "value" else None
- )
+
+ # will be None if all traceback entries are hidden
+ reprcrash: Optional[ReprFileLocation] = excinfo_._getreprcrash()
+ if reprcrash:
+ if self.style == "value":
+ repr_chain += [(reprtraceback, None, descr)]
+ else:
+ repr_chain += [(reprtraceback, reprcrash, descr)]
  else:
  # Fallback to native repr if the exception doesn't have a traceback:
  # ExceptionInfo objects require a full traceback to work.
  reprtraceback = ReprTracebackNative(
  traceback.format_exception(type(e), e, None)
  )
  reprcrash = None
+ repr_chain += [(reprtraceback, reprcrash, descr)]
 
- repr_chain += [(reprtraceback, reprcrash, descr)]
  if e.__cause__ is not None and self.chain:
  e = e.__cause__
  excinfo_ = (
@@ -1044,7 +1051,7 @@ def toterminal(self, tw: TerminalWriter) -> None:
 @dataclasses.dataclass(eq=False)
 class ReprExceptionInfo(ExceptionRepr):
  reprtraceback: "ReprTraceback"
- reprcrash: "ReprFileLocation"
+ reprcrash: Optional["ReprFileLocation"]
 
  def toterminal(self, tw: TerminalWriter) -> None:
  self.reprtraceback.toterminal(tw)

src/_pytest/reports.py

@@ -347,6 +347,10 @@ def from_item_and_call(cls, item: Item, call: "CallInfo[None]") -> "TestReport":
  elif isinstance(excinfo.value, skip.Exception):
  outcome = "skipped"
  r = excinfo._getreprcrash()
+ if r is None:
+ raise ValueError(
+ "There should always be a traceback entry for skipping a test."
+ )
  if excinfo.value._use_item_location:
  path, line = item.reportinfo()[:2]
  assert line is not None

testing/code/test_excinfo.py

@@ -294,6 +294,7 @@ def f():
  excinfo = pytest.raises(ValueError, f)
  tb = excinfo.traceback
  entry = tb.getcrashentry()
+ assert entry is not None
  co = _pytest._code.Code.from_function(h)
  assert entry.frame.code.path == co.path
  assert entry.lineno == co.firstlineno + 1
@@ -311,10 +312,7 @@ def f():
  excinfo = pytest.raises(ValueError, f)
  tb = excinfo.traceback
  entry = tb.getcrashentry()
- co = _pytest._code.Code.from_function(g)
- assert entry.frame.code.path == co.path
- assert entry.lineno == co.firstlineno + 2
- assert entry.frame.code.name == "g"
+ assert entry is None
 
 
 def test_excinfo_exconly():

testing/test_tracebackhide.py

@@ -0,0 +1,25 @@
+def test_tbh_chained(testdir):
+ """Ensure chained exceptions whose frames contain "__tracebackhide__" are not shown (#1904)."""
+ p = testdir.makepyfile(
+ """
+ import pytest
+
+ def f1():
+ __tracebackhide__ = True
+ try:
+ return f1.meh
+ except AttributeError:
+ pytest.fail("fail")
+
+ @pytest.fixture
+ def fix():
+ f1()
+
+
+ def test(fix):
+ pass
+ """
+ )
+ result = testdir.runpytest(str(p))
+ assert "'function' object has no attribute 'meh'" not in result.stdout.str()
+ assert result.ret == 1