Improve types around repr_failure()

Author: bluetech

src/_pytest/_code/code.py

@@ -47,7 +47,7 @@
     from typing_extensions import Literal
     from weakref import ReferenceType
 
-    _TracebackStyle = Literal["long", "short", "line", "no", "native", "value"]
+    _TracebackStyle = Literal["long", "short", "line", "no", "native", "value", "auto"]
 
 
 class Code:

src/_pytest/doctest.py

@@ -300,7 +300,10 @@ def _disable_output_capturing_for_darwin(self) -> None:
             sys.stdout.write(out)
             sys.stderr.write(err)
 
-    def repr_failure(self, excinfo):
+    # TODO: Type ignored -- breaks Liskov Substitution.
+    def repr_failure(  # type: ignore[override] # noqa: F821
+        self, excinfo: ExceptionInfo[BaseException],
+    ) -> Union[str, TerminalRepr]:
         import doctest
 
         failures = (

src/_pytest/nodes.py

@@ -17,9 +17,8 @@
 
 import _pytest._code
 from _pytest._code import getfslineno
-from _pytest._code.code import ExceptionChainRepr
 from _pytest._code.code import ExceptionInfo
-from _pytest._code.code import ReprExceptionInfo
+from _pytest._code.code import TerminalRepr
 from _pytest.compat import cached_property
 from _pytest.compat import overload
 from _pytest.compat import TYPE_CHECKING
@@ -29,7 +28,6 @@
 from _pytest.deprecated import NODE_USE_FROM_PARENT
 from _pytest.fixtures import FixtureDef
 from _pytest.fixtures import FixtureLookupError
-from _pytest.fixtures import FixtureLookupErrorRepr
 from _pytest.mark.structures import Mark
 from _pytest.mark.structures import MarkDecorator
 from _pytest.mark.structures import NodeKeywords
@@ -43,6 +41,7 @@
     # Imported here due to circular import.
     from _pytest.main import Session
     from _pytest.warning_types import PytestWarning
+    from _pytest._code.code import _TracebackStyle
 
 
 SEP = "/"
@@ -355,8 +354,10 @@ def _prunetraceback(self, excinfo):
         pass
 
     def _repr_failure_py(
-        self, excinfo: ExceptionInfo[BaseException], style=None,
-    ) -> Union[str, ReprExceptionInfo, ExceptionChainRepr, FixtureLookupErrorRepr]:
+        self,
+        excinfo: ExceptionInfo[BaseException],
+        style: "Optional[_TracebackStyle]" = None,
+    ) -> TerminalRepr:
         if isinstance(excinfo.value, ConftestImportFailure):
             excinfo = ExceptionInfo(excinfo.value.excinfo)
         if isinstance(excinfo.value, fail.Exception):
@@ -406,8 +407,10 @@ def _repr_failure_py(
         )
 
     def repr_failure(
-        self, excinfo, style=None
-    ) -> Union[str, ReprExceptionInfo, ExceptionChainRepr, FixtureLookupErrorRepr]:
+        self,
+        excinfo: ExceptionInfo[BaseException],
+        style: "Optional[_TracebackStyle]" = None,
+    ) -> Union[str, TerminalRepr]:
         """
         Return a representation of a collection or test failure.
 
@@ -453,13 +456,16 @@ def collect(self) -> Iterable[Union["Item", "Collector"]]:
         """
         raise NotImplementedError("abstract")
 
-    def repr_failure(self, excinfo):
+    # TODO: This omits the style= parameter which breaks Liskov Substitution.
+    def repr_failure(  # type: ignore[override] # noqa: F821
+        self, excinfo: ExceptionInfo[BaseException]
+    ) -> Union[str, TerminalRepr]:
         """
         Return a representation of a collection failure.
 
         :param excinfo: Exception information for the failure.
         """
-        if excinfo.errisinstance(self.CollectError) and not self.config.getoption(
+        if isinstance(excinfo.value, self.CollectError) and not self.config.getoption(
             "fulltrace", False
         ):
             exc = excinfo.value

src/_pytest/python.py

@@ -60,6 +60,7 @@
 from _pytest.outcomes import fail
 from _pytest.outcomes import skip
 from _pytest.pathlib import parts
+from _pytest.reports import TerminalRepr
 from _pytest.warning_types import PytestCollectionWarning
 from _pytest.warning_types import PytestUnhandledCoroutineWarning
 
@@ -1591,7 +1592,10 @@ def _prunetraceback(self, excinfo: ExceptionInfo) -> None:
                     for entry in excinfo.traceback[1:-1]:
                         entry.set_repr_style("short")
 
-    def repr_failure(self, excinfo, outerr=None):
+    # TODO: Type ignored -- breaks Liskov Substitution.
+    def repr_failure(  # type: ignore[override] # noqa: F821
+        self, excinfo: ExceptionInfo[BaseException], outerr: None = None
+    ) -> Union[str, TerminalRepr]:
         assert outerr is None, "XXX outerr usage is deprecated"
         style = self.config.getoption("tbstyle", "auto")
         if style == "auto":

src/_pytest/runner.py

@@ -2,6 +2,7 @@
 import bdb
 import os
 import sys
+from typing import Any
 from typing import Callable
 from typing import cast
 from typing import Dict
@@ -256,7 +257,7 @@ class CallInfo(Generic[_T]):
     """
 
     _result = attr.ib(type="Optional[_T]")
-    excinfo = attr.ib(type=Optional[ExceptionInfo])
+    excinfo = attr.ib(type=Optional[ExceptionInfo[BaseException]])
     start = attr.ib(type=float)
     stop = attr.ib(type=float)
     duration = attr.ib(type=float)
@@ -313,7 +314,8 @@ def pytest_runtest_makereport(item: Item, call: CallInfo[None]) -> TestReport:
 
 def pytest_make_collect_report(collector: Collector) -> CollectReport:
     call = CallInfo.from_call(lambda: list(collector.collect()), "collect")
-    longrepr = None
+    # TODO: Better typing for longrepr.
+    longrepr = None  # type: Optional[Any]
     if not call.excinfo:
         outcome = "passed"  # type: Literal["passed", "skipped", "failed"]
     else:

src/_pytest/skipping.py

@@ -148,7 +148,8 @@ def pytest_runtest_makereport(item: Item, call: CallInfo[None]):
 
     elif item.config.option.runxfail:
         pass  # don't interfere
-    elif call.excinfo and call.excinfo.errisinstance(xfail.Exception):
+    elif call.excinfo and isinstance(call.excinfo.value, xfail.Exception):
+        assert call.excinfo.value.msg is not None
         rep.wasxfail = "reason: " + call.excinfo.value.msg
         rep.outcome = "skipped"
     elif evalxfail and not rep.skipped and evalxfail.wasvalid() and evalxfail.istrue():