Method __exit__

src/_pytest/recwarn.py:261–296

(
        self,
        exc_type: Optional[Type[BaseException]],
        exc_val: Optional[BaseException],
        exc_tb: Optional[TracebackType],
    )

        self.match_expr = match_expr

    def __exit__(
        self,
        exc_type: Optional[Type[BaseException]],
        exc_val: Optional[BaseException],
        exc_tb: Optional[TracebackType],
    ) -> None:
        super().__exit__(exc_type, exc_val, exc_tb)

        __tracebackhide__ = True

        # only check if we're not currently handling an exception
        if exc_type is None and exc_val is None and exc_tb is None:
            if self.expected_warning is not None:
                if not any(issubclass(r.category, self.expected_warning) for r in self):
                    __tracebackhide__ = True
                    fail(
                        "DID NOT WARN. No warnings of type {} were emitted. "
                        "The list of emitted warnings is: {}.".format(
                            self.expected_warning, [each.message for each in self]
                        )
                    )
                elif self.match_expr is not None:
                    for r in self:
                        if issubclass(r.category, self.expected_warning):
                            if re.compile(self.match_expr).search(str(r.message)):
                                break
                    else:
                        fail(
                            "DID NOT WARN. No warnings of type {} matching"
                            " ('{}') were emitted. The list of emitted warnings"
                            " is: {}.".format(
                                self.expected_warning,
                                self.match_expr,
                                [each.message for each in self],
                            )
                        )