Function test_flatten_subgroups

testing/python/raises_group.py:152–276

()

def test_flatten_subgroups() -> None:
    # loose semantics, as with expect*
    with RaisesGroup(ValueError, flatten_subgroups=True):
        raise ExceptionGroup("", (ExceptionGroup("", (ValueError(),)),))

    with RaisesGroup(ValueError, TypeError, flatten_subgroups=True):
        raise ExceptionGroup("", (ExceptionGroup("", (ValueError(), TypeError())),))
    with RaisesGroup(ValueError, TypeError, flatten_subgroups=True):
        raise ExceptionGroup("", [ExceptionGroup("", [ValueError()]), TypeError()])

    # mixed loose is possible if you want it to be at least N deep
    with RaisesGroup(RaisesGroup(ValueError, flatten_subgroups=True)):
        raise ExceptionGroup("", (ExceptionGroup("", (ValueError(),)),))
    with RaisesGroup(RaisesGroup(ValueError, flatten_subgroups=True)):
        raise ExceptionGroup(
            "",
            (ExceptionGroup("", (ExceptionGroup("", (ValueError(),)),)),),
        )

    # but not the other way around
    with pytest.raises(
        ValueError,
        match=r"^You cannot specify a nested structure inside a RaisesGroup with",
    ):
        RaisesGroup(RaisesGroup(ValueError), flatten_subgroups=True)  # type: ignore[call-overload]

    # flatten_subgroups is not sufficient to catch fully unwrapped
    with (
        fails_raises_group(
            "`ValueError()` is not an exception group, but would match with `allow_unwrapped=True`"
        ),
        RaisesGroup(ValueError, flatten_subgroups=True),
    ):
        raise ValueError
    with (
        fails_raises_group(
            "RaisesGroup(ValueError, flatten_subgroups=True): `ValueError()` is not an exception group, but would match with `allow_unwrapped=True`"
        ),
        RaisesGroup(RaisesGroup(ValueError, flatten_subgroups=True)),
    ):
        raise ExceptionGroup("", (ValueError(),))

    # helpful suggestion if flatten_subgroups would make it pass
    with (
        fails_raises_group(
            "Raised exception group did not match: \n"
            "The following expected exceptions did not find a match:\n"
            "  ValueError\n"
            "  TypeError\n"
            "The following raised exceptions did not find a match\n"
            "  ExceptionGroup('', [ValueError(), TypeError()]):\n"
            "    Unexpected nested `ExceptionGroup()`, expected `ValueError`\n"
            "    Unexpected nested `ExceptionGroup()`, expected `TypeError`\n"
            "Did you mean to use `flatten_subgroups=True`?",
            add_prefix=False,
        ),
        RaisesGroup(ValueError, TypeError),
    ):