test_catch_py311.py

import sys

import pytest

from exceptiongroup import ExceptionGroup


def test_catch_ungrouped():
    value_type_errors = []
    zero_division_errors = []
    for exc in [ValueError("foo"), TypeError("bar"), ZeroDivisionError()]:
        try:
            raise exc
        except* (ValueError, TypeError) as e:
            value_type_errors.append(e)
        except* ZeroDivisionError as e:
            zero_division_errors.append(e)

    assert len(value_type_errors) == 2

    assert isinstance(value_type_errors[0], ExceptionGroup)
    assert len(value_type_errors[0].exceptions) == 1
    assert isinstance(value_type_errors[0].exceptions[0], ValueError)

    assert isinstance(value_type_errors[1], ExceptionGroup)
    assert len(value_type_errors[1].exceptions) == 1
    assert isinstance(value_type_errors[1].exceptions[0], TypeError)

    assert len(zero_division_errors) == 1
    assert isinstance(zero_division_errors[0], ExceptionGroup)
    assert isinstance(zero_division_errors[0].exceptions[0], ZeroDivisionError)
    assert len(zero_division_errors[0].exceptions) == 1


def test_catch_group():
    value_runtime_errors = []
    zero_division_errors = []
    try:
        raise ExceptionGroup(
            "booboo",
            [
                ValueError("foo"),
                ValueError("bar"),
                RuntimeError("bar"),
                ZeroDivisionError(),
            ],
        )
    except* (ValueError, RuntimeError) as exc:
        value_runtime_errors.append(exc)
    except* ZeroDivisionError as exc:
        zero_division_errors.append(exc)

    assert len(value_runtime_errors) == 1
    assert isinstance(value_runtime_errors[0], ExceptionGroup)
    exceptions = value_runtime_errors[0].exceptions
    assert isinstance(exceptions[0], ValueError)
    assert isinstance(exceptions[1], ValueError)
    assert isinstance(exceptions[2], RuntimeError)

    assert len(zero_division_errors) == 1
    assert isinstance(zero_division_errors[0], ExceptionGroup)
    exceptions = zero_division_errors[0].exceptions
    assert isinstance(exceptions[0], ZeroDivisionError)


def test_catch_nested_group():
    value_runtime_errors = []
    zero_division_errors = []
    try:
        nested_group = ExceptionGroup(
            "nested", [RuntimeError("bar"), ZeroDivisionError()]
        )
        raise ExceptionGroup("booboo", [ValueError("foo"), nested_group])
    except* (ValueError, RuntimeError) as exc:
        value_runtime_errors.append(exc)
    except* ZeroDivisionError as exc:
        zero_division_errors.append(exc)

    assert len(value_runtime_errors) == 1
    exceptions = value_runtime_errors[0].exceptions
    assert isinstance(exceptions[0], ValueError)
    assert isinstance(exceptions[1], ExceptionGroup)
    assert isinstance(exceptions[1].exceptions[0], RuntimeError)

    assert len(zero_division_errors) == 1
    assert isinstance(zero_division_errors[0], ExceptionGroup)
    assert isinstance(zero_division_errors[0].exceptions[0], ExceptionGroup)
    assert isinstance(
        zero_division_errors[0].exceptions[0].exceptions[0], ZeroDivisionError
    )


def test_catch_no_match():
    try:
        try:
            group = ExceptionGroup("booboo", [ZeroDivisionError()])
            raise group
        except* (ValueError, RuntimeError):
            pass
    except ExceptionGroup as exc:
        assert isinstance(exc.exceptions[0], ZeroDivisionError)
        assert exc is not group
    else:
        pytest.fail("Did not raise an ExceptionGroup")


def test_catch_single_no_match():
    try:
        try:
            raise ZeroDivisionError
        except* (ValueError, RuntimeError):
            pass
    except ZeroDivisionError:
        pass
    else:
        pytest.fail("Did not raise an ZeroDivisionError")


def test_catch_full_match():
    try:
        raise ExceptionGroup("booboo", [ValueError()])
    except* (ValueError, RuntimeError):
        pass


@pytest.mark.skipif(
    sys.version_info < (3, 11, 4),
    reason="Behavior was changed in 3.11.4",
)
def test_catch_handler_raises():
    with pytest.raises(RuntimeError, match="new") as exc:
        try:
            excgrp = ExceptionGroup("booboo", [ValueError("bar")])
            raise excgrp
        except* ValueError:
            raise RuntimeError("new")

    context = exc.value.__context__
    assert isinstance(context, ExceptionGroup)
    assert str(context) == "booboo (1 sub-exception)"
    assert len(context.exceptions) == 1
    assert isinstance(context.exceptions[0], ValueError)
    assert exc.value.__cause__ is None


def test_catch_subclass():
    lookup_errors = []
    try:
        raise KeyError("foo")
    except* LookupError as e:
        lookup_errors.append(e)

    assert len(lookup_errors) == 1
    assert isinstance(lookup_errors[0], ExceptionGroup)
    exceptions = lookup_errors[0].exceptions
    assert isinstance(exceptions[0], KeyError)


def test_bare_raise_in_handler():
    """Test that the "middle" ecxeption group gets discarded."""
    with pytest.raises(ExceptionGroup) as excgrp:
        try:
            try:
                first_exc = RuntimeError("first")
                raise first_exc
            except RuntimeError as exc:
                middle_exc = ExceptionGroup(
                    "bad", [ValueError(), ValueError(), TypeError()]
                )
                raise middle_exc from exc
        except* ValueError:
            raise
        except* TypeError:
            pass

    assert excgrp.value is not middle_exc
    assert excgrp.value.__cause__ is first_exc
    assert excgrp.value.__context__ is first_exc


def test_bare_reraise_from_naked_exception():
    with pytest.raises(ExceptionGroup) as excgrp:
        try:
            raise KeyError("foo")
        except* KeyError:
            raise

    assert len(excgrp.value.exceptions) == 1
    assert isinstance(excgrp.value.exceptions[0], KeyError)
    assert str(excgrp.value.exceptions[0]) == "'foo'"