openFortIO swallows all exceptions

[eivindjahren]

The following will not raise a ValueError as openFortIO swallows it.

    with openFortIO(str(filepath), fmt_file=False) as f:
        raise ValueError()

This is very surprising behavior and should be changed for version 7.

Code here: https://github.com/equinor/resdata/blob/main/python/resdata/resfile/fortio.py#L38-L63

[eivindjahren]

Problem is the implementation of

class FortIOContextManager:
    def __init__(self, fortio):
        self.__fortio = fortio

    def __enter__(self):
        return self.__fortio

    def __exit__(self, exc_type, exc_val, exc_tb):
        self.__fortio.close()
        return exc_type is not None

What should happen is that close is called on __exit__ only, however, exc_type & exc_val, exc_tb is mostly ignored here which then ends up with swallowing the exception. By using contextlib.contextmanager to ensure that close is called on self.__fortio instead, then the exception should be correctly handled.