Function _enter_context

Lib/unittest/case.py:106–127

(cm, addcleanup)

def _enter_context(cm, addcleanup):
    # We look up the special methods on the type to match the with
    # statement.
    cls = type(cm)
    try:
        enter = cls.__enter__
        exit = cls.__exit__
    except AttributeError:
        msg = (f"'{cls.__module__}.{cls.__qualname__}' object does "
               "not support the context manager protocol")
        try:
            cls.__aenter__
            cls.__aexit__
        except AttributeError:
            pass
        else:
            msg += (" but it supports the asynchronous context manager "
                    "protocol. Did you mean to use enterAsyncContext()?")
        raise TypeError(msg) from None
    result = enter(cm)
    addcleanup(exit, cm, None, None, None)
    return result


_module_cleanups = []