Re: [PATCH v2 13/17] iotests/migration-permissions: use assertRaises() for qemu_io() negative test

[Eric Blake]

On Thu, Mar 24, 2022 at 02:30:14PM -0400, John Snow wrote:
> Modify this test to use assertRaises for its negative testing of
> qemu_io. If the exception raised does not match the one we tell it to
> expect, we get *that* exception unhandled. If we get no exception, we
> get a unittest assertion failure and the provided emsg printed to
> screen.
> 
> If we get the CalledProcessError exception but the output is not what we
> expect, we re-raise the original CalledProcessError.
> 
> Tidy.
> 
> (Note: Yes, you can reference "with" objects after that block ends; it
> just means that ctx.__exit__(...) will have been called on it. It does
> not *actually* go out of scope. unittests expects you to want to inspect
> the Exception object, so they leave it defined post-exit.)

Thanks for adding that paragraph.

> 
> Signed-off-by: John Snow <jsnow@redhat.com>
> Reviewed-by: Eric Blake <eblake@redhat.com>
> Tested-by: Eric Blake <eblake@redhat.com>
> Reviewed-by: Hanna Reitz <hreitz@redhat.com>
> ---

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
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