bug#59317: 29.0.50; Feature idea: suppress `message' output in ert batch test output

[Michael Albinus <michael.albinus@gmx.de>]

Matt Armstrong <matt@rfc20.org> writes:

Hi Matt,

> When ERT runs tests interactively the `message' output is not normally
> visible in the "*ert*" buffer.  In fact ERT arranges for the messages to
> not even appear in the minibuffer as they happen.  They are instead
> available on demand with the
> `ert-results-pop-to-messages-for-test-at-point' command, bound to 'm' in
> "*ert*".
>
> When ERT runs tests in batch mode, messages are printed to the console
> intermixed with ERT's progress messages.
>
> Idea: hide `message' output when running in batch mode, printing them
> only for failed tests.
>
> Rationale: for passing tests the output is not useful.  For failing
> tests it can be useful as a kind of trace, so the writing tests that
> avoid all calls to `message' is not necessarily the best option.

Besides the other arguments already given in this thread, I'd like to
emphasize that messages are useful even in batch mode, for successful
tests. This is the only way to study ert tests in batch mode, for
example on our CI/CD machines hydra and emba.

If messages shall be suppressed, this must be controlled by a user
option. However, I'm not in favor to do it at all.

Best regards, Michael.