bug#46351: 28.0.50; Add convenient way to bypass Eshell's own pipelining

[Sean Whitton]

Hello,

On Thu 20 Jan 2022 at 07:41PM +01, Michael Albinus wrote:

> However, if I understand your test cases, they check that the eshell
> commands are manipulated as you expect. The tests do not run the
> resulting command itself, checking the output. This is a little bit
> unfortune, because you could check that the output is indeed what you
> expect. And perhaps you could find some constellations, where the output
> is different when using either *| or |. This would be another proof that
> your changes work.
>
> And this would also give some guidance, where your approach has
> limitations (if exist). Showing also *failing* tests in one way or
> another is always a benefit. Your tests use only should, there is no
> should-not or should-error.
>
> Another benefit of testing working examples and their output is
> documentation. I always have trouble to understand documentation of
> unknown (to me) features in Emacs. I have the attitude to run the
> respective ert tests, and to study how the feature is applied by its
> developer. Often, it is more instructive than documentation, and I can
> steal the code.

I hadn't thought of tests as specifically useful alongside
documentation.  Thank you.  I will include some additional tests of this
nature in my next revision.

-- 
Sean Whitton