Re: [RFC][PATCH] Add zrestart()

[Marlon Richert <marlon.richert@xxxxxxxxx>]

On Mon, Apr 26, 2021 at 10:29 PM Daniel Shahaf <d.s@xxxxxxxxxxxxxxxxxx> wrote:
> > > > +  local err="$(zsh --interactive --monitor --zle -c '' 2>&1 > /dev/null)"
> > >
> > > Also, I think it's quite a stretch to describe this line as "_tests_
> > > whether the shell is able to restart".
> >
>
> Care to comment about the part of my answer before the "Also", which you
> had snipped?

Sure:

On Mon, Apr 26, 2021 at 6:22 AM Daniel Shahaf <d.s@xxxxxxxxxxxxxxxxxx> wrote:
> > +  local err="$(zsh --interactive --monitor --zle -c '' 2>&1 > /dev/null)"
>
> This doesn't necessarily restart the _same_ zsh, if there's more than
> one installed.

I think your observation is correct and I was planning to fix it in
the next version of my patch. :)

When I don't reply to a point you make, it means that I either agree
or think it's not worth arguing about, and I've put it on my TODO list
for the next version of my patch. I was trying to be brief and not
post a bunch of agrees/will-dos or quote unnecessarily. But if it's
prefered that I do respond to every point I agree with and/or quote
each part of every email I reply to, just let me know. :)


> > I originally had `zsh -fn <all the dotfiles>`, along the lines of what
> > was suggested earlier, but that test can fail on a valid dotfile that
> > uses dynamically named dirs.
>
> A minimal example of this would not be out of place.

% zsh_directory_name() { [[ $2 == home ]] && reply=($HOME) }
% cd ~[home]; print $?
0
% print 'zsh_directory_name() { [[ $2 == home ]] && reply=($HOME) }
cd ~[home]' > tmp
% zsh -fn tmp
tmp:2: no directory expansion: ~[home]
%


> > Plus, if any dotfile sources other files,
> > those files aren't checked this way at all. The approach above is the
> > only one I've found so far that appears to be completely reliable in
> > determining whether the shell can start up successfully.
> >
> > > This line executes a whole bunch of code you have no control over.
> >
> > It is, however, exactly the code we want to test here.
>
> I'm aware.  However, you aren't "testing" it, you are *running* it.
>
> First, that means the docs are wrong.
>
> Second, that code might do things that are inappropriate for the use-case
> of "testing" the startup code.

When you execute `make check`, does it not _run_ the code? How else
are you going to test it? :)


> Or, in other words: the trick is to throw the bathwater out and
> keep the baby.  Keeping *both* the baby and the bathwater isn't an
> ideal solution.

What exactly here is the "bathwater"? Would it help to mock out
certain features in the subshell that you wouldn't want to actually
run in this test? Would it help to invoke the subshell with -o
RESTRICTED?