New module for input verification proposal

[amaloney]

There is replicated code amongst a couple different plots. As an example, when credible intervals kinds are checked, we duplicate the same code in two different places.

https://github.com/arviz-devs/arviz-plots/blob/a1e32a5dc565ec4ffad317ee106cf9f1f3592bda/src/arviz_plots/plots/forestplot.py#L168-L169

https://github.com/arviz-devs/arviz-plots/blob/a1e32a5dc565ec4ffad317ee106cf9f1f3592bda/src/arviz_plots/plots/distplot.py#L151-L152

I'd like to propose a new module in plots called verify, where we can add methods like the below example.

def credible_interval_kind(ci_kind: str | None) -> str:
    if ci_kind not in ("hdi", "eti", None):
        raise ValueError("`ci_kind` must be either 'hdi' or 'eti'.")
    if ci_kind is None:
        ci_kind = rcParams["stats.ci_kind"]
    return ci_kind

This way in the plot code we can do the following.

from arviz_plots.plots import verify

def plot_forest(...):
    ...
    ci_kind = verify.credible_interval_kind(ci_kind=ci_kind)
    ...

We can extend this to other checks, e.g. sample_dims. We could also extend it further and have all "verification" checks for a plotting method wrapped up into a single method like verify.forestplot_args() or the equivalent. The goal would be to move the if statements at the beginning of each of the *plot.py methods to their own module where we could even add checks for plot_kwargs or pc_kwargs if needed in the future.

@OriolAbril if this sounds reasonable, you can assign the task to me.

[OriolAbril]

That would be great, thanks! It would also make https://github.com/arviz-devs/arviz-plots/issues/66#issuecomment-2212494391 quite straightforward to implement

[amaloney]

Great, I cannot assign myself the ticket. I will if you are okay giving me pull access to the repo. Otherwise I can clone etc...

[OriolAbril]

You should have write permission to this repo as ArviZ core contributor. Probably means I messednup when setting it up. I'll check and fix it later today

[OriolAbril]

Should be fixed now