While `App::error` is what most people will need, `clap_derive` needs to
handle when the site raising the error doesn't have access to the `App`
and needs to defer that to later.
Due to a copy/paste bug, we were reading the `help_heading` for
Subcommands from the enum's attribute and not the variant's attribute.
It doesn't make sense for the outer command's help_heading to control
the subcommands help_heading.
This does raise an interesting question on inheriting / propagating help_heading,
which I originally wrote the tests for. We'd first need to answer
whether it should be built-in to the builder or derive-specific.
In working on converting unwraps to errors, I noticed that we did not
spport `arg_enum` for `Option<Option<_>>` and `Option<Vec<_>>`, so this
addresses that.
My main motivation was to consolidate and make the logic more
consistent, the bug fix just fell out of that work.
This is meant to lower the chance of confusion with cases like #2714 and #1586.
This is not meant to be exhaustive, looked at the mentioned cases in
that issue and pattern matched on other ones mentioning "is present".
When I'm making changes, I frequently have to touch every error
function. This creates a more standard builder API so we can more
easily add or modify fields without having to update every case.
PR #2751 highlighted a problem we have where the variable names we use
could collide with users. Rather than parse out when or not to use
special names, and worry about people keeping that up to date through
refactors, I globally renamed all variables by adding a `__clap_`
prefix, which looks like what serde does to solve this problem.
I audited the result with `cargo expand`. I didn't add any tests
because any tests would be reactionary and would give us a false sense
of protection since any new code could hit this with anything we do.
Our best route for naming is consistency so people are likely to notice
and copy.
Fixes#2934
While in some cases "branches-sharing-code" might catch bugs, it overall encourages a form
of DRY that leads to bad code. In this specific case, it is relying on
the implementation detail of the formatting of each branch being the
same. If the `'` wasn't part of it, I could see it being about a shared
`?` to go with the shared start of the question.
In considering potential work for #2683, I realized we might need a type to carry data for
each of the `multiple_values`. `ArgValue` works both for that and for
possible values, so we need to come up with a better name for one or
both. Changing `ArgValue`s name now would be ideal since its new in
clap3 and by renaming it, we can reduce churn for users.
While thinking about this, I realized I regularly get these mixed
up, so renaming `ArgValue` to `PossibleValue` I think will help clear
things up, regardless of #2683.
2902: Minor cosmetic: Place default/env/… on separate lines for multiline help output r=pksunkara a=jcaesar
Co-authored-by: Julius Michaelis <glitter@liftm.de>
This gives users the basic error template for quick and dirty messages.
In addition to the lack of customization, they are not given anything to help
them with coloring or for programmayic use (info, source).
This is something I've wanted many times for one-off validation that
can't be expressed with clap's validation or it just wasn't worth
the hoops. The more pressing need is for #2255, I need `clap_derive`
to be able to create error messages and `Error::with_description` seemed
too disjoint from the rest of the clap experience that it seemed like
users would immediately create issues about it showing up.
With this available, I've gone ahead and deprecated
`Error::with_description` (added in 58512f2fc), assuming this will be
sufficient for users needs (or they can use IO Errors as a back door).
I did so according to the pattern in #2718 despite us not being fully
resolved on that approach yet.
