SPEC: Allow periods in shard name

[straight-shoota]

This is a proposal to allow period (.) in the name of a spec.

The main reason to allow this is because its already in use (since there is no strict enforcement anyways). There are a number of shards ending with .cr, for example https://github.com/TPei/progress_bar.cr, https://github.com/krthr/haye.cr, https://github.com/imdrasil/hermes.cr
This is somewhat of an attempt to "legalize" those names.

I'm not aware of any specific reason for prohibiting this character. There might be some source of confusion with respect to file extensions. But since shard names are typically used as directories, I don't see any real issues there.
The general idea is to keep the allowed character limited, but basic special characters should be allowed (dashes and underscores are already allowed).

/cc crystal-lang/crystal#8737

[ysbaddaden]

I don't see any benefit for allowing dots in shard names. I see confusion, especially when the shard name ends with .cr that is similar to having crystal appear in your shard name, which we already recommend against.

[Sija]

@straight-shoota IMO the repo name and shard name are two different things - there's nothing wrong in having a . within the repo name but in the shard name...?

[straight-shoota]

@Sija It's not just the repo names. The referenced repos define the shard name ending with .cr in their shard.yml.

[Sija]

IMO that's a bit too much. Imagine require "foo.cr"...

[straight-shoota]

Thanks for your input. There seems to be no support for periods in shard names.

We could consider taking measures to prohibit them altogether. That would however break existing shards with periods in their name and shards using them as dependencies.
On shardbox.org there are six shards with periods, all ending in .cr:

• https://github.com/TPei/progress_bar.cr
• https://github.com/libpixel/libpixel.cr
• https://github.com/krthr/haye.cr
• https://github.com/imdrasil/hermes.cr
• https://github.com/krthr/pope.cr
• https://github.com/jaredsmithse/ynab.cr

None of them is a dependency of any shard known on shardbox.org. So at least it wouldn't have a big impact if those ceased to work.

I'd definitely try to avoid getting new shards with invalid names. I'll update crystal init to properly validate the name. shards init already sanitizes the folder name.

[straight-shoota]

shards validate would also notify about invalid shard name (#29).

Also should we maybe issue warnings when such a shard is installed, similar to what #341 added for mismatching tag and SPEC version?

[straight-shoota]

Closing. Periods in shard names should not be support.
Warnings can be added when a validation command is introduced.