Feature: Mash::UnderscoreKeys Extensions

[arianf]

This extension can be mixed into a Mash to change the default behavior of converting keys to be underscore. After mixing this extension into a Mash, the Mash will convert all string keys to underscore. It can be useful to use with external source hashes, which maybe contain hyphens or CamelCase.

class UnderscoreMash < ::Hashie::Mash
  include Hashie::Extensions::Mash::UnderscoreKeys
end
mash = UnderscoreMash.new
mash.updatedAt = 'Today' #=> 'Today'
mash.updatedAt #=> 'Today'
mash[:updated_at] #=> 'Today'
mash['updated_at'] #=> 'Today'
mash.updated_at #=> 'Today'
mash.to_hash #=> {"updated_at"=>true}

The other benefit is hashes that have hyphens can be accessed with methods

mash = UnderscoreMash.new('created-at': 'tomorrow') #=> {"created_at"=>"tomorrow"}
mash.created_at #=> 'tomorrow'

[dblock]

Couple of questions ... Should we also extend KeyConversion? Find a more generic implementation that can camelize, underscore, etc., keys?

[dblock]

This seems quite a bit different from, say, https://github.com/rails/rails/blob/04972d9b9ef60796dc8f0917817b5392d61fcf09/activesupport/lib/active_support/inflector/methods.rb#L96, what are the differences?

[arianf]

I guess I went pretty old school and grabbed the version from 3.1 haha
https://github.com/rails/rails/blob/4dacedf983257aef38a8ebedb2d9a9c8fead8238/activesupport/lib/active_support/inflector/methods.rb#L48

I can update it to reflect the new version, I think there are likely performance and edge case improvements.

The one difference to this method that I added was converting spaces to underscores as well.

[dblock]

Are you sure we want a different "underscore" behavior than ActiveSupport? Why?

[arianf]

Hmm, I was thinking this could be slightly different than Rails. The intent here is making method names compatible with the Ruby's method naming conversions. createdAt -> created_at

But I think it could also go a step further, "created at" also does not follow the method naming convention, as a space is an illegal character. So my thought was we could convert them to underscore as well.

Maybe this should be called Hashie::Extensions::Mash::MethodSafeKeys to not cause confusion. What do you think?

But I'm also okay just keeping it exactly the same as rails. Either way works for me, just feel the former is more convenient

[dblock]

What do you think about implementing a generic extension that lets me transform keys whichever way I want (TransformKeys) as a custom behavior, and then deriving it into a bunch of specific behaviors such as a rails-compatible UnderscoreKeys?

[dangerpr-bot]

	1 Error
🚫	One of the lines below found in CHANGELOG.md doesn't match the expected format.

## [Unreleased][unreleased]

### Miscellaneous

Generated by 🚫 Danger

[arianf]

Should we also extend KeyConversion? Find a more generic implementation that can camelize, underscore, etc., keys?

@dblock were you thinking of Hashie::Extensions::UnderscoreKeys and Hashie::Extensions::CamelCaseKeys as extensions?

[dblock]

Should we also extend KeyConversion? Find a more generic implementation that can camelize, underscore, etc., keys?

@dblock were you thinking of Hashie::Extensions::UnderscoreKeys and Hashie::Extensions::CamelCaseKeys as extensions?

Yes.

[dblock]

I think this change is good to merge as is. Other improvements like suggested above can be made later. Can you please fix CHANGELOG to make Danger happy?

[dblock]

This is just missing a period.

[dblock]

Nitpick: Can we lowercase today so that it matches the below tomorrow pls.

[dblock]

Looking closer I think ACRONYMS is very controversial. It has nothing to do with underscoring keys, it's a whole other function. Seems like it doesn't belong here. And generally modifying a CONSTANT inside a module is probably not the right way to override anything.

Care to remove for now and let's discuss in a separate PR?

[phortx]

Any plans to finish this? :)

[mculp]

me 2