🏗️ Add KSP artifact

[heytherewill]

Summary

This adds the base artifact and the first Symbol Processor for this project

Relationships

Groundwork for #60

Technical considerations

This PR is just the baseline and the code generation for the actions. I'll create subsequent issues for the State and Pullback generation

Tests

I'm testing both generation and the compiler error.

Review pointers

Please review not only the generated code's behavior, but also the overall architecture and ergonomics of the library, specially when applied to actual code.

Merge permissions

Go for it!

[semanticer]

@heytherewill Nice! KSP and Poet look great together. I didn't expect to understand the code soo easily 😅

There seems to be a bug tho. When I copy SettingsAction and AppAction to Todos sample I get this code generated:

public fun mapAppActionToSettingsAction(appAction: AppAction): SettingsAction? = if(appAction is
    .AppAction.Settings) appAction.settingsAction else null

public fun mapSettingsActionToAppAction(settingsAction: SettingsAction): AppAction.Settings =
    .AppAction.Settings(settingsAction)

There is that extra dot there in front of .AppAction.Settings

It looks like adding a +1 here:

val parentActionTypeName = parentActionClassName.canonicalName.substring(parentActionClassName.packageName.length + 1, parentActionClassName.canonicalName.length)

Solves the issue but idk if it's the most robust solution to the problem.

[heytherewill]

Nice find. My original problem was that just getting the class name would not resolve nested classes properly. Adding the +1 like you suggested would break things for classes without a package. .trim('.') (plus adding a test) was the way to go

[semanticer]

Works great, it handled everything I threw at it. But it's not closing #60 perhaps we should turn #60 into checklist with a bunch of sub issues.

[heytherewill]

Good point! Updated the comment, merge away!