Generate action wrappers code

[krzema12]

There should be a piece of logic that, given basic info about the action, generates Kotlin code.

[jmfayard]

I can work on that if you want @krzema12
I have experience working with https://github.com/square/kotlinpoet

[krzema12]

@jmfayard That would be really cool, let's try that! I thought about kotlinpoet, but then I figured it will be simpler to generate the whole code by hand because I don't have experience with kotlinpoet. However, I'm open to checking how kotlinpoet will work for us.

So far I don't have much: https://github.com/krzema12/github-actions-kotlin-dsl/commits/generator .
Quickly describing my idea and plan:

• an independent Gradle module that handles wrappers code generation. Input for a single wrapper: actions's owner, name and version. Output: wrapper's code and target path
• have a central place with a list of wrappers that should be generated
• each wrapper should be customizable in terms of e.g. how a certain input should be modeled. Default is a string, but one could use various modes like "integer with special value" or "enumeration with custom value"
• generating the wrappers on demand, not during building the library. In the future, we can thought about making it more intelligent, e.g. (re)generating only these that need to be (re)generated
• best if generated code was kept in another source set, to distinguish it from the manually written code
• prior to generation, remove all generated code so that no leftover from previous generations is left
• have solid tests for different edge cases

I propose to implement and merge it often and in small pieces, so that if our ideas diverge, we can quickly sync and no large amount of work could be wasted in case of change of approach.

[jmfayard]

I have a MVP here #75

[krzema12]

Nice milestone: all wrappers are now generated, there're no hand-crafted ones. What I plan to do still in this task:

• in PRs, regenerate all wrappers so that adding a new one is as easy as adding a line to WrappersToGenerate
• add a wrapper for actions/setup-node@v2 that @jmfayard added in PR Generate a Kotlin wrapper with Kotlin Poet #75

[jmfayard]

Nice!