CLI tool codgen command: How to apply recursive derives and attributes?

[tadeohepperle]

Alex raised this question here and after the PR is merged, we need to decide how to implement recursive derives and attributes in the CLI tool.

Right now, you specify derives and attributes like this:

subxt codegen --derive-for-type my_module::my_type=serde::Serialize --attributes-for-type my_module::my_type=#[allow(clippy::all)]

There are these options in my opinion (in order of my preference):

• A: Add new arguments --derive-for-type-recursive and --attributes-for-type-recursive.
• B: Make all derives recursive by default: This would make sense in most cases, but maybe not in all.
• C: Introduce a new input format per derive, e.g. subxt codegen --derive-for-type my_module::my_type=serde::Serialize/recursive so we just adjust the derive_for_type_parser function to check for this flag. This requires some weird syntax though, that the user has to know about.
• D: Have no recursive derives in the CLI. People need to specify the derives manually (status quo)

I think A would be best, what do you guys think? @niklasad1 @lexnv @jsdw

[jsdw]

I'd be up for A or C myself (A is fine for now, but runs into a future limitation if we ever add more options to derives other than "recursive", and C would be more tricky because if we went that route I'd want a general approach to passing arbitrary options to derives that also wasn't syntactically hideous, possible eg being able to have comma separated options after eg my_module::my_type=serde::Serialize,recursive,foo=123)