Macro annotation information in yaml files next steps

[davidmorgan]

Per #3728 there is a plan to pull macro data--information about which annotations trigger macro execution, and exactly what they trigger--into yaml files and from there into package_config.json so it's available to all the tools.

That discussion hasn't quite finished yet but it does seem we know enough to start looking at how to build it.

@jakemac53 suggested talking to the pub team :)

@jonasfj who would be a good person to talk to, please?

Assuming the feature makes sense and gets approved :) I guess we'll need some specification for the new yaml, then new code so that the information ends up in package_config.json and more new code to usefully read it from there.

I mention now because I'll be in AAR next Mon + Tue (morning only) in case that gives an opportunity to discuss in person.

Thanks.

[bwilkerson]

We will likely want to extend some IDE functionality to better support this (after the format is stable). For example, we currently support code completion in both the pubspec.yaml and analysis_options.yaml files, so it seems reasonable to support it in this file as well. We also have error checking for both existing files, so it might (depending on the data in the file) make sense to error check this file as well (things like valid file paths, for example).

[davidmorgan]

Thanks Brian. The details aren't finalized yet as to whether there will be any new files, or just pack everything into existing pubspec.yaml and package_config.json. Either way, yes, there are likely to be IDE considerations. Thanks!

[davidmorgan]

@jonasfj and I chatted about this one.

Jonas has an old proposal for adding a key+value config to pubspec.yaml+package_config.json that seems like a surprisingly good fit.

Jonas, could you please share that doc w/Jake and I? I can't find it :) ...