This simple utility will help you to collect all static fromJSON methods in one static JsonSerializableCollector class. That's all he does.

This bad code will help you improve your life. I wrote as best as I could. If you know how to write this utility better - write. Criticism is unacceptable. PRs are welcome.

flutter pub run json_serializable_collector %path 
where %path is absolute path to output for generator directory