How to run a code-generator on the top of another code-generator?

Question

Using the source_gen stack to make a code generator, how can I make a generator that generates code that would be the input of another generator (more specifically json_se

Answer 1

It's not possible just with annotation because there maybe two packages that both have the @JsonSerializable annotation

There are two situtations :

• You know what other generators should run after your generator.

  • https://stackoverflow.com/a/59605830/6877472 is one of the solutions
  • you can use the other generator's code in your own generator and call their generator's.generate function. example code:

class Example extends Generator {
    @override
    String generate(LibraryReader library, BuildStep buildStep) {
      return JsonSerializable().generate('''
          @JsonSerializable(nullable: false)
          class Person {
            final String firstName;
            final String lastName;
            final DateTime dateOfBirth;
            Person({this.firstName, this.lastName, this.dateOfBirth});
            factory Person.fromJson(Map json) => _PersonFromJson(json);
            Map toJson() => _PersonToJson(this);
          }
        ''');
     }

}

• You don't know what other generators should run after your generator.

Unfortunately currently there is no way to tell the source_gen that your generator may produce a code that needs code generation.

I created an issue here https://github.com/dart-lang/source_gen/issues/442 if you want to subscribe