[gql_build] ensure all serializer return types (all types?) are available in generated file, or allow import config about gql

[danielmahon]

adding the missing import MyModel into serializers.gql.dart fixes the issue, but I still haven't dug deep enough into built_value to see why/where it's adding those builder factories, and why it's only doing it for the list item and not the other overrides

[smkhalsa]

@danielmahon built_value generates the serializers.gql.g.dart file based on the contents of your serializers.gql.dart.

I don't actually think this has anything to do with the custom serializer. built_value is building the BuilderFactories because one of your GraphQL operations uses a BuiltList<MyModel>, and BuilderFactories are what tell built_value how to serialize BuiltLists of non-standard types.

The easiest solution would be to just include an import of any type overrides by default. I've created PR #148 which implements this. Can you please confirm that it fixes the issue? NOTE: you will need to include your type_overrides map in the serializer_builder in your build.yaml file.

A more elegant solution that selectively imports the custom types only when they will be used in a BuilderFactory would not be trivial, and I think this solution is probably good enough.

[danielmahon]

@smkhalsa this works, thank you