There are few options how to handle this:

• use `resolverValidationOptions.allowResolversNotInSchema` [1] option here [2]
  • it is one line change in data-sync-server
  • it will keep resolvers in db
• remove leftover resolvers from db in data-sync-server when schema changes
• remove leftover resolvers from db in data-sync-ui, once user saves schema

IMO we should delete leftover resolvers from DB and we should notify user about that if that happens (similarly to how we notify user about deletion of resolvers when deleting data source). So I would say we should remove them with data-sync-ui.

Wojciech Trocki would this be right approach?

[1] https://www.apollographql.com/docs/graphql-tools/generate-schema.html#makeExecutableSchema
[2] https://github.com/aerogear/data-sync-server/blob/master/server/lib/schemaParser.js#L13