Graphql-code-generator: Provide a simple way to override schema type for a given field, prior to codegen step

[jamshally]

Is your feature request related to a problem? Please describe.
My schema has a jsonb scalar fileld type. However, the TypeScript codgen plugin simply resolves this to an any TypeScript type. I am looking for a way to provide a custom override type for that field, so that I can get access the JSon contents of that field in a stongly typed way.

Describe the solution you'd like
I would like to simple mechanism to provide a custom type for a given field, so that the code-generation uses the custom priovided type instead of the original schema provided type

Describe alternatives you've considered

• I have defined an additional client schema with the desired field type, but (logically) get codegen errors saying that the field is already defined
  
  
  
  • I have looked for ways of easily altering the schema prior to the code-gen step, but am struggling to figure it out.
  
  

Additional context
I am using an Hasura API, with typescript and typescript-react-apollo plugins

[dotansimha]

@ahrnee just overriding the field doesn't work?
redeclare it in a .graphql file and add it to your schema:, i think it should override the field type.

[jamshally]

@dotansimha - thanks for your response, but that doesn't seem to work in my case. I get the following error:

  Unable to merge GraphQL type "MyEntity": Field "myjsonbfield" already defined with a different type. 
  Declared as "MyCustomFieldType", but you tried to override with "jsonb"

Some Futher Details:

• Im using the Hasura GraphQL engine, which always results in a "jsonb" scalar for all jsonb field types
• I have a client .graphql where I tried to redeclare the field type

Sidenotes

• I also have a feature-request in with the Hasura Team to custom scalar types to be configured for jsonb fields, but at present this is not possible.
  
  
  
  • This feature request is in support of some graphql-code-generator Hasura plugins I am developing. If there is a graphql-code-generator community page, I'd be glad to add it
  
  

[FranckErnewein]

Same problem here.
We generate types from Datocms GraphQL API.
Most of enums are just Scalars['String'].
We really need to override for some fields and we can not change the source API.
We tried to define a local schema but we have the same Error

Unable to merge GraphQL type "TitleRecord": Field "variant" already defined with a different type. Declared as "Variant", but you tried to override with "String"
        Error: Unable to merge GraphQL type "TitleRecord": Field "variant" already defined with a different type. Declared as "Variant", but you tried to override with "String"

It would be very nice to allow merge if needed

[dotansimha]

I think the best way to do that is to use a custom schema loader, then you can manipulate your schema in any way you wish to. (for example, using graphql-compose to change the schema).

Closing.