[BUG] [graphql-schema] Generator not generating correct types for Queries and mutations

Description

The schema generator does not work properly.

I used the following command to generate a graphQL-schema for the petstore:

openapi-generator generate -i petstore.yaml -g graphql-schema

The resulting generated schema is not compiling since the mutations and queries are generated like so

type query {
  # Get user by user name
  # 
  # @param String! username The name that needs to be fetched. Use user1 for testing. 
  # @return [User]
  GetUserByName(username: String!): User

  # Logs user into the system
  # 
  # @param String! username The user name for login
  # @param String! password The password for login in clear text
  # @return [String!]
  LoginUser(username: String!, password: String!): String!

  # Logs out current logged in user session
  # 
  # @return [null]
  LogoutUser(): null

} 

Yet a type has to start with a capital letter. Additionally the problem is that the input types, e. g. User in CreateUser are not declared to be an input and thus cannot be used as a parameter for Queries or Mutations.

openapi-generator version

6.2.1

Generation Details

openapi-generator generate -i petstore.yaml -g graphql-schema

Steps to reproduce

Download the petstore yaml.
Execute the following command: openapi-generator generate -i petstore.yaml -g graphql-schema

Suggestions for fix

This probably means that the Queries and Mutations cannot be split in separate files due to resulting name conflicts.
Additionally the types might need to be generated two times once as type and once as input.

Run the documented openapi-generator command with the petstore YAML and inspect the generated GraphQL schema. Check the query and mutation declarations and how model types are used as inputs. Done means the generated schema compiles, uses valid Query and Mutation types, and declares compatible input types for mutation parameters.