[v1] Weird behaviour when extending createSchemaForApollo's schema

[darkbasic]

Describe the bug

I'm upgrading accounts-js to graphql-modules v1. Accounts-js will use v1 internally, but it still needs to supports users who don't want to make use of graphql-modules in their projects. These users, instead of creating their own graphql module, will simply merge their typedefs/resolvers with those provided by accounts-js.

Basically users who want to use graphql-modules will use something like this:

const myModule = createModule({
  id: 'mine',
  typeDefs,
  resolvers,
});

const accountsSchema = createApplication({
  modules: [
    createAccountsCoreModule({ accountsServer }),
    createAccountsPasswordModule({ accountsPassword }),
    myModule,
  ],
}).createSchemaForApollo();

SchemaDirectiveVisitor.visitSchemaDirectives(accountsSchema, {
  auth: AuthenticatedDirective,
} as any);

const server = new ApolloServer({
  schema: accountsSchema,
  context: ({ req, connection }) => {
    return context({ req, connection }, { accountsServer });
  },
});

while users who don't want to use graphql-modules will use something like this:

const accountsSchema = createApplication({
  modules: [
    createAccountsCoreModule({ accountsServer }),
    createAccountsPasswordModule({ accountsPassword }),
  ],
}).createSchemaForApollo();

const accountsTypeDefs = parse(printSchemaWithDirectives(accountsSchema));
const accountsResolvers = getResolversFromSchema(accountsSchema);

const schema = makeExecutableSchema({
  typeDefs: mergeTypeDefs([typeDefs, accountsTypeDefs]),
  resolvers: mergeResolvers([accountsResolvers as any, resolvers]),
  schemaDirectives: {
    auth: AuthenticatedDirective,
  } as any,
});

const server = new ApolloServer({
  schema,
  context: ({ req, connection }) => {
    return context({ req, connection }, { accountsServer });
  },
});

While the former works flawlessly, the latter shows some weird behaviour.

In this example the user wants to extend the User type provided by accounts-js with additional fields:

extend type User {
  firstName: String!
  lastName: String!
}

If I look at the generated schema in GraphiQL I can see that the type has been extended correctly:

type User {
  firstName: String!
  lastName: String!
  id: ID!
  emails: [EmailRecord!]
  username: String
}

but for some reason it doesn't return those types when I run the authenticate mutation: Cannot return null for non-nullable field User.firstName.
This is weird because in all the top level resolvers this field has been provided but somehow it's missing once it reaches the User resolver:

authenticateResolvers
{
  _id: 60bf23248f4bc1acbcab0de3,
  firstName: 'John',
  lastName: 'Doe',
  services: {
    password: {
      bcrypt: '$2a$10$PgtRhEby4y.JqDYX9z2sReukBAIhLHX6k1Qvp5LimBCdcvhb73Ioi'
    }
  },
  createdAt: 1623139108286,
  updatedAt: 1623139108286,
  emails: [ { address: 'john.does@john.com', verified: false } ],
  id: '60bf23248f4bc1acbcab0de3'
}

LoginResultResolvers
{
  _id: 60bf23248f4bc1acbcab0de3,
  firstName: 'John',
  lastName: 'Doe',
  services: {
    password: {
      bcrypt: '$2a$10$PgtRhEby4y.JqDYX9z2sReukBAIhLHX6k1Qvp5LimBCdcvhb73Ioi'
    }
  },
  createdAt: 1623139108286,
  updatedAt: 1623139108286,
  emails: [ { address: 'john.does@john.com', verified: false } ],
  id: '60bf23248f4bc1acbcab0de3'
}

UserResolvers
[Object: null prototype] {
  id: '60bf23248f4bc1acbcab0de3',
  emails: [
    [Object: null prototype] {
      address: 'john.does@john.com',
      verified: false,
      __typename: 'EmailRecord'
    }
  ],
  __typename: 'User'
}

Everything works flawlessly with the former approach (the user creates its own graphql-module).
I tried without createSchemaForApollo but I've got context.ɵgetModuleContext is not a function.

To Reproduce
Steps to reproduce the behavior:

This is the accounts-js branch with graphql-modules v1: https://github.com/darkbasic/accounts/tree/f40419e14030f887066e34d1d454aa5f23cb931c

git clone https://github.com/darkbasic/accounts.git
git checkout f40419e14030f887066e34d1d454aa5f23cb931c
yarn
yarn setup
yarn compile
# Shell 1
cd examples/graphql-server-typescript
docker-compose up -d
yarn start
# Shell 2
cd examples/react-graphql-typescript
yarn start
# Create a new user (I didn't check if it works with the latter approach, change graphql-server-typescript to the former if it doesn't)
# Try to log in (gets Cannot return null for non-nullable field User.firstName)

Expected behavior

There should be a way to be able to extend the typedefs/resolvers from a project which uses graphql-modules in a project which makes use of apollo-server but not graphql-modules itself. What am I doing wrong?

Environment:

• OS: Fedora Linux 34
• @graphql-modules/1.4.2:
• NodeJS: v14.17.0

[ardatan]

createSchemaForApollo uses wrapSchema. The real schema is wrapped inside that's why you cannot modify it directly.
You can get the typeDefs and resolvers from generated app.

const { typeDefs, resolvers }= createApplication({ ... });

[darkbasic]

I tried, but I get context.ɵgetModuleContext is not a function

[ardatan]

@darkbasic Because you still need the context.
See #1724 (comment)

[darkbasic]

So basically graphql-modules v1 is a no go for libraries who also want to target non graphql-modules users who wish to use Apollo Server: I cannot realistically expect them to manually setup weakmaps :(

[darkbasic]

Would be possible to wrap the schema with createSchemaForApollo after letting the user to merge it with its own schema?

[ardatan]

You can use schemaBuilder to decide how to build schema from typeDefs and resolvers;
https://www.graphql-modules.com/docs/api#applicationconfig