Is there any plugin to prefix the default types such as Query, Node, Cursor, PageInfo?

[codef0rmerz]

I tried to hook up a postgraphile GQL service into Apollo Federation Gateway using @graphile/federation plugin. This worked as expected. However, when use more than one postgraphile GQL service, I get a schema validation error such as GraphQLSchemaValidationError: There can be only one type named "PageInfo".

Is there a way to prefix those default types so that each postgraphile GQL service will have unique type names for the Apollo Gateway to run smoothly?

[benjie]

Many of these use the builtin inflector which has the default implementation of str => str but you can customise that via https://www.graphile.org/postgraphile/make-add-inflectors-plugin/

those that do not use any inflector I’d welcome a PR to use the builtin inflector for 👍

[codef0rmerz]

Thanks @benjie. My plugin worked just fine except Cursor which I think does not come under builtin. I also tried looking into all the inflectors but could not find it anywhere.

const MyPlugin = makeAddInflectorsPlugin((inflectors) => {
  const { builtin: oldEnumName } = inflectors;

  return {
    builtin(value) {
      if (value == 'Query' || value == 'Node' || value == 'PageInfo') {
        return oldEnumName.call(this, `postgraphile1${value}`);
      } else {
        return value;
      }
    },
  };
}, true);

However, I ran into another issue. When I combine MyPlugin with FederationPlugin, the gateway just refuses to start.

// Federated Postgraphql service
import FederationPlugin from '@graphile/federation';

app.use(
  postgraphile('<db-string-goes-here>', 'public', {
    watchPg: true,
    graphiql: true,
    enhanceGraphiql: true,
    appendPlugins: [FederationPlugin, MyPlugin]
  })
);

// Apollo Gateway
const serviceList = [
  {
    name: 'postgraphile-apollo1',
    url: `http://localhost:5001/graphql`,
  },
  {
    name: 'postgraphile-apollo2',
    url: `http://localhost:5002/graphql`,
  }
];

const app = express();

const gateway = new ApolloGateway({
  serviceList,
  buildService({ url }) {
    return new RemoteGraphQLDataSource({
      url,
      willSendRequest({ request, context }) {
        request.http.headers.set('Authorization', context.Authorization);
      },
    });
  },
});

(async () => {
  const { schema, executor } = await gateway.load();

With MyPlugin alongside FederationPlugin, it yells node:84837) UnhandledPromiseRejectionWarning: Error: Couldn't load service definitions for "postgraphile-apollo1" at http://localhost:5001/graphql: 400: Bad Request at node_modules/@apollo/gateway/src/loadServicesFromRemoteEndpoint.ts:73:15

[codef0rmerz]

@benjie Turns out that I should not rename Query type. The above error has gone after I changed the if-cond to if (value == 'Node' || value == 'PageInfo'). However, Apollo is now throwing schema validation error as expected:

UnhandledPromiseRejectionWarning: Error: A valid schema couldn't be composed. The following composition errors were found:
        Field "Query.query" can only be defined once.
        Field "Query.nodeId" can only be defined once.
        Field "Query.node" can only be defined once.

How else do I rename the root type Query?

[benjie]

Delete those fields: https://www.graphile.org/postgraphile/extending-raw/#removing-things-from-the-schema

[codef0rmerz]

@benjie I managed to rename those fields except node using a following plugin.

const MyPlugin2 = function (builder) {
  builder.hook('GraphQLObjectType:fields', (fields) => {
    if (fields.query) {
      fields.queryPostgraphile1 = fields.query;
      delete fields.query;
    } else if (fields.node) {
      fields.nodePostgraphile1 = fields.node;
      delete fields.node;
    }
    return fields;
  });
};

However, that only renamed node field under SecuritiesEdge and not root Query even after trying all the hooks
How else do I target node() thingy under root Query to rename it?

type Query implements Postgraphile1Node {
  """
  The root query type must be a `Node` to work well with Relay 1 mutations. This just resolves to `query`.
  """
  nodeIdPostgraphile1: ID!

  """Fetches an object given its globally unique `ID`."""
  node(
    """The globally unique `ID`."""
    nodeIdPostgraphile1: ID!
  ): Postgraphile1Node
}
type SecuritiesEdge {
  """A cursor for use in pagination."""
  cursor: Cursor

  """The `Security` at the end of the edge."""
  nodePostgraphile1: Security
}

[benjie]

You have elseif; maybe it should just be a separate if statement because you want to perform both actions?

[codef0rmerz]

@benjie No, that wont work because the following node (looks like an interface to me) is not captured by any hook I tried with. The fields.node only targeted the node field under SecuritiesEdge. That means below node is not a field.

Do you know what it's called?

node(
    """The globally unique `ID`."""
    nodeIdPostgraphile1: ID!
 ): Postgraphile1Node

[benjie]

I think you're mistaken.

const MyPlugin2 = function (builder) {
  builder.hook('GraphQLObjectType:fields', (fields) => {
    if (fields.query) {
      fields.queryPostgraphile1 = fields.query;
      delete fields.query;
    }

    // The `else` here prevented `Query.node` being renamed because `Query.query` exists
    // so only the above block executed, not the block below. Remove the `else`.

    if (fields.node) {
      fields.nodePostgraphile1 = fields.node;
      delete fields.node;
    }
    return fields;
  });
};

[codef0rmerz]

When I tried logging fields.node, I thought the hook runs for each field. My bad 👍

[codef0rmerz]

I feel bad for asking too many questions but things are not working as expected as per the documentation.

Here I'm trying to extend the existing typeDef schema using makeExtendSchemaPlugin plugin but it's not working. Neither there is any error. What am I missing?

const MyPlugin3 = makeExtendSchemaPlugin((build) => {
  return {
    typeDefs: gql`
      extend type Securityinfo @key(fields: "id") {
        id: Int! @external
        securityinfoById: [Security!]!
      }
    `
  };
});

[benjie]

makeExtendSchemaPlugin doesn't currently produce errors; if you try and extend something that doesn't exist then that just doesn't do anything (effectively the extension sets up a hook for when that type is declared; but the type is never declared so the hook never fires).

Are you sure Securityinfo exists within your GraphQL schema, and are you sure the case is right (e.g. it's not SecurityInfo?).

[codef0rmerz]

Thanks @benjie. Figured that out, now grokking graphile/federation plugin to improve my plugins.

[benjie]

[semi-automated message] To keep things manageable I'm going to close this issue as I think it's solved; but if not or you require further help please re-open it.

[codef0rmerz]

@benjie Is it possible to add directive @key(fields: "id") on a type?

For example,

type Security implements Postgraphile1Node @key(fields: "id") {
...
}

I tried the approach mentioned here #745 but that just adding a directive on top of the schema i.e. directive @key(fields: "id") on Security prior to defining Security and hence failing.