Rename a field to resolve data in GraphQL [duplicate] - node.js

Question

When defining the userType in the following GraphQL schema on the server, how can I rename the "name" field to "firstname" while still referring to the "name" field in fakeDatabase?
The following code snippet has been copied from the official GraphQL docs
var express = require('express');
var graphqlHTTP = require('express-graphql');
var graphql = require('graphql');
// Maps id to User object
var fakeDatabase = {
'a': {
id: 'a',
name: 'alice',
},
'b': {
id: 'b',
name: 'bob',
},
};
// Define the User type
var userType = new graphql.GraphQLObjectType({
name: 'User',
fields: {
id: { type: graphql.GraphQLString },
// How can I change the name of this field to "firstname" while still referencing "name" in our database?
name: { type: graphql.GraphQLString },
}
});
// Define the Query type
var queryType = new graphql.GraphQLObjectType({
name: 'Query',
fields: {
user: {
type: userType,
// `args` describes the arguments that the `user` query accepts
args: {
id: { type: graphql.GraphQLString }
},
resolve: function (_, {id}) {
return fakeDatabase[id];
}
}
}
});
var schema = new graphql.GraphQLSchema({query: queryType});
var app = express();
app.use('/graphql', graphqlHTTP({
schema: schema,
graphiql: true,
}));
app.listen(4000);
console.log('Running a GraphQL API server at localhost:4000/graphql');

Answer 1

Resolvers can be used for any type, not just Query and Mutation. That means you can easily do something like this:
const userType = new graphql.GraphQLObjectType({
name: 'User',
fields: {
id: {
type: graphql.GraphQLString,
},
firstName: {
type: graphql.GraphQLString,
resolve: (user, args, ctx) => user.name
},
}
})
The resolver function specifies, given the parent value, arguments for that field and the context, what a field for any instance of a type will resolve to. It could even always return the same static value each time.

Answer 2

There's also a library graphql-tools that let you transform your schema, we use that on our schema stitching service.
const { RenameTypes, transformSchema } = require("graphql-tools");
/*
* Schema transformations:
* Types:
* <> Task -> GetTask
*/
const transformMySchema = schema => {
return transformSchema(schema, [
new RenameTypes(function(name) {
return name == "Task" ? "GetTask" : name;
}),
]);
};
Read more : https://github.com/apollographql/graphql-tools/blob/513108b1a6928730e347191527cba07d68aadb74/docs/source/schema-transforms.md#modifying-types
Does this answer the question ?