[SOLVED] Add custom GraphQL resolvers and types into Prisma/Nexus schema

Add custom GraphQL resolvers and types into Prisma/Nexus schema

Using: TypeScript, Prisma, MySQL, GraphQLServer, ApolloClient, building schema this way:

const schema = makePrismaSchema({
  // Provide all the GraphQL types we've implemented
  types: [Query, Mutation, User, Post],...

And then:

  const server = new GraphQLServer({
    schema,
    context: { prisma }
  });

How to combine that with custom resolvers and types unrelated to the SQL?

(I would like to call some REST endpoint by the GQL as well)

Solution

While nexus was created to be used alongside prisma, it's really just a schema builder. You could easily use it to create a schema without even utilizing Prisma. For example:

export const User = prismaObjectType({
  name: 'User',
  definition(t) {
    t.list.field('comments', {
      type: 'Comment',
      resolve(root, args, ctx) {
        return getComments();
      },
    });
  },
})

export const Comment = prismaObjectType({
  name: 'Comment',
  definition(t) {
    t.string('body');
  },
})

Here getComments can return an array of comment objects, or a Promise that resolves to one. For example, if you're calling some other API, you'll normally return a Promise with the results of the call. As shown above, the resolver exposes the parent value, the field's arguments and a context object -- you can use any of this information in determining how to resolve a particular field.