GraphQL Schema: Nexus

The back-and-forth between the schema declaration and resolvers is something I always found laborious when writing GraphQL APIs, and the fact that it is not DRY makes it prone to typos. That's why I now prefer using code-first approach with Nexus, which can also generate TypeScript types to make the whole experience much more pleasant.

Might change soon?

Possibly

Setup#

Yarn
NPM

yarn add nexus

src/lib/api/graphql/schema.ts

import { join } from 'path'

import { makeSchema } from 'nexus'

import * as types from './types'

const schema = makeSchema({
  types,
  outputs: process.env.TS_NODE_DEV
    ? {
        typegen: join(__dirname, '../../../../node_modules/@types/nexus-typegen/index.d.ts'),
        schema: join(__dirname, 'schema.graphql'),
      }
    : {},
})

export default schema

The schema is defined in files like those:

src/lib/api/graphql/types/index.ts

export * from './scalars'
export * from './user'

src/lib/api/graphql/types/scalars.ts

import { VoidResolver } from 'graphql-scalars'
import { asNexusMethod } from 'nexus'

export const VoidScalar = asNexusMethod(VoidResolver, 'void')

src/lib/api/graphql/types/user.ts

import { objectType, extendType } from 'nexus'

export const User = objectType({
  name: 'User',
  definition: t => {
    t.string('name')
  },
})

export const UserQueries = extendType({
  type: 'Query',
  definition: t => {
    t.nonNull.list.field('users', {
      type: 'User',
      resolve: () => [{ name: 'Foo' }],
    })
  },
})

Nexus cannot seem to be authorized to generate the schema and TypeScript types while running on a Vercel serverless function (EROFS: read-only file system), so we need to run an NPM script manually after making schema changes:

  "nexus-schema": "ts-node --transpile-only src/lib/api/graphql/schema.ts"

Prisma Plugin for Nexus#

TODO: nexus-plugin-prisma

Alternatives#

I have not tried TypeGraphQL yet, but it seems like it would integrate well with TypeORM. In terms of code style, I do have a bit of a preference for plain functions over classes and decorators, but that's not a deal-breaker at all. Since Nexus is made by Prisma, and has a plugin for Prisma, it seems like a natural choice to either pick Prisma + Nexus, or TypeORM + TypeGraphQL.