GraphQL

GraphQL is a query language for APIs. Saruni utilizes spec-compliant GraphQL servers from Apollo to build production-ready, self-documenting GraphQL APIs.

Apollo is deployed to an AWS Lambda function as a stand-alone GraphQL server in production, but uses the popular Express Node.js application framework as a drop-in replacement behind the scenes to power local development.

Schema

Every GraphQL server uses a schema to define the structure of data that clients can query. You can learn more about schema syntax here.

We can update schemas in Saruni applications at api/src/graphql/typeDefs.

ts
import { gql } from "@saruni/api";
export const typeDefs = gql`
  type User {
    id: Int!
    username: String!
  }
  type Query {
    getUsers: [User]!
  }
`;

Resolvers

Having defined the structure of our data, we use resolvers to tell our Apollo Server how to fetch (with queries) or modify (with mutations) data associated with a particular type.

Resolvers are stored in the api/src/graphql/resolvers directory and use of the typed Prisma Client we generate often makes for simple functions.

ts
import { PrismaClient } from "@prisma/client";
export const db = new PrismaClient();
export const Query = {
  getUsers: async () => {
    return await db.user.findMany();
  }),
};

Playground

GraphQL Playground is an interactive, in-browser GraphQL IDE, created by Prisma. After launching our development environment, we can find the Playground at localhost:4000/graphql. Without any extra work, we have an auto-updating documentation of our GraphQL API available in the right sidebar.