How To Make A GraphQL Server With Bun.

UPDATE 2/4/2023 - I have a new blogpost for a much better method of running a GraphQL server with Bun here with Apollo Server

This is my first post on my new blog, how exciting!

Today, I was trying to find an example of how to make a GraphQL server with Bun, but I couldn't find one. I decided to create one instead.

You can read all about Bun here bun.sh.

Bun has a lot of the Node API built in, but it provides its own, faster, HTTP server. This causes incompatibilities with the traditional methods I use to create a GraphQL server (Apollo Server or ExpressJS). Thankfully, Hono is compatible with Bun. It claims to be "a small, simple, and ultrafast web framework for Cloudflare Workers, Deno, Bun, and others."

Additionally, luck would have it, there is a new package for GraphQL Server with Hono which we can utilize to get a GraphQL server up and running. It was build as a fork of graphql-express, and it depends on the GraphQL.js package to work.

The GraphQL.js package does not fully support Bun at this time, but we only need one part of it in order to get this server to work, the buildSchema function.

Now to get started:

Install Bun:

curl -fsSL https://bun.sh/install | bash

Create a new project. I personally did npm init to create a package.json file.

mkdir bun-graphql
cd bun-graphql
npm init

We'll need a few dependencies:

bun add graphql
bun add hono
bun add @honojs/graphql-server

Create an index.js file and add the following code:

import { Hono } from 'hono'
import { graphqlServer } from '@honojs/graphql-server'
import { buildSchema } from 'graphql/utilities/buildASTSchema.js'

// Initialize Hono
export const app = new Hono()

// Builds schema from a string
const schema = buildSchema(`
  type Query {
    hello: String
  }
`)

// Resolvers
const rootResolver = (ctx) => {
  return {
    hello: () => 'Hello Hono!',
  }
}

// Hono.js GraphQL Server
app.use(
  '/graphql',
  graphqlServer({
    schema,
    rootResolver,
  })
)

// Set the default port to 3000, or use the PORT environment variable
const port = process.env.PORT || 3000

console.log(`Hono 🥟 GraphQL Server Listening on port ${port}`)

export default {
  port,
  fetch: app.fetch,
}

This is based off the example file from Hono's GraphQL Server package, but tweaked to match Hono's Bun example.

It's important to import buildSchema directly from ''graphql/utilities/buildASTSchema.js', otherwise your app will fail because the GraphQL.js library isn't fully Bun compatible, but this essential function is.

Run the server:

bun index.js

You won't see any logs in the console, but you should see a GraphQL server running if you query the endpoint. http://localhost:3000/graphql

Let's deploy this app using a Dockerfile. Create a new file called Dockerfile and add the following code:

FROM jarredsumner/bun:0.5.1
WORKDIR /app
COPY package.json package.json
COPY bun.lockb bun.lockb
RUN bun install
COPY index.js index.js
EXPOSE 3000
ENTRYPOINT ["bun", "index.js"]

You can test the Dockerfile locally if you have Docker installed by running the following command:

docker build -t bun-graphql .

docker run -p 3000:3000 bun-graphql

Commit and push up the code to a new repository. I suggest adding node_modules/ to the .gitignore file.
I deployed using Render, but there are tons of options to deploy an application in a Docker Container.

I selected "New +" and then selected "Web Service". Once I connected my repository to the service, it detected my Dockerfile and was building and deploying in minutes.

To test that deployment works, run the same hello query against the GraphQL server on the newly deployed endpoint.

Congrats, if everything worked you have a GraphQL server running on Bun in the cloud!

You can find the source code for my example GraphQL Server w/ Bun on GitHub here. The code is going to look a bit different than the example here in this blog because I added GraphQL Playground and I'm reading my schema from a graphql.schema file.