graphql-yoga-dgt
v0.0.2
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Fully-featured GraphQL Server with focus on easy setup, performance & great developer experience
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graphql-yoga
Fully-featured GraphQL Server with focus on easy setup, performance & great developer experience
Overview
- Easiest way to run a GraphQL server: Sensible defaults & includes everything you need with minimal setup.
- Includes Subscriptions: Built-in support for GraphQL subscriptions using WebSockets.
- Compatible: Works with all GraphQL clients (Apollo, Relay...) and fits seamless in your GraphQL workflow.
graphql-yoga
is based on the following libraries & tools:
express
/apollo-server
: Performant, extensible web server frameworkgraphql-subscriptions
/subscriptions-transport-ws
: GraphQL subscriptions servergraphql.js
/graphql-tools
: GraphQL engine & schema helpersgraphql-playground
: Interactive GraphQL IDE
Features
- GraphQL spec-compliant
- File upload
- GraphQL Subscriptions
- TypeScript typings
- GraphQL Playground
- Extensible via Express middleware
- Schema directives
- Apollo Tracing
- Accepts both
application/json
andapplication/graphql
content-types - Runs everywhere: Can be deployed via
now
,up
, AWS Lambda, Heroku etc. - Supports middleware out of the box.
Install
yarn add graphql-yoga
Usage
Quickstart (Hosted demo)
import { GraphQLServer } from 'graphql-yoga'
// ... or using `require()`
// const { GraphQLServer } = require('graphql-yoga')
const typeDefs = `
type Query {
hello(name: String): String!
}
`
const resolvers = {
Query: {
hello: (_, { name }) => `Hello ${name || 'World'}`,
},
}
const server = new GraphQLServer({ typeDefs, resolvers })
server.start(() => console.log('Server is running on localhost:4000'))
To get started with
graphql-yoga
, follow the instructions in the READMEs of the examples.
API
GraphQLServer
constructor(props: Props): GraphQLServer
The props
argument accepts the following fields:
| Key | Type | Default | Note |
| --------------------------- | --------------------------------------------------------------- | ------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| typeDefs
| String
or Function
or DocumentNode
or array
of previous | null
| Contains GraphQL type definitions in SDL or file path to type definitions (required if schema
is not provided *) |
| resolvers
| Object | null
| Contains resolvers for the fields specified in typeDefs
(required if schema
is not provided *) |
| resolverValidationOptions
| Object | null
| Object which controls the resolver validation behaviour (see "Generating a schema") for more information |
| schema
| Object | null
| An instance of GraphQLSchema
(required if typeDefs
and resolvers
are not provided *) |
| mocks
| Object or Boolean | null
| Applies mocks to schema. Setting this to true will apply a default mock, however you can pass an object to customize the mocks similar to the resolvers map. |
| context
| Object or Function | {}
| Contains custom data being passed through your resolver chain. This can be passed in as an object, or as a Function with the signature (req: ContextParameters) => any
** |
| schemaDirectives
| Object | null
| Apollo Server schema directives
that allow for transforming schema types, fields, and arguments |
| middlewares
| array
of Middleware | []
| A list of GraphQLMiddleware
middleware. |
(*) There are two major ways of providing the schema information to the
constructor
:
- Provide
typeDefs
andresolvers
and omit theschema
, in this casegraphql-yoga
will construct theGraphQLSchema
instance usingmakeExecutableSchema
fromgraphql-tools
.- Provide the
schema
directly and omittypeDefs
andresolvers
.
(**) Notice that the
req
argument is an object of the shape{ request, response, connection }
which either carries arequest: Request
property (when it's aQuery
/Mutation
resolver),response: Response
property (when it's aQuery
/Mutation
resolver), or aconnection: SubscriptionOptions
property (when it's aSubscription
resolver).Request
is imported from Express.js.Response
is imported from Express.js aswell.SubscriptionOptions
is from thegraphql-subscriptions
package.SubscriptionOptions
are getting theconnectionParams
automatically injected underSubscriptionOptions.context.[CONNECTION_PARAMETER_NAME]
Here is example of creating a new server:
const typeDefs = `
type Query {
hello(name: String): String!
}
`
const resolvers = {
Query: {
hello: (_, { name }) => `Hello ${name || 'World'}`,
},
}
const server = new GraphQLServer({ typeDefs, resolvers })
start(options: Options, callback: ((options: Options) => void) = (() => null)): Promise<void>
Once your GraphQLServer
is instantiated, you can call the start
method on it. It takes two arguments: options
, the options object defined above, and callback
, a function that's invoked right before the server is started. As an example, the callback
can be used to print information that the server has started.
The options
object has the following fields:
| Key | Type | Default | Note |
| ------------------------ | ---------------------------------------------------------------- | ------------------------------------------------------------------------------------------------ | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| cors
| Object | null
| Contains configuration options for cors |
| tracing
| Boolean or TracingOptions | 'http-header'
| Indicates whether Apollo Tracing should be enabled or disabled for your server (if a string is provided, accepted values are: 'enabled'
, 'disabled'
, 'http-header'
) |
| port
| Number or String | 4000
| Determines the port your server will be listening on (note that you can also specify the port by setting the PORT
environment variable) |
| endpoint
| String | '/'
| Defines the HTTP endpoint of your server |
| subscriptions
| Object or String or false
| '/'
| Defines the subscriptions (websocket) endpoint for your server; accepts an object with subscription server options path
, keepAlive
, onConnect
and onDisconnect
; setting to false
disables subscriptions completely |
| playground
| String or false
| '/'
| Defines the endpoint where you can invoke the Playground; setting to false
disables the playground endpoint |
| defaultPlaygroundQuery
| String | undefined
| Defines default query displayed in Playground. |
| uploads
| UploadOptions or false
or undefined
| null
| Provides information about upload limits; the object can have any combination of the following three keys: maxFieldSize
, maxFileSize
, maxFiles
; each of these have values of type Number; setting to false
disables file uploading |
| https
| HttpsOptions or undefined
| undefined
| Enables HTTPS support with a key/cert |
| getEndpoint
| String or Boolean | false
| Adds a graphql HTTP GET endpoint to your server (defaults to endpoint
if true
). Used for leveraging CDN level caching. |
| deduplicator
| Boolean | true
| Enables graphql-deduplicator. Once enabled sending the header X-GraphQL-Deduplicate
will deduplicate the data. |
| bodyParserOptions
| BodyParserJSONOptions | BodyParserJSONOptions Defaults | Allows pass through of body-parser options |
Additionally, the options
object exposes these apollo-server
options:
| Key | Type | Note |
| ----------------- | -------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| cacheControl
| Boolean | Enable extension that returns Cache Control data in the response |
| formatError
| Number | A function to apply to every error before sending the response to clients. Defaults to defaultErrorFormatter. Please beware, that if you override this, requestId
and code
on errors won't automatically be propagated to your yoga server |
| logFunction
| LogFunction | A function called for logging events such as execution times |
| rootValue
| any | RootValue passed to GraphQL execution |
| validationRules
| Array of functions | Additional GraphQL validation rules to be applied to client-specified queries |
| fieldResolver
| GraphQLFieldResolver | Specify a custom default field resolver function |
| formatParams
| Function | A function applied to each query in a batch to format parameters before execution |
| formatResponse
| Function | A function applied to each response after execution |
| debug
| boolean | Print additional debug logging if execution errors occur |
const options = {
port: 8000,
endpoint: '/graphql',
subscriptions: '/subscriptions',
playground: '/playground',
}
server.start(options, ({ port }) =>
console.log(
`Server started, listening on port ${port} for incoming requests.`,
),
)
PubSub
See the original documentation in graphql-subscriptions
.
mocking
Mocking the schema is straight forward, along wit
import { GraphqlServer, MockList } from 'graphql-yoga'
const typeDefs = `
type Query {
hello(name: String): String!
listOfStrings: [String]
}
`
const mocks = {
Query: () => ({
hello: () => 'Hello World',
listOfStrings: () => new MockList([2, 6]),
}),
}
const server = new GraphQLServer({ typeDefs, mocks })
Endpoints
Examples
There are three examples demonstrating how to quickly get started with graphql-yoga
:
- hello-world: Basic setup for building a schema and allowing for a
hello
query. - subscriptions: Basic setup for using subscriptions with a counter that increments every 2 seconds and triggers a subscription.
- fullstack: Fullstack example based on
create-react-app
demonstrating how to query data fromgraphql-yoga
with Apollo Client 2.0.
Workflow
Once your graphql-yoga
server is running, you can use GraphQL Playground out of the box – typically running on localhost:4000
. (Read here for more information.)
Deployment
now
To deploy your graphql-yoga
server with now
, follow these instructions:
- Download Now Desktop
- Navigate to the root directory of your
graphql-yoga
server - Run
now
in your terminal
Heroku
To deploy your graphql-yoga
server with Heroku, follow these instructions:
- Download and install the Heroku Command Line Interface (previously Heroku Toolbelt)
- Log in to the Heroku CLI with
heroku login
- Navigate to the root directory of your
graphql-yoga
server - Create the Heroku instance by executing
heroku create
- Deploy your GraphQL server by executing
git push heroku master
up
(Coming soon 🔜 )
AWS Lambda (Coming soon 🔜 )
FAQ
How does graphql-yoga
compare to apollo-server
and other tools?
As mentioned above, graphql-yoga
is built on top of a variety of other packages, such as graphql.js
, express
and apollo-server
. Each of these provides a certain piece of functionality required for building a GraphQL server.
Using these packages individually incurs overhead in the setup process and requires you to write a lot of boilerplate. graphql-yoga
abstracts away the initial complexity and required boilerplate and lets you get started quickly with a set of sensible defaults for your server configuration.
graphql-yoga
is like create-react-app
for building GraphQL servers.
Can't I just setup my own GraphQL server using express
and graphql.js
?
graphql-yoga
is all about convenience and a great "Getting Started" experience by abstracting away the complexity that comes when you're building your own GraphQL server from scratch. It's a pragmatic approach to bootstrap a GraphQL server, much like how create-react-app
removes friction when first starting out with React.
Whenever the defaults of graphql-yoga
are too tight a corset for you, you can simply eject from it and use the tooling it's built upon - there's no lock-in or any other kind of magic going on preventing you from doing this.
How to eject from the standard express
setup?
The core value of graphql-yoga
is that you don't have to write the boilerplate required to configure your express.js application. However, once you need to add more customized behaviour to your server, the default configuration provided by graphql-yoga
might not suit your use case any more. For example, it might be the case that you want to add more custom middleware to your server, like for logging or error reporting.
For these cases, GraphQLServer
exposes the express.Application
directly via its express
property:
server.express.use(myMiddleware())
Middleware can also be added specifically to the GraphQL endpoint route, by using:
server.express.post(server.options.endpoint, myMiddleware())
Any middleware you add to that route, will be added right before the apollo-server-express
middleware.
Help & Community
Join our Slack community if you run into issues or have questions. We love talking to you!