Optimized JSON HTTP Data Source for Apollo Server
- Uses Undici under the hood. It's around
60%
faster thanapollo-datasource-rest
- Request Deduplication (LRU)
- Support AbortController to manually cancel all running requests
View the Apollo Server documentation for data sources for more details.
To get started, install the @llc1123/apollo-datasource-http
package:
npm install @llc1123/apollo-datasource-http
To define a data source, extend the HTTPDataSource
class and implement the data fetching methods that your resolvers require. Data sources can then be provided via the dataSources
property to the ApolloServer
constructor, as demonstrated in the section below.
// instantiate a pool outside of your hotpath
const baseURL = 'https://movies-api.example.com'
const pool = new Pool(baseURL)
const server = new ApolloServer({
typeDefs,
resolvers,
dataSources: () => {
return {
moviesAPI: new MoviesAPI(baseURL, pool),
}
},
})
Your implementation of these methods can call on convenience methods built into the HTTPDataSource class to perform HTTP requests, while making it easy to pass different options and handle errors.
import { Pool } from 'undici'
import { HTTPDataSource } from '@llc1123/apollo-datasource-http'
const datasource = new (class MoviesAPI extends HTTPDataSource {
constructor(baseURL: string, pool: Pool) {
// global client options
super(baseURL, {
pool,
clientOptions: {
bodyTimeout: 5000,
headersTimeout: 2000,
},
requestOptions: {
headers: {
'X-Client': 'client',
},
},
})
}
onCacheKeyCalculation(request: Request): string {
// return different key based on request options
}
async onRequest(request: Request): Promise<void> {
// manipulate request before it is send
// for example assign a AbortController signal to all requests and abort
request.signal = this.context.abortController.signal
setTimeout(() => {
this.context.abortController.abort()
}, 3000).unref()
}
onResponse<TResult = unknown>(request: Request, response: Response<TResult>): Response<TResult> {
// manipulate response or handle unsuccessful response in a different way
return super.onResponse(request, response)
}
onError(error: Error, request: Request): void {
// in case of a request error
if (error instanceof RequestError) {
console.log(error.request, error.response)
}
}
async createMovie() {
return this.post('/movies', {
body: {
name: 'Dude Where\'s My Car',
}
})
}
async getMovie(id) {
return this.get(`/movies/${id}`, {
query: {
a: 1,
},
context: {
tracingName: 'getMovie',
},
headers: {
'X-Foo': 'bar',
},
})
}
})()
onCacheKeyCalculation
- Returns the cache key for request memoization.onRequest
- Is executed before a request is made. This can be used to intercept requests (setting header, timeouts ...).onResponse
- Is executed when a response has been received. This can be used to alter the response before it is passed to caller or to log errors.onError
- Is executed for any request error.
The http client throws for unsuccessful responses (statusCode >= 400). In case of an request error onError
is executed. By default the error is rethrown as a ApolloError
to avoid exposing sensible information.
We test this software against latest major releases of the Node.js LTS policy. Current
is included to catch regression earlier.