feat: variable batching

.changeset/quiet-owls-occur.md

@@ -0,0 +1,5 @@
+---
+'graphql-yoga': minor
+---
+
+Support variable batching

packages/graphql-yoga/__tests__/batching.spec.ts

@@ -7,12 +7,14 @@ describe('Batching', () => {
  type Query {
  hello: String
  bye: String
+ greetings(name: String!): String!
  }
  `,
  resolvers: {
  Query: {
  hello: () => 'hello',
  bye: () => 'bye',
+ greetings: (_root, { name }) => `hello, ${name}`,
  },
  },
  });
@@ -287,4 +289,32 @@ describe('Batching', () => {
  ],
  });
  });
+ it('variable batching', async () => {
+ const yoga = createYoga({
+ schema,
+ batching: {},
+ });
+ const query = /* GraphQL */ `
+ query ($name: String!) {
+ greetings(name: $name)
+ }
+ `;
+ const res = await yoga.fetch('http://yoga/graphql', {
+ method: 'POST',
+ headers: {
+ accept: 'application/graphql-response+json',
+ 'Content-Type': 'application/json',
+ },
+ body: JSON.stringify({
+ query,
+ variables: [{ name: 'Alice' }, { name: 'Bob' }, { name: 'Charlie' }],
+ }),
+ });
+ const result = await res.json();
+ expect(result).toEqual([
+ { data: { greetings: 'hello, Alice' } },
+ { data: { greetings: 'hello, Bob' } },
+ { data: { greetings: 'hello, Charlie' } },
+ ]);
+ });
 });

packages/graphql-yoga/src/server.ts

@@ -67,6 +67,7 @@ import {
  YogaMaskedErrorOpts,
 } from './types.js';
 import { maskError } from './utils/mask-error.js';
+import { processBatchedParams } from './utils/process-batched-params.js';
 
 /**
  * Configuration options for the server
@@ -535,6 +536,8 @@ export class YogaServer<
  });
  }
 
+ requestParserResult = processBatchedParams(requestParserResult);
+
  const result = (await (Array.isArray(requestParserResult)
  ? Promise.all(
  requestParserResult.map(params =>

packages/graphql-yoga/src/utils/process-batched-params.ts

@@ -0,0 +1,16 @@
+import { GraphQLParams } from '../types.js';
+
+export function processBatchedParams(
+ params: GraphQLParams | GraphQLParams[],
+): GraphQLParams | GraphQLParams[] {
+ if (Array.isArray(params)) {
+ return params.map(param => processBatchedParams(param)).flat();
+ }
+ if (Array.isArray(params.variables)) {
+ return params.variables.map(variables => ({
+ ...params,
+ variables,
+ }));
+ }
+ return params;
+}