graphql-yoga/esm/plugins/useResultProcessor.js

<div align="center"><img src="./website/public/cover.png" width="720" /></div>

import { isAsyncIterable } from '@envelop/core';
import { getMediaTypesForRequestInOrder, isMatchingMediaType, } from './resultProcessor/accept.js';
import { processMultipartResult } from './resultProcessor/multipart.js';
import { processPushResult } from './resultProcessor/push.js';
import { processRegularResult } from './resultProcessor/regular.js';
const multipart = {
    mediaTypes: ['multipart/mixed'],
    asyncIterables: true,
    processResult: processMultipartResult,
};
const textEventStream = {
    mediaTypes: ['text/event-stream'],
    asyncIterables: true,
    processResult: processPushResult,
};
const regular = {
    mediaTypes: ['application/graphql-response+json', 'application/json'],
    asyncIterables: false,
    processResult: processRegularResult,
};
const defaultList = [textEventStream, multipart, regular];
const subscriptionList = [multipart, textEventStream, regular];
export function useResultProcessors() {
    const isSubscriptionRequestMap = new WeakMap();
    return {
        onSubscribe({ args: { contextValue } }) {
            if (contextValue.request) {
                isSubscriptionRequestMap.set(contextValue.request, true);
            }
        },
        onResultProcess({ request, result, acceptableMediaTypes, setResultProcessor, }) {
            const isSubscriptionRequest = isSubscriptionRequestMap.get(request);
            const processorConfigList = isSubscriptionRequest
                ? subscriptionList
                : defaultList;
            const requestMediaTypes = getMediaTypesForRequestInOrder(request);
            const isAsyncIterableResult = isAsyncIterable(result);
            for (const requestMediaType of requestMediaTypes) {
                for (const resultProcessorConfig of processorConfigList) {
                    if (isAsyncIterableResult && !resultProcessorConfig.asyncIterables) {
                        continue;
                    }
                    for (const processorMediaType of resultProcessorConfig.mediaTypes) {
                        acceptableMediaTypes.push(processorMediaType);
                        if (isMatchingMediaType(processorMediaType, requestMediaType)) {
                            setResultProcessor(resultProcessorConfig.processResult, processorMediaType);
                        }
                    }
                }
            }
        },
    };
}