@graphql-mesh/serve-runtime/esm/useContentEncoding.js

import { useContentEncoding as useOrigContentEncoding } from '@whatwg-node/server';
export function useContentEncoding({ subgraphs, }) {
    if (!subgraphs?.length) {
        return useOrigContentEncoding();
    }
    const compressionAlgorithm = 'gzip';
    let fetchAPI;
    const execReqWithContentEncoding = new WeakSet();
    return {
        onYogaInit({ yoga }) {
            fetchAPI = yoga.fetchAPI;
        },
        onPluginInit({ addPlugin }) {
            addPlugin(
            // @ts-expect-error - Typings are wrong
            useOrigContentEncoding());
        },
        onSubgraphExecute({ subgraphName, executionRequest }) {
            if (subgraphs.includes(subgraphName)) {
                execReqWithContentEncoding.add(executionRequest);
            }
        },
        onFetch({ executionRequest, options, setOptions }) {
            if (options.body &&
                !options.headers?.['Content-Encoding'] &&
                execReqWithContentEncoding.has(executionRequest)) {
                const compressionStream = new fetchAPI.CompressionStream(compressionAlgorithm);
                let bodyStream;
                if (options.body instanceof fetchAPI.ReadableStream) {
                    bodyStream = options.body;
                }
                else {
                    // Create a fake Response and use its body to pipe through the compression stream
                    bodyStream = new fetchAPI.Response(options.body).body;
                }
                setOptions({
                    ...options,
                    headers: {
                        'Accept-Encoding': 'gzip, deflate',
                        ...options.headers,
                        'Content-Encoding': compressionAlgorithm,
                    },
                    body: bodyStream.pipeThrough(compressionStream),
                });
            }
        },
    };
}