@graphql-yoga/plugin-response-cache/esm/index.js

For the documentation check `http://graphql-yoga.com/docs/response-cache`

import { defaultBuildResponseCacheKey, createInMemoryCache as envelopCreateInMemoryCache, resultWithMetadata, useResponseCache as useEnvelopResponseCache, } from '@envelop/response-cache';
const operationIdByRequest = new WeakMap();
const sessionByRequest = new WeakMap();
function sessionFactoryForEnvelop({ request }) {
    return sessionByRequest.get(request);
}
const cacheKeyFactoryForEnvelop = async function cacheKeyFactoryForEnvelop({ context }) {
    const request = context.request;
    if (request == null) {
        throw new Error('[useResponseCache] This plugin is not configured correctly. Make sure you use this plugin with GraphQL Yoga');
    }
    const operationId = operationIdByRequest.get(request);
    if (operationId == null) {
        throw new Error('[useResponseCache] This plugin is not configured correctly. Make sure you use this plugin with GraphQL Yoga');
    }
    return operationId;
};
const getDocumentStringForEnvelop = executionArgs => {
    const context = executionArgs.contextValue;
    if (context.params?.query == null) {
        throw new Error('[useResponseCache] This plugin is not configured correctly. Make sure you use this plugin with GraphQL Yoga');
    }
    return context.params.query;
};
export function useResponseCache(options) {
    const buildResponseCacheKey = options?.buildResponseCacheKey || defaultBuildResponseCacheKey;
    const cache = options.cache ?? createInMemoryCache();
    const enabled = options.enabled ?? (() => true);
    let logger;
    return {
        onYogaInit({ yoga }) {
            logger = yoga.logger;
        },
        onPluginInit({ addPlugin }) {
            addPlugin(useEnvelopResponseCache({
                ...options,
                enabled({ request }) {
                    return enabled(request);
                },
                cache,
                getDocumentString: getDocumentStringForEnvelop,
                session: sessionFactoryForEnvelop,
                buildResponseCacheKey: cacheKeyFactoryForEnvelop,
                shouldCacheResult({ cacheKey, result }) {
                    const shouldCached = options.shouldCacheResult
                        ? options.shouldCacheResult({ cacheKey, result })
                        : !result.errors?.length;
                    if (shouldCached) {
                        const extensions = (result.extensions ||= {});
                        const httpExtensions = (extensions.http ||= {});
                        const headers = (httpExtensions.headers ||= {});
                        headers['ETag'] = cacheKey;
                        headers['Last-Modified'] = new Date().toUTCString();
                    }
                    else {
                        logger.warn('[useResponseCache] Failed to cache due to errors');
                    }
                    return shouldCached;
                },
            }));
        },
        async onRequest({ request, fetchAPI, endResponse }) {
            if (enabled(request)) {
                const operationId = request.headers.get('If-None-Match');
                if (operationId) {
                    const cachedResponse = await cache.get(operationId);
                    if (cachedResponse) {
                        const lastModifiedFromClient = request.headers.get('If-Modified-Since');
                        const lastModifiedFromCache = cachedResponse.extensions?.http?.headers?.['Last-Modified'];
                        if (
                        // This should be in the extensions already but we check it here to make sure
                        lastModifiedFromCache != null &&
                            // If the client doesn't send If-Modified-Since header, we assume the cache is valid
                            (lastModifiedFromClient == null ||
                                new Date(lastModifiedFromClient).getTime() >=
                                    new Date(lastModifiedFromCache).getTime())) {
                            const okResponse = new fetchAPI.Response(null, {
                                status: 304,
                                headers: {
                                    ETag: operationId,
                                },
                            });
                            endResponse(okResponse);
                        }
                    }
                }
            }
        },
        async onParams({ params, request, setResult }) {
            const sessionId = await options.session(request);
            const operationId = await buildResponseCacheKey({
                documentString: params.query || '',
                variableValues: params.variables,
                operationName: params.operationName,
                sessionId,
                request,
            });
            operationIdByRequest.set(request, operationId);
            sessionByRequest.set(request, sessionId);
            if (enabled(request)) {
                const cachedResponse = await cache.get(operationId);
                if (cachedResponse) {
                    if (options.includeExtensionMetadata) {
                        setResult(resultWithMetadata(cachedResponse, { hit: true }));
                    }
                    else {
                        setResult(cachedResponse);
                    }
                    return;
                }
            }
        },
    };
}
export const createInMemoryCache = envelopCreateInMemoryCache;