@graphql-yoga/plugin-graphql-sse/esm/index.js

GraphQL over Server-Sent Events Protocol plugin for GraphQL Yoga.

import { getOperationAST } from 'graphql';
import { createHandler } from 'graphql-sse/lib/use/fetch';
/**
 * Get [GraphQL over Server-Sent Events Protocol](https://github.com/enisdenjo/graphql-sse/blob/master/PROTOCOL.md) integration with GraphQL Yoga by simply installing this plugin!
 *
 * Note that the endpoint defaults to `/graphql/stream`, this is where your [graphql-sse](https://github.com/enisdenjo/graphql-sse) client should connect.
 */
export function useGraphQLSSE(options = {}) {
    const { endpoint = '/graphql/stream', ...handlerOptions } = options;
    // eslint-disable-next-line @typescript-eslint/no-explicit-any
    const ctxForReq = new WeakMap();
    let handler;
    return {
        onYogaInit({ yoga }) {
            handler = createHandler({
                ...handlerOptions,
                async onSubscribe(req, params) {
                    const enveloped = yoga.getEnveloped({
                        ...ctxForReq.get(req.raw),
                        request: req.raw,
                        params,
                    });
                    const document = enveloped.parse(params.query);
                    const errors = enveloped.validate(enveloped.schema, document);
                    if (errors.length > 0) {
                        return { errors };
                    }
                    const contextValue = await enveloped.contextFactory();
                    const executionArgs = {
                        schema: enveloped.schema,
                        document,
                        contextValue,
                        variableValues: params.variables,
                        operationName: params.operationName,
                    };
                    const operation = getOperationAST(document, params.operationName);
                    const executeFn = operation?.operation === 'subscription'
                        ? enveloped.subscribe
                        : enveloped.execute;
                    return executeFn(executionArgs);
                },
            }, yoga.fetchAPI);
        },
        async onRequest({ request, endResponse, serverContext }) {
            const [path, _search] = request.url.split('?');
            if (path.endsWith(endpoint)) {
                ctxForReq.set(request, serverContext);
                endResponse(await handler(request));
            }
        },
    };
}