http-proxy-middleware/dist/plugins/default/proxy-events.js

The one-liner node.js proxy middleware for connect, express, next.js and more

import { Debug } from '../../debug.js';
import { getFunctionName } from '../../utils/function.js';
const debug = Debug.extend('proxy-events-plugin');
/**
 * Implements option.on object to subscribe to `httpxy` events.
 *
 * @example
 * ```js
 * createProxyMiddleware({
 *  on: {
 *    error: (error, req, res, target) => {},
 *    proxyReq: (proxyReq, req, res, options) => {},
 *    proxyReqWs: (proxyReq, req, socket, options) => {},
 *    proxyRes: (proxyRes, req, res) => {},
 *    open: (proxySocket) => {},
 *    close: (proxyRes, proxySocket, proxyHead) => {},
 *    start: (req, res, target) => {},
 *    end: (req, res, proxyRes) => {},
 *    econnreset: (error, req, res, target) => {},
 *  }
 * });
 * ```
 */
export const proxyEventsPlugin = (proxyServer, options) => {
    if (!options.on) {
        return;
    }
    // hoist variable here for better typing
    let eventName;
    // for in provide better typing than Object.entries()
    for (eventName in options.on) {
        if (Object.prototype.hasOwnProperty.call(options.on, eventName)) {
            const handler = options.on[eventName];
            if (!handler) {
                continue;
            }
            debug(`register event handler: "${eventName}" -> "${getFunctionName(handler)}"`);
            proxyServer.on(eventName, handler);
        }
    }
};