express-api-limiter/dist/rateLimiter.js

express-api-rate-limit is a simple and customizable rate-limiting middleware for Express.js applications, designed to prevent abuse by restricting the number of requests a client can make within a specified time window. This package allows you to define d

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.RateLimiter = void 0;
/**
 * RateLimiter Class to handle rate-limiting logic
 */
class RateLimiter {
    constructor() {
        this.requestCounts = new Map();
        /**
         * Middleware function to limit API requests
         * @param {RateLimitOptions} options - Rate limit parameters for this particular request
         */
        this.middleware = (options) => {
            return (req, res, next) => {
                const currentTime = Date.now();
                // Ensure the client IP is always a string
                const clientIp = req.ip || "unknown"; // Default to 'unknown' if req.ip is undefined
                if (!this.requestCounts.has(clientIp)) {
                    this.requestCounts.set(clientIp, []);
                }
                // Get the list of timestamps for the client's requests
                const timestamps = this.requestCounts.get(clientIp);
                // Remove timestamps older than the time window
                const validTimestamps = timestamps.filter((timestamp) => currentTime - timestamp < options.windowMs * 60 * 1000);
                if (validTimestamps.length >= options.maxCalls) {
                    // If the number of requests exceeds the limit, respond with an error
                    return res.status(429).json({
                        message: `Too many requests. Please try again after ${options.windowMs} minute(s).`
                    });
                }
                // Add the current timestamp
                validTimestamps.push(currentTime);
                this.requestCounts.set(clientIp, validTimestamps);
                // Proceed to the next middleware/handler
                next();
            };
        };
    }
}
exports.RateLimiter = RateLimiter;