Improve rateLimiter.ts

[dgladys]

According to a warning visible when project starts, i suggest use solution proposed in itself.
In theory problem is that req.ip returns only ipv4 ip; if user connect with ipv6 address then rate limiter doesn't work and user can connect to API without limits. Key generated ipKeyGenerator from "express-rate-limit" should be safer.
In fact, in docs of the ipKeyGenerator it's written:

If you write a custom keyGenerator that allows a fallback to IP address for unauthenticated users, return ipKeyGenerator(req.ip) rather than just req.ip
Signature of ipKeyGenerator is:
export declare function ipKeyGenerator(ip: string, ipv6Subnet?: number | false): string;

As you see, two arguments, only first required. Best solution will be if also ipv6Subnet is provided, at this very moment i don't have conditions to verify and test it.

Now i show how to fix it to eliminate warning and increase security of solution, however it still can be improved by providing ipv6subnet when possible.

Suggested changes:

File: src/common/middleware/rateLimiter.ts:2

Before
import { rateLimit } from "express-rate-limit";
After:
import { ipKeyGenerator, rateLimit } from "express-rate-limit";

File: src/common/middleware/rateLimiter.ts:12

Before:
keyGenerator: (req: Request) => req.ip as string,

After
keyGenerator: (req: Request) => ipKeyGenerator(req.ip as string),

src/common/middleware/rateLimiter.ts after changes:

import type { Request } from "express";
import { ipKeyGenerator, rateLimit } from "express-rate-limit";

import { env } from "@/common/utils/envConfig";

const rateLimiter = rateLimit({
	legacyHeaders: true,
	limit: env.COMMON_RATE_LIMIT_MAX_REQUESTS,
	message: "Too many requests, please try again later.",
	standardHeaders: true,
	windowMs: 15 * 60 * env.COMMON_RATE_LIMIT_WINDOW_MS,
	keyGenerator: (req: Request) => ipKeyGenerator(req.ip as string),
});

export default rateLimiter;

Summary

In my case i don't see warning in console anymore.