codesnips

middleware

typescript 
import { z } from 'zod';

export const createUserSchema = z
  .object({
    email: z.string().email(),
    name: z.string().min(1).max(120),

Runtime validation for request bodies (Zod)

typescript validation api
by codesnips 3 tabs
typescript 
import { NextRequestWithAuth } from 'next/server';
import { NextResponse } from 'next/server';
import type { NextRequest } from 'next/server';
import { verifySession } from './lib/verify-session';
import { isProtected, isAuthPage } from './lib/route-matchers';

Next.js middleware for auth gating

nextjs auth security
by codesnips 3 tabs
python 
from datetime import datetime, timedelta, timezone

from jose import jwt, JWTError
from jose.exceptions import ExpiredSignatureError

SECRET_KEY = "change-me-in-production"

FastAPI JWT Authentication with Access/Refresh Tokens and a Verification Dependency

fastapi jwt authentication
by codesnips 3 tabs
ruby 
class WebhookSignature
  class VerificationError < StandardError; end

  TOLERANCE = 300 # seconds

  def initialize(payload:, header:, secrets:)

Robust Webhook Verification (HMAC + Timestamp)

rails security webhooks
by codesnips 3 tabs
go 
package ratelimit

import (
	"sync"
	"time"
)

Token Bucket Rate-Limiting Middleware for a Go net/http API

go net-http middleware
by codesnips 4 tabs
javascript 
const MAX_LIMIT = 100;
const DEFAULT_LIMIT = 20;
const ALLOWED_ORDER = new Set(['asc', 'desc']);

function decodeCursor(raw) {
  const json = Buffer.from(raw, 'base64').toString('utf8');

Cursor-Based Pagination in Express With Query-Parsing Middleware

express pagination cursor-pagination
by codesnips 3 tabs
ruby 
module RequestStore
  def self.store
    Thread.current[:request_store] ||= {}
  end

  def self.fetch(key)

Hot Path Memoization (within request only)

rails performance memoization
by codesnips 4 tabs
lua 
-- KEYS[1] = bucket key
-- ARGV[1] = capacity, ARGV[2] = refill_per_sec, ARGV[3] = now (float seconds)
local capacity = tonumber(ARGV[1])
local rate = tonumber(ARGV[2])
local now = tonumber(ARGV[3])

Redis-Backed Token Bucket Rate Limiter as FastAPI Middleware

fastapi redis rate-limiting
by codesnips 4 tabs
go 
package main

import (
	"log"
	"net/http"
	"time"

Instrumenting Go HTTP Handlers with Prometheus Counters and Histograms

prometheus metrics observability
by codesnips 3 tabs
javascript 
const multer = require('multer');

const ALLOWED_MIME = new Set(['image/jpeg', 'image/png', 'image/webp']);

function fileFilter(req, file, cb) {
  if (!ALLOWED_MIME.has(file.mimetype)) {

Upload and Resize User Avatars with Multer and Sharp in Express

express multer sharp
by codesnips 3 tabs
ruby 
module QueryBudget
  class Counter
    IGNORED = %w[SCHEMA CACHE TRANSACTION].freeze

    attr_reader :count

Per-Request Query Budget (Detect Runaway Pages)

rails performance observability
by codesnips 4 tabs
php 
<?php

namespace App\Jobs;

use App\Models\Invoice;
use App\Services\StripeGateway;

Preventing Double-Charges in Laravel with WithoutOverlapping Job Middleware

laravel queues background-jobs
by codesnips 3 tabs