middleware

typescript
import type { IncomingMessage, ServerResponse } from "http";

const MIN_BYTES = 1024;

const INCOMPRESSIBLE = /^(image|video|audio)\/|application\/(zip|gzip|x-brotli|pdf|octet-stream)/i;

Response compression (only when it helps)

performance http express
by codesnips 3 tabs
typescript
import pino, { Logger } from 'pino';
import { AsyncLocalStorage } from 'node:async_hooks';

export interface Store {
  requestId: string;
  logger: Logger;

Request ID + structured logging (Express + pino)

express logging observability
by codesnips 3 tabs
python
import logging
import time

logger = logging.getLogger(__name__)

Django middleware for request logging and timing

django python middleware
by Priya Sharma 1 tab
ruby
module Middleware
  class DatabasePinning
    PIN_WINDOW = 5.seconds

    def initialize(app)
      @app = app

“Read Your Writes” Consistency: Pin to Primary After POST

rails consistency reliability
by codesnips 4 tabs
ruby
class JsonLogFormatter < ActiveSupport::Logger::SimpleFormatter
  def call(severity, timestamp, _progname, message)
    if message.is_a?(Hash)
      entry = {
        ts: timestamp.utc.iso8601(3),
        level: severity

Lograge-Style JSON Logging Without Extra Gems

rails logging observability
by codesnips 3 tabs
ruby
class TurboFailureApp < Devise::FailureApp
  def respond
    if turbo_request?
      redirect_for_turbo
    else
      super

Handle 401 responses in Turbo by forcing a full redirect

rails hotwire turbo
by codesnips 4 tabs
python
import time
import logging

logger = logging.getLogger(__name__)

Django custom middleware for request/response modification

django python middleware
by Priya Sharma 1 tab
typescript
import express from 'express';
import cookieParser from 'cookie-parser';
import { issueCsrfToken, csrfProtection } from './csrf';
import { transfersRouter } from './routes/transfers';

const app = express();

CSRF protection with double-submit cookie

security express csrf
by codesnips 3 tabs
typescript
import { Registry, Histogram, Counter, collectDefaultMetrics } from 'prom-client';

export const register = new Registry();

collectDefaultMetrics({ register });

Prometheus metrics for request latency

observability node metrics
by codesnips 3 tabs
typescript
import { OpenAPIRegistry, extendZodWithOpenApi } from '@asteasolutions/zod-to-openapi';
import { z } from 'zod';

extendZodWithOpenApi(z);

export const registry = new OpenAPIRegistry();

OpenAPI generation for REST endpoints

typescript openapi zod
by codesnips 4 tabs
typescript
import crypto from 'crypto';
import helmet from 'helmet';
import type { Express, Request, Response, NextFunction } from 'express';

function cspNonce(req: Request, res: Response, next: NextFunction): void {
  res.locals.cspNonce = crypto.randomBytes(16).toString('base64');

Security headers with helmet (baseline hardening)

security express helmet
by codesnips 3 tabs
go
package middleware

import "net/http"

type StatusRecorder struct {
  http.ResponseWriter

Capture status code and bytes written via ResponseWriter wrapper

go http observability
by Leah Thompson 1 tab