codesnips

505 code snips · on codesnips 27 days
typescript
import { randomBytes } from 'crypto';
import { Request, Response, NextFunction } from 'express';

interface CspOptions {
  reportOnly?: boolean;
  reportUri?: string;

Content Security Policy headers (defense-in-depth)

security express csp
by codesnips 3 tabs
typescript
import React from "react";

type FallbackProps = {
  error: Error;
  reset: () => void;
};

React Error Boundary + error reporting hook

react frontend error-boundary
by codesnips 3 tabs
typescript
export interface Post {
  id: string;
  body: string;
  liked: boolean;
  likeCount: number;
}

React Query optimistic update for likes

react typescript frontend
by codesnips 3 tabs
typescript
import { cookies } from "next/headers";
import { jwtVerify } from "jose";

export interface Session {
  userId: string;
  role: "user" | "admin";

Next.js Route Handler with auth guard

nextjs route-handlers authentication
by codesnips 3 tabs
typescript
import { Response } from 'express';

type Client = { id: number; res: Response };

const clients = new Map<string, Set<Client>>();
let nextId = 1;

SSE endpoint for server-to-browser events

realtime sse express
by codesnips 3 tabs
typescript
import { NodeSDK } from '@opentelemetry/sdk-node';
import { OTLPTraceExporter } from '@opentelemetry/exporter-trace-otlp-http';
import { BatchSpanProcessor } from '@opentelemetry/sdk-trace-base';
import { getNodeAutoInstrumentations } from '@opentelemetry/auto-instrumentations-node';
import { Resource } from '@opentelemetry/resources';
import {

OpenTelemetry tracing for Node HTTP

observability tracing opentelemetry
by codesnips 3 tabs
typescript
import { Queue } from "bullmq";
import IORedis from "ioredis";

export const connection = new IORedis(process.env.REDIS_URL ?? "redis://localhost:6379", {
  maxRetriesPerRequest: null,
});

BullMQ worker with retries + dead-letter

node redis background-jobs
by codesnips 3 tabs
sql
CREATE TABLE outbox (
    id             BIGSERIAL PRIMARY KEY,
    aggregate_type TEXT        NOT NULL,
    aggregate_id   TEXT        NOT NULL,
    event_type     TEXT        NOT NULL,
    payload        JSONB       NOT NULL,

Transactional outbox in Node (DB write + event)

node postgres reliability
by codesnips 3 tabs
sql
CREATE TABLE posts (
    id           bigint GENERATED ALWAYS AS IDENTITY PRIMARY KEY,
    author_id    bigint NOT NULL REFERENCES authors (id),
    title        text   NOT NULL,
    body         text   NOT NULL,
    published_at timestamptz NOT NULL DEFAULT now()

Cursor-based pagination with stable ordering

postgres performance pagination
by codesnips 4 tabs
typescript
import { readFileSync } from 'fs';
import { join } from 'path';
import type { Redis } from 'ioredis';
import { randomUUID } from 'crypto';

export interface LimitResult {

Rate limiting by IP + user (Express)

security express redis
by codesnips 4 tabs
typescript
import Redis from "ioredis";

export const redis = new Redis(process.env.REDIS_URL ?? "redis://localhost:6379");

export interface Codec<T> {
  encode(value: T): string;

Redis cache-aside for expensive reads

redis performance caching
by codesnips 3 tabs
typescript
import crypto from 'crypto';

interface VerifyOptions {
  rawBody: Buffer;
  signatureHeader: string | undefined;
  secret: string;

Webhook signature verification (timing-safe compare)

security webhooks hmac
by codesnips 3 tabs