typescript
export type Settled<R> =
  | { status: 'fulfilled'; value: R }
  | { status: 'rejected'; reason: unknown };

export interface ConcurrencyOptions {
  limit: number;

Simple concurrency limiter for batch operations

node concurrency async
by codesnips 2 tabs
typescript
import { defineConfig } from 'vite';
import react from '@vitejs/plugin-react';
import { fileURLToPath, URL } from 'node:url';

const resolvePath = (relative: string): string =>
  fileURLToPath(new URL(relative, import.meta.url));

TypeScript path aliases (tsconfig + bundler)

typescript tooling vite
by codesnips 4 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 DataLoader from "dataloader";
import { Pool } from "pg";

export interface User { id: number; name: string; }
export interface Post { id: number; user_id: number; title: string; }

N+1 avoidance with DataLoader (GraphQL)

graphql performance dataloader
by codesnips 3 tabs
typescript
import crypto from 'node:crypto';

export function base64url(buf: Buffer) {
  return buf.toString('base64').replace(/+/g, '-').replace(///g, '_').replace(/=+$/g, '');
}

OAuth PKCE flow (high level helper)

auth security oauth
by Mateo Rodriguez 1 tab
typescript
import { Request, Response } from 'express';
import { authenticate } from './auth.service';

export async function login(req: Request, res: Response): Promise<void> {
  const { email, password } = req.body ?? {};

Password hashing with Argon2

security node argon2
by codesnips 3 tabs
typescript
import * as Sentry from "@sentry/react";

const environment = import.meta.env.VITE_ENVIRONMENT ?? "development";
const isProd = environment === "production";

export function initSentry(): void {

Sentry initialization with release + environment

observability frontend sentry
by codesnips 3 tabs
typescript
import { z } from "zod";

const booleanFromString = z.preprocess((val) => {
  if (typeof val !== "string") return val;
  return ["true", "1", "yes", "on"].includes(val.toLowerCase());
}, z.boolean());

Typed env parsing with zod

typescript zod validation
by codesnips 3 tabs
typescript
import { useEffect, RefObject } from "react";

const TABBABLE =
  'a[href],button:not([disabled]),textarea:not([disabled]),input:not([disabled]),select:not([disabled]),[tabindex]:not([tabindex="-1"])';

export function useFocusTrap(

Accessible modal with focus trap

react a11y accessibility
by codesnips 4 tabs
typescript
import { useCallback, useEffect, useState } from "react";

interface Options {
  rootMargin?: string;
  threshold?: number;
}

IntersectionObserver infinite scroll hook

react hooks intersection-observer
by codesnips 3 tabs
typescript
import { useEffect, useState } from "react";

export function useDebounce<T>(value: T, delay = 300): T {
  const [debounced, setDebounced] = useState<T>(value);

  useEffect(() => {

Debounced search input (React)

react hooks debounce
by codesnips 3 tabs
typescript
export interface RetryOptions {
  retries: number;
  baseMs: number;
  maxMs: number;
  signal?: AbortSignal;
  onRetry?: (attempt: number, delay: number, err: unknown) => void;

Exponential backoff with jitter for retries

typescript reliability retry
by codesnips 2 tabs