codesnips
javascript 
function escapeCell(value) {
  if (value === null || value === undefined) return '';
  const str = String(value);
  if (/[",\n\r]/.test(str)) {
    return '"' + str.replace(/"/g, '""') + '"';
  }

Stream a Large CSV Export in Express with Backpressure and an Async Row Generator

express streaming csv
by codesnips 3 tabs
javascript 
import { useState, useRef, useEffect, useCallback } from 'react';

export function useOnScreen(options = {}) {
  const [node, setNode] = useState(null);
  const [isIntersecting, setIsIntersecting] = useState(false);

Infinite Scroll in React with an IntersectionObserver useOnScreen Hook

react hooks intersection-observer
by codesnips 3 tabs
go 
package httpretry

import (
	"math/rand"
	"time"
)

Exponential Backoff With Full Jitter for Flaky HTTP Calls in Go

go http retry
by codesnips 3 tabs
python 
from alembic import op
import sqlalchemy as sa

revision = "20240612_add_status"
down_revision = "20240515_create_orders"
branch_labels = None

Zero-Downtime NOT NULL Column Backfill with Alembic and SQLAlchemy

alembic sqlalchemy migrations
by codesnips 2 tabs
typescript 
import { EventEmitter } from "events";

export interface Job<T> {
  id: string;
  payload: T;
  attempts: number;

Typed In-Memory Job Queue With a Concurrency-Limited Worker Pool

typescript job-queue concurrency
by codesnips 3 tabs
java 
package com.example.reference;

import jakarta.persistence.Column;
import jakarta.persistence.Entity;
import jakarta.persistence.Id;
import jakarta.persistence.Table;

Seed Reference Data at Boot with a Spring Boot ApplicationRunner

spring-boot seeding reference-data
by codesnips 4 tabs
javascript 
const express = require('express');
const AppError = require('./AppError');
const asyncHandler = require('./asyncHandler');
const errorMiddleware = require('./errorMiddleware');
const UserRepo = require('./UserRepo');

Centralized Express Error Handling with Typed AppError and Async Wrapper

express error-handling middleware
by codesnips 4 tabs
typescript 
import { createContext, useContext, useEffect, useMemo, useState, ReactNode } from 'react';
import { authApi, User } from './authApi';

type Status = 'loading' | 'authenticated' | 'anonymous';

interface AuthValue {

Protect React Routes with an Auth Context and a RequireAuth Wrapper

react react-router authentication
by codesnips 4 tabs
go 
package config

import (
	"encoding/json"
	"fmt"
	"time"

Strict JSON Config Loading in Go with DisallowUnknownFields

go json configuration
by codesnips 3 tabs
ruby 
require 'sinatra/base'
require_relative 'upload_store'

class UploadApp < Sinatra::Base
  MAX_BYTES = 50 * 1024 * 1024

Streaming Multipart File Uploads to Disk in Sinatra Without Buffering

sinatra rack file-upload
by codesnips 3 tabs
go 
package api

import (
	"encoding/json"
	"net/http"
)

Field-Level JSON Validation Errors in Go net/http Handlers

go net-http validation
by codesnips 3 tabs
typescript 
import { Injectable, NestMiddleware, UnauthorizedException } from '@nestjs/common';
import { Request, Response, NextFunction } from 'express';
import { TenantService } from './tenant.service';

@Injectable()
export class TenantContextMiddleware implements NestMiddleware {

Bind Tenant Context Per Request in NestJS With a Custom @TenantId() Decorator

nestjs multi-tenancy decorators
by codesnips 4 tabs