ruby
Rails.application.config.middleware.insert_before 0, Rack::Cors do
  # Development CORS - allow any localhost
  allow do
    origins(
      /http:\/\/localhost:\d+/,
      /http:\/\/127\.0\.0\.1:\d+/,

CORS configuration for Rails APIs

rails cors security
by Maya Patel 1 tab
typescript
import { memo } from 'react'
import { Post } from '@/types'

interface PostListItemProps {
  post: Post
  onLike: (id: string) => void

React memo for component optimization

react performance optimization
by Maya Patel 2 tabs
ruby
Rails.application.configure do
  # Bullet configuration
  config.after_initialize do
    Bullet.enable = true
    Bullet.alert = true # Show JavaScript alert
    Bullet.bullet_logger = true # Log to bullet.log

Rails N+1 query detection with Bullet

rails performance n-1
by Maya Patel 3 tabs
typescript
import { useEffect } from 'react'

interface KeyboardHandlers {
  [key: string]: () => void
}

Keyboard navigation and focus management

react accessibility keyboard
by Maya Patel 2 tabs
ruby
FactoryBot.define do
  factory :post do
    association :author, factory: :user
    sequence(:title) { |n| "Post Title #{n}" }
    body { Faker::Lorem.paragraphs(number: 3).join("\n\n") }
    status { :draft }

Rails fixtures vs factories for test data

rails testing fixtures
by Maya Patel 2 tabs
typescript
import { ReactNode, useEffect, useState } from 'react'
import { createPortal } from 'react-dom'

interface PortalProps {
  children: ReactNode
  container?: Element

React portals for rendering outside component tree

react portals dom
by Maya Patel 2 tabs
ruby
class AddStatusToPosts < ActiveRecord::Migration[6.1]
  # Use change for automatic rollback
  def change
    # Add column without default to avoid table lock
    add_column :posts, :status, :string

Rails database migrations best practices

rails migrations database
by Maya Patel 3 tabs
typescript
import { Suspense } from 'react'
import { useSuspenseQuery } from '@tanstack/react-query'
import { useParams } from 'react-router-dom'
import api from '@/services/api'
import { Post } from '@/types'
import { ErrorBoundary } from '@/components/ErrorBoundary'

React Suspense for data fetching

react suspense async-loading
by Maya Patel 1 tab
ruby
class Post < ApplicationRecord
  # View counter - increments without hitting the database
  kredis_counter :view_count, expires_in: 1.day

  # Recent viewers list - stores last 10 viewer IDs
  kredis_unique_list :recent_viewers, limit: 10

Rails Kredis for higher-level Redis operations

rails redis kredis
by Maya Patel 2 tabs
typescript
import { useState, useMemo, useCallback } from 'react'
import { Post } from '@/types'
import { PostCard } from './PostCard'

interface FilteredPostsProps {
  posts: Post[]

Memoization in React with useMemo and useCallback

react performance memoization
by Maya Patel 1 tab
ruby
module Paginatable
  extend ActiveSupport::Concern

  included do
    before_action :set_pagination_params, only: [:index]
  end

Rails concerns for shared controller behavior

rails concerns controllers
by Maya Patel 2 tabs
typescript
import { ReactNode } from 'react'

interface CardProps {
  children: ReactNode
  className?: string
}

React component composition over inheritance

react patterns composition
by Maya Patel 2 tabs