codesnips
ruby 
class AddSettingsToAccounts < ActiveRecord::Migration[7.1]
  disable_ddl_transaction!

  def change
    add_column :accounts, :settings, :jsonb, null: false, default: {}

Postgres JSONB Partial Index for Feature Flags

rails postgres jsonb
by codesnips 3 tabs
ruby 
class AddSearchVectorToArticles < ActiveRecord::Migration[7.1]
  def up
    execute <<~SQL
      ALTER TABLE articles
      ADD COLUMN search_vector tsvector
      GENERATED ALWAYS AS (

Multi-Column Full Text Search with tsvector

rails postgres search
by codesnips 3 tabs
ruby 
class AttachmentContentTypeValidator < ActiveModel::EachValidator
  SIGNATURES = {
    "image/png"       => ["\x89PNG\r\n\x1a\n".b],
    "image/jpeg"      => ["\xFF\xD8\xFF".b],
    "image/gif"       => ["GIF87a".b, "GIF89a".b],
    "application/pdf" => ["%PDF-".b]

Safer File Attachments: Content Type + Size Validation

rails security active-storage
by codesnips 4 tabs
ruby 
module EmailNormalization
  extend ActiveSupport::Concern

  included do
    attr_accessor :soft_warnings

Soft Validation: Normalize + Validate Email

rails activerecord validations
by codesnips 4 tabs
ruby 
module QueryBudget
  class Counter
    IGNORED = %w[SCHEMA CACHE TRANSACTION].freeze

    attr_reader :count

Per-Request Query Budget (Detect Runaway Pages)

rails performance observability
by codesnips 4 tabs
ruby 
class SlidingWindowLimiter
  Result = Struct.new(:allowed, :count, :limit, :window_ms, keyword_init: true)

  SCRIPT = <<~LUA.freeze
    local key = KEYS[1]
    local now = tonumber(ARGV[1])

Rate Limiting with Redis + Increment Expiry

rails redis reliability
by codesnips 3 tabs
ruby 
class CreateSubscriptions < ActiveRecord::Migration[7.1]
  STATUSES = %w[pending active past_due canceled].freeze

  def change
    create_table :subscriptions do |t|
      t.references :account, null: false, foreign_key: true

Schema-Backed Enums (DB Constraint + Rails enum)

rails postgres schema
by codesnips 3 tabs
ruby 
class LeaderboardCache
  TOP_KEY = "leaderboard:top".freeze
  STATS_KEY = "leaderboard:stats".freeze

  def top_players
    Rails.cache.fetch(TOP_KEY, expires_in: 5.minutes, race_condition_ttl: 15.seconds) do

Cache Stampede Protection with race_condition_ttl

rails caching performance
by codesnips 3 tabs
ruby 
module ConditionalGet
  extend ActiveSupport::Concern

  private

  def render_conditional(resource, extra: nil)

ETag + Conditional GET for JSON API

rails performance http-caching
by codesnips 2 tabs
ruby 
class Document < ApplicationRecord
  belongs_to :owner, class_name: "User"
  has_many :visibilities, class_name: "DocumentVisibility", dependent: :delete_all

  scope :public_documents, -> { where(is_public: true) }

Polymorphic “Visible To” Scope with Arel

rails activerecord arel
by codesnips 3 tabs
ruby 
class Order < ApplicationRecord
  include TransactionalEnqueue

  belongs_to :customer
  has_many :line_items, dependent: :destroy

Transaction-Safe After-Commit Hook (Avoid Ghost Jobs)

rails activerecord background-jobs
by codesnips 4 tabs
ruby 
class Post < ApplicationRecord
  has_many :comments, dependent: :destroy

  # comments_count is maintained by counter_cache on Comment#belongs_to

  scope :stale_comment_counts, lambda {

Counter Cache Repair Job (Consistency Tooling)

rails activerecord counter-cache
by codesnips 3 tabs