codesnips
ruby 
class PriceBreakdown < Struct.new(:subtotal_cents, :discount_cents, :tax_cents, keyword_init: true)
  def initialize(*)
    super
    freeze
  end

Memoizing a Pricing Breakdown as an Immutable Value Object in Rails

rails memoization value-object
by codesnips 3 tabs
rust 
use std::fmt;

#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum OrderState {
    Pending,
    Paid,

Type-State Order Lifecycle Machine With Compile-Time Transition Safety in Rust

state-machine enums type-state
by codesnips 3 tabs
python 
from datetime import datetime, timedelta, timezone

from jose import jwt, JWTError
from jose.exceptions import ExpiredSignatureError

SECRET_KEY = "change-me-in-production"

FastAPI JWT Authentication with Access/Refresh Tokens and a Verification Dependency

fastapi jwt authentication
by codesnips 3 tabs
java 
package com.example.catalog.web;

import com.example.catalog.domain.Product;
import java.math.BigDecimal;

public record ProductResponse(

Paginated Product Search Endpoint with Spring Data JPA Specifications

spring-boot spring-data-jpa pagination
by codesnips 4 tabs
python 
from django.conf import settings
from django.db.models.signals import post_save
from django.dispatch import receiver

from .models import EmailOutbox

Sending Welcome Emails via a Django post_save Signal and Outbox Worker

django signals email
by codesnips 4 tabs
go 
package bank

import "errors"

var ErrVersionConflict = errors.New("optimistic lock: version conflict")
var ErrInsufficientFunds = errors.New("insufficient funds")

Optimistic Locking in Go With a Version Column on UPDATE

optimistic-locking concurrency postgres
by codesnips 3 tabs
rust 
use std::fmt;
use std::hash::{Hash, Hasher};
use std::marker::PhantomData;
use uuid::Uuid;

pub struct Id<T> {

Type-Safe Entity IDs in Rust with a Zero-Cost Id<T> Newtype

rust newtype type-safety
by codesnips 3 tabs
python 
import queue
import time
from dataclasses import dataclass, field, replace
from typing import Any, Dict, Tuple

In-Process Threaded Background Job Queue for Sending Emails Without Redis

background-jobs threading queue
by codesnips 4 tabs
typescript 
import { z } from 'zod';

export const signupSchema = z
  .object({
    email: z.string().min(1, 'Email is required').email('Enter a valid email'),
    username: z

Field-Level Signup Validation with Zod and a Typed useZodForm Hook

react zod forms
by codesnips 3 tabs
rust 
use std::time::Duration;
use rand::Rng;

#[derive(Clone, Debug)]
pub struct BackoffPolicy {
    pub base_delay: Duration,

Exponential Backoff With Jitter for Retrying Fallible Async Operations in Rust

rust tokio async
by codesnips 3 tabs
typescript 
import { useEffect, useState } from "react";

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

  useEffect(() => {

Debounced Search Box With AbortController to Cancel Stale Fetches in React

react hooks debounce
by codesnips 3 tabs
ruby 
class AddressForm
  include ActiveModel::Model
  include ActiveModel::Attributes

  attribute :line1, :string
  attribute :line2, :string

Rails Nested Address Form Object With Aggregated ActiveModel Errors

rails activemodel form-object
by codesnips 3 tabs