codesnips
python 
import os
import uuid

from flask import Blueprint, current_app, jsonify, request
from werkzeug.exceptions import RequestEntityTooLarge

Streaming Large Multipart File Uploads to Disk in Flask Without Buffering

flask werkzeug streaming
by codesnips 3 tabs
javascript 
export const initialCart = { items: {} };

export function cartReducer(state, action) {
  switch (action.type) {
    case 'ADD_ITEM': {
      const { product, qty = 1 } = action;

Persist and Hydrate a Shopping Cart with useReducer and localStorage

react hooks usereducer
by codesnips 3 tabs
python 
import threading
from contextlib import contextmanager

_state = threading.local()

Per-Tenant Data Isolation in Django with a Thread-Local Current Tenant Manager

django multi-tenancy orm
by codesnips 4 tabs
java 
package com.example.payments;

import io.micrometer.core.instrument.Counter;
import io.micrometer.core.instrument.MeterRegistry;
import io.micrometer.core.instrument.Timer;
import org.springframework.stereotype.Service;

Instrumenting a Spring Service with Micrometer Counters, Timers, and @Timed

spring-boot micrometer metrics
by codesnips 3 tabs
go 
package session

import (
	"crypto/hmac"
	"crypto/sha256"
	"encoding/base64"

Stateless Session Cookies Signed and Verified With HMAC in Go

go security cookies
by codesnips 3 tabs
javascript 
const DEFAULTS = {
  baseDelay: 300,
  maxDelay: 8000,
  factor: 2,
  jitter: 0.5,
};

Retry Failed React Mutations with Exponential Backoff and a Status Component

react hooks retry
by codesnips 4 tabs
python 
from __future__ import annotations

from dataclasses import dataclass, field
from decimal import Decimal, ROUND_HALF_UP
from typing import Optional, Protocol

Composable Order Discount Pipeline With Rule Objects in Python

pipeline strategy-pattern discounts
by codesnips 3 tabs
typescript 
import { Exclude, Expose } from 'class-transformer';

export class User {
  id: string;

  firstName: string;

Hide Sensitive Fields in NestJS Responses with class-transformer and ClassSerializerInterceptor

nestjs class-transformer serialization
by codesnips 3 tabs
ruby 
class DiscountCode < ApplicationRecord
  has_many :redemptions, dependent: :destroy

  enum discount_type: { percentage: 0, fixed: 1 }

  validates :code, presence: true, uniqueness: { case_sensitive: false }

Redeem Discount Codes in Rails with a Locking Service and Row-Level Guards

rails activerecord discounts
by codesnips 4 tabs
java 
public class PayloadLimitFilter extends OncePerRequestFilter {

    private final long maxBytes;
    private final Set<String> allowedTypes;

    public PayloadLimitFilter(long maxBytes, Set<String> allowedTypes) {

Enforce Request Payload Size and Content-Type with a Servlet Filter and Controller Guard

spring-boot servlet-filter validation
by codesnips 4 tabs
python 
import time
import uuid
from dataclasses import dataclass

import redis

Sliding-Window Per-User Rate Limiting With Redis and a Flask Decorator

rate-limiting redis flask
by codesnips 3 tabs
rust 
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct Currency {
    pub code: &'static str,
    pub symbol: &'static str,
    pub exponent: u32,
}

Locale-Aware Money Formatting With Minor Units in Rust

rust money currency
by codesnips 3 tabs