codesnips

validation

typescript 
export class AppError extends Error {
  public readonly statusCode: number;
  public readonly code: string;
  public readonly isOperational: boolean;

  constructor(message: string, statusCode = 500, code = 'INTERNAL_ERROR', isOperational = true) {

Backend: normalize errors with a single Express handler

express error-handling typescript
by codesnips 4 tabs
java 
package com.example.demo.dto;

import com.example.demo.validation.UniqueEmail;
import jakarta.validation.constraints.*;
import lombok.Data;

Validation with Bean Validation API

java validation bean-validation
by David Kumar 3 tabs
python 
from django.db import models
from django.core.exceptions import ValidationError
from django.utils import timezone


class Event(models.Model):

Django model validation with clean method

django python models
by Priya Sharma 1 tab
ruby 
class SignupsController < ApplicationController
  def new
    @user = User.new
  end

  def create

Inline form validation feedback via Turbo Streams

rails hotwire turbo
by codesnips 4 tabs
go 
package appconfig

import (
	"flag"
	"io"
	"os"

Parsing and Validating CLI Flags into a Typed Config Struct in Go

cli flags configuration
by codesnips 3 tabs
python 
from typing import Optional
from pydantic import BaseModel, EmailStr, Field, field_validator, model_validator


class CreateUserRequest(BaseModel):
    model_config = {"extra": "forbid"}

Validating JSON Payloads with Pydantic v2 and Returning Field-Level Errors in FastAPI

fastapi pydantic validation
by codesnips 3 tabs
ruby 
allowed_types = ['image/png', 'image/jpeg', 'application/pdf']
uploaded = params.require(:document)

raise ActionController::BadRequest, 'file too large' if uploaded.size > 10.megabytes
raise ActionController::BadRequest, 'type not allowed' unless allowed_types.include?(uploaded.content_type)

Hardening file uploads with MIME checks and storage isolation

file-uploads validation malware
by Kai Nakamura 1 tab
java 
package com.example.auth.dto;

import jakarta.validation.constraints.Email;
import jakarta.validation.constraints.NotBlank;
import jakarta.validation.constraints.Pattern;
import jakarta.validation.constraints.Size;

Collect Bean Validation Field Errors in a Spring Boot Signup Endpoint

spring-boot bean-validation jakarta-validation
by codesnips 3 tabs
java 
package com.shop.orders;

import jakarta.persistence.*;
import java.math.BigDecimal;
import java.time.Instant;
import java.util.ArrayList;

Mapping a JPA Entity to a Response DTO with MapStruct in Spring Boot

spring-boot jpa mapstruct
by codesnips 4 tabs
php 
<?php

namespace App\Dto;

use Symfony\Component\HttpFoundation\File\UploadedFile;
use Symfony\Component\Validator\Constraints as Assert;

Symfony Avatar Upload: Constrained Form Type, Image Validation, and an Uploader Service

symfony forms validation
by codesnips 4 tabs
typescript 
export type ErrorCode =
  | 'VALIDATION'
  | 'UNAUTHENTICATED'
  | 'FORBIDDEN'
  | 'NOT_FOUND'
  | 'CONFLICT'

API error shape that frontend can rely on

typescript express react
by codesnips 4 tabs
ruby 
class Problem
  DEFAULT_TYPE = "https://api.example.com/problems/about:blank".freeze

  attr_reader :type, :title, :status, :detail, :instance, :extensions

  def initialize(status:, title:, detail: nil, type: nil, instance: nil, extensions: {})

API Error Handling with Problem Details (RFC7807-ish)

rails api error-handling
by codesnips 3 tabs