422 Unprocessable Content

The request was perfectly formatted, but contained semantic errors. E.g. providing an email address that isn’t valid, but sending it correctly.

When and Why to Use It

Use this for validation errors. E.g., the JSON was perfectly valid, but the ‘age’ field was set to -50. Use 422 to say ‘I understood it, but the data is semantically wrong’.

Usage Examples

Shokupan (Functional)

import { HttpException, post } from 'shokupan';

export const updateProfile = post('/profile', (req) => {
    if (req.body.password && req.body.password.length < 8) {
        throw new HttpException('Password must be at least 8 characters', 422);
    }

    // ... update profile
});

Shokupan (Controller)

import { Controller, Post, Body, HttpException } from 'shokupan';

@Controller('/api')
export class ProfileController {
    @Post('/profile')
    updateProfile(@Body() body: any) {
        if (body.password && body.password.length < 8) {
            throw new HttpException('Password must be at least 8 characters', 422);
        }

        // ... update profile
    }
}

Express

import express from 'express';
const app = express();

app.post('/profile', (req, res) => {
    if (req.body.password && req.body.password.length < 8) {
        return res.status(422).json({ error: 'Password must be at least 8 characters' });
    }

    // ... update profile
});

Nest

import { Controller, Post, Body, UnprocessableEntityException } from '@nestjs/common';

@Controller('profile')
export class ProfileController {
  @Post()
  updateProfile(@Body() body: any) {
    if (body.password && body.password.length < 8) {
      throw new UnprocessableEntityException('Password must be at least 8 characters');
    }

    // ... update profile
  }
}

Koa

import Koa from 'koa';
const app = new Koa();

app.use(async ctx => {
  if (ctx.path === '/profile' && ctx.method === 'POST') {
    const body = ctx.request.body;

    if (body && body.password && body.password.length < 8) {
      ctx.status = 422;
      ctx.body = { error: 'Password must be at least 8 characters' };
      return;
    }

    // ... update profile
  }
});