@sidvind/better-ajv-errors

What is @sidvind/better-ajv-errors?

@sidvind/better-ajv-errors is a utility package designed to provide more human-readable error messages when using the Ajv JSON schema validator. It enhances the default error messages provided by Ajv, making it easier to understand and debug schema validation issues.

What are @sidvind/better-ajv-errors's main functionalities?

Human-readable error messages

This feature allows you to generate more readable error messages from Ajv validation errors. The code sample demonstrates how to use @sidvind/better-ajv-errors to enhance the error messages for a simple JSON schema validation.

const Ajv = require('ajv');
const betterAjvErrors = require('@sidvind/better-ajv-errors');

const ajv = new Ajv();
const schema = {
  type: 'object',
  properties: {
    name: { type: 'string' },
    age: { type: 'integer' }
  },
  required: ['name', 'age']
};

const data = {
  name: 'John Doe',
  age: 'twenty-five'
};

const validate = ajv.compile(schema);
const valid = validate(data);

if (!valid) {
  const output = betterAjvErrors(schema, data, validate.errors, { format: 'js' });
  console.log(output);
}

Other packages similar to @sidvind/better-ajv-errors

ajv-errors

ajv-errors is an Ajv plugin that allows for custom error messages in JSON schema validation. It provides a way to define custom error messages directly in the schema, which can be more flexible but requires more setup compared to @sidvind/better-ajv-errors.

ajv-i18n

ajv-i18n is another Ajv plugin that provides internationalization (i18n) for Ajv error messages. It translates Ajv error messages into different languages, which can be useful for applications that need to support multiple languages. Unlike @sidvind/better-ajv-errors, it focuses on translation rather than improving readability.

README

JSON Schema validation for Human 👨‍🎤

Main goal of this library is to provide relevant error messages like the following:

Fork

This fork removes the legacy build and thus drops dependencies such as core-js and @babel/runtime which is not needed on modern installations.

• Node 12 and later supports the modern build and according to the release plan node 10 was EOL at 2021-04-30.
• Earlier versions is already EOL and not supported. Anyone using it should update instead.

The following PRs from upstream are merged:

• PR-85: fix: enumeration in anyOf
• PR-67: fix(typings): Correct TypeScript type definition (superseeded by upstream fix)
• PR-70: Drop legacy build and dependecy on polyfills (dropped in favour of esbuild)

The following PRs has been merged upstream:

• PR-84: feat: support json option to get accurate line/column listings
• PR-92: feat: ajv 8 support

Installation

$ npm i @sidvind/better-ajv-errors

Also make sure that you installed ajv package to validate data against JSON schemas.

Usage

First, you need to validate your payload with ajv. If it's invalid then you can pass validate.errors object into better-ajv-errors.

import Ajv from 'ajv';
import betterAjvErrors from '@sidvind/better-ajv-errors';
// const Ajv = require('ajv');
// const betterAjvErrors = require('@sidvind/better-ajv-errors').default;
// Or
// const { default: betterAjvErrors } = require('@sidvid/better-ajv-errors');

// You need to pass `{ jsonPointers: true }` for older versions of ajv
const ajv = new Ajv();

// Load schema and data
const schema = ...;
const data = ...;

const validate = ajv.compile(schema);
const valid = validate(data);

if (!valid) {
  const output = betterAjvErrors(schema, data, validate.errors);
  console.log(output);
}

API

betterAjvErrors(schema, data, errors, [options])

Returns formatted validation error to print in console. See options.format for further details.

schema

Type: Object

The JSON Schema you used for validation with ajv

data

Type: Object

The JSON payload you validate against using ajv

errors

Type: Array

Array of ajv validation errors

options

Type: Object

format

Type: string
Default: cli
Values: cli js

Use default cli output format if you want to print beautiful validation errors like following:

Or, use js if you are planning to use this with some API. Your output will look like following:

[
  {
    start: { line: 6, column: 15, offset: 70 },
    end: { line: 6, column: 26, offset: 81 },
    error:
      '/content/0/type should be equal to one of the allowed values: panel, paragraph, ...',
    suggestion: 'Did you mean paragraph?',
  },
];

indent

Type: number null
Default: null

If you have an unindented JSON payload and you want the error output indented.

This option have no effect when using the json option.

json

Type: string null
Default: null

Raw JSON payload used when formatting codeframe. Gives accurate line and column listings.

Changelog

4.0.0

Major Changes

• d00a368: require nodejs v18 or later
• 704e0dc: require ajv v7 or later