<h1 align="center">
  <img width="570" src="media/logo.png" alt="better-ajv-errors">
  <br>
</h1>

> JSON Schema validation for Human 👨‍🎤

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

<p align="center">
  <img src="media/screenshot.svg">
</p>

## Differences from `better-ajv-errors`

- Only targets current Node LTS releases.
- AJV 8 support.
- Default errors stack the error message at the top of the location instead of the bottom.
  - This helps eliminate long blocks of `^^^^^^` pointers.
- Addition of a `colorize` option for disabling colorization in `format: cli` output.
- Up-to-date dependencies.

## Installation

```bash
$ npm i better-ajv-errors
```

Also make sure that you installed [ajv](https://www.npmjs.com/package/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`.

```js
import Ajv from 'ajv';
import betterAjvErrors from 'better-ajv-errors';
// const Ajv = require('ajv');
// const betterAjvErrors = require('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`](#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](https://github.com/epoberezkin/ajv#validation-errors)

#### options

Type: `Object`

##### colorize

Type: `boolean`
Default: `true`

When disabled, if you are outputting `cli` formatting it will be without colorized or styled content.

##### format

Type: `string`
Default: `cli`
Values: `cli` `js`

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

<img width="620" src="media/screenshot.svg">

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

```javascript
[
  {
    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.