awesome-ajv-errors pretty-prints ajv errors
It has a gorgeous human-understandable output, predicts human errors and suggests fixes.
- Since version 2;
- This is a pure ESM package. It requires Node 12.20 and cannot be used from CommonJS.
- Ajv 6, 7 and 8 are supported.
- Since version 3;
- This package can be used in browsers without special hacks. It will by default not pretty-print codeframes or use colors. If you want this, you have two options:
- Either import from
awesome-ajv-errors/node
explicitly (if you have e.g. webpack DefinePlugin configured to hack around missing things likeprocess is not defined
), or - Import from
awesome-ajv-errors/try-styled
which has a promise-basedprettify
function (prettifyTryStyled
) or a promise which will eventually resolve to a synchronous function (styledPrettify
). - Both of these will fallback to non-colored non-codeframe output if e.g. loading
@babel/code-frame
failed. This will likely be entirely resolved once Babel 8 is released; then awesome output will by default work in browsers too.
- Either import from
- This package can be used in browsers without special hacks. It will by default not pretty-print codeframes or use colors. If you want this, you have two options:
- Since version 4;
- package.json exports field is not support well by e.g. Jest, so v4 reverts the v3 exports.
- Until the exports field get better support, the official way to import will now be from:
awesome-ajv-errors
for auto-detecting node vs browserawesome-ajv-errors/dist/index-node.js
orawesome-ajv-errors/dist/index-browser.js
for explicit importing depending on environmentawesome-ajv-errors/dist/index-try-styled.js
for dynamic trying to load color support (e.g. in browsers)
- Since version 5;
- Re-introduced package exports.
- Replaced
@babel/code-frame
withawesome-code-frame
which uses later versions of upstream dependencies - works out-of-the-box in browsers now. - It will by default pretty-print codeframes and use colors, including in browsers that supports it. This will look bad in the browser window, but good in the developer tools.
- Import from
awesome-ajv-errors/plain
explicitly to have colors and code frame output disabled, or use the options toprettify()
to disable per call.
- Import from
- Now using the latest chalk, which means it requires support for package imports. If this causes problems in Jest for you, see this issue for help.
Suggest similar properties
JSON Schema and data
schema.json
{
"title": "Second-level two similar properties",
"type": "object",
"properties": {
"foo": {
"type": "object",
"properties": {
"bar": {},
"bak": {}
},
"additionalProperties": false
}
}
}
data.json
{
"foo": {
"bar": "42",
"baz": "33"
}
}
Suggests multiple valid property names
JSON Schema and data
schema.json
{
"title": "Second-level three similar properties",
"type": "object",
"properties": {
"foo": {
"type": "object",
"properties": {
"bar": {},
"bak": {},
"bam": {}
},
"additionalProperties": false
}
}
}
data.json
{
"foo": {
"bar": "42",
"baz": "33"
}
}
Suggests the valid value type when mistaken
JSON Schema and data
schema.json
{
"title": "One option (number to string)",
"type": "object",
"properties": {
"foo": {
"anyOf": [
{
"type": "string"
}
]
}
}
}
data.json
{
"foo": 42
}
Suggests the valid value type when mistaken
JSON Schema and data
schema.json
{
"title": "One option (string to number)",
"type": "object",
"properties": {
"foo": {
"anyOf": [
{
"type": "number"
}
]
}
}
}
data.json
{
"foo": "42"
}
When the type mismatch, and one type is much "better" than the rest (as in probably the right solution), it will be suggested for conversion
JSON Schema and data
schema.json
{
"title": "Two options",
"type": "object",
"properties": {
"foo": {
"anyOf": [
{
"type": "string"
},
{
"type": "boolean"
}
]
}
}
}
data.json
{
"foo": 42
}
JSON Schema and data
schema.json
{
"title": "Three options",
"type": "object",
"properties": {
"foo": {
"anyOf": [
{
"type": "string"
},
{
"type": "boolean"
},
{
"type": "null"
}
]
}
}
}
data.json
{
"foo": 42
}
JSON Schema and data
schema.json
{
"title": "2 too few",
"type": "object",
"properties": {
"foo": {
"type": "array",
"minItems": 3
}
}
}
data.json
{
"foo": [
1
]
}
JSON Schema and data
schema.json
{
"title": "Less than or equal to",
"type": "object",
"properties": {
"foo": {
"type": "number",
"maximum": 17
}
}
}
data.json
{
"foo": 42
}
JSON Schema and data
schema.json
{
"title": "One value of same type",
"type": "object",
"properties": {
"foo": {
"enum": [
41
]
}
}
}
data.json
{
"foo": 42
}
JSON Schema and data
schema.json
{
"title": "Two options (one of different type)",
"type": "object",
"properties": {
"foo": {
"enum": [
41,
"42"
]
}
}
}
data.json
{
"foo": 42
}
JSON Schema and data
schema.json
{
"title": "Four options (one of different type)",
"type": "object",
"properties": {
"foo": {
"enum": [
"falso",
"other",
"False",
false
]
}
}
}
data.json
{
"foo": "false"
}
JSON Schema and data
schema.json
{
"title": "time invalid",
"type": "object",
"properties": {
"foo": {
"type": "string",
"format": "time"
}
}
}
data.json
{
"foo": "11:22:334"
}
JSON Schema and data
schema.json
{
"title": "email invalid",
"type": "object",
"properties": {
"foo": {
"type": "string",
"format": "email"
}
}
}
data.json
{
"foo": "quite@invalid@email.com"
}
JSON Schema and data
schema.json
{
"title": "if-then on first-level object",
"properties": {
"foo": {
"if": {
"properties": {
"firstName": {
"const": true
}
}
},
"then": {
"required": [
"lastName"
]
}
}
}
}
data.json
{
"foo": {
"firstName": true
}
}
JSON Schema and data
schema.json
{
"title": "Multiple of",
"type": "object",
"properties": {
"foo": {
"type": "number",
"multipleOf": 4
}
}
}
data.json
{
"foo": 17
}
JSON Schema and data
schema.json
{
"title": "Root-level required",
"type": "object",
"properties": {
"foo": {}
},
"required": [
"foo"
]
}
data.json
{
"bar": 42
}
Import the ajv
package, and prettify
from awesome-ajv-errors
:
import * as Ajv from 'ajv'
import { prettify } from 'awesome-ajv-errors'
Create an ajv instance and validate objects:
const ajv = new Ajv( { allErrors: true } ); // allErrors is optional
let data, schema; // Get the JSON schema and the JSON data from somewhere
const validate = ajv.compile( schema );
validate( data );
Now, the validation error is stored on the validate
function. Use prettify
to pretty-print the errors, and provide the data so that awesome-ajv-errors can suggest fixes:
console.log( prettify( validate, { data } ) );
Instead of auto-detecting based on the platform (Node.js or a browser), you can turn on/off colors, location printing (the json-snippet of the error) and whether to print big ascii numbers to the left of each error, if there are more than one error.
With the options object containing data
provided to prettify
you can include colors
, location
and bigNumbers
as booleans, to override the defaults.
Turning colors explicitly on will only enable colors if it's detected to be supported by the platform, but turning them off will always output non-colored text.
Turning location on will also only enable the location printing if colors are detected to be supported by the underlying platform (this is a limitation in the current @babel/code-frame
and will likely be resolved in Babel 8).
bigNumbers
will only be enabled if location printing is enabled, but can be explicitly turned off.
Example:
const colors = false;
const location = false;
const explanation = prettify( validate, { data, colors, location } );