schema-utils
Webpack Schema Validation Utilities
Validates options objects against a JSON Schema and
displays the output beautifully.

Requirements
This module requires a minimum of Node v6.9.0 and Webpack v4.0.0.
Getting Started
To begin, you'll need to install schema-utils:
$ npm install @webpack-contrib/schema-utils --save-dev
API
When using the API directly, the main entry point is the serve function, which
is the default export of the module.
const validate = require('@webpack-contrib/schema-utils');
const schema = require('path/to/schema.json');
const target = { ... }; // the options object to validate
const name = '...'; // the load or plugin name validate() is being used in
validate({ name, schema, target });
serve(options)
Returns true if validation succeeded, false validation failed and options
allow the function to return a value. (see options below).
options
Type: Object
Options for initializing and controlling the server provided. The option names
listed below belong to the options object.
exit
Type: Boolean
Default: false
If true, will instruct the validator to end the process with an error code of
1.
log
Type: Boolean
Default: false
If true, will instruct the validator to log the results of the validation (in
the event of a failure) in a
webpack-style log output. This
is typically used with throw: false.

name
Type: String
Default: undefined
Required
A String specifying the name of the loader or plugin utilizing the validator.
schema
Type: String|Object
Default: undefined
Required
A String specifying the filesystem path to the schema used for validation.
Alternatively, you may specify an object containing the JSON-parsed schema.
target
Type: Object
Default: undefined
Required
An Object containing the options to validate against the specified schema.
throw
Type: Boolean
Default: true
By default the validator will throw an error and display validation results upon
failure. If this option is set to false, the validator will not throw an error.
This is typically used in situations where a return value of false for
validate() is sufficient, a stack trace is uneeded, or when
webpack-style log output is
preferred.

Examples
Below is a basic example of how this validator might be used:
# schema.json
{
"type": "object",
"properties": {
"name": {
"type": "string"
},
"test": {
"anyOf": [
{ "type": "array" },
{ "type": "string" },
{ "instanceof": "RegExp" }
]
},
"transform": {
"instanceof": "Function"
},
"sourceMap": {
"type": "boolean"
}
},
"additionalProperties": false
}
Use in a Loader
const { getOptions } = require('loader-utils');
const validate = require('@webpack-contrib/schema-utils');
import schema from 'path/to/schema.json'
function loader (src, map) {
const options = getOptions(this) || {};
validate({ name: 'Loader Name', schema, target: options });
// Code...
}
Use in a Plugin
const validate = require('@webpack-contrib/schema-utils');
const schema = require('path/to/schema.json');
class Plugin {
constructor (options) {
validate({ name: 'Plugin Name', schema, target: options });
this.options = options;
}
apply (compiler) {
// Code...
}
}