skhema

JSON Schema utility collection

Installation

Install skhema by running:

$ npm install --save skhema

Documentation

• skhema
  • .SchemaMismatch : Error
  • .IncompatibleSchemas : Error
  • .restrictSchema(subjectSchema, restrictingSchema) ⇒ Object
  • .scoreMatch(schema, object) ⇒ Number
  • .match(schema, object, [options]) ⇒ Object
  • .isValid(schema, object, [options]) ⇒ Boolean
  • .validate(schema, object, [options])
  • .merge(schemas) ⇒ Object
  • .normaliseRequires(schema) ⇒ Object
  • .filter(schema, object, [options]) ⇒ Object | Null

skhema.SchemaMismatch : Error

Kind: static property of skhema
Summary: Schema mismatch error
Access: public

skhema.IncompatibleSchemas : Error

Kind: static property of skhema
Summary: Incompatible schemas error
Access: public

skhema.restrictSchema(subjectSchema, restrictingSchema) ⇒ Object

Removes values from a subject schema so that a value that matches the resulting schema will also validate against the restricting schema.

Kind: static method of skhema
Summary: Restrict a schema using another schema
Returns: Object - restricted schema
Access: public

Param	Type	Description
subjectSchema	Object	schema
restrictingSchema	Object	schema

Example

const result = skhema.restrictSchema({
	 type: 'object',
	 properties: {
		 foo: {
			 type: 'number'
		 },
		 bar: {
			 type: 'string'
		 }
	 },
	 required: [ 'foo' ]
}, {
	 type: 'object',
	 properties: {
		 foo: {
			 type: 'number'
		 }
	 },
	 additionalProperties: false,
	 required: [ 'foo' ]
})

console.log(result)
> {
>   type: 'object',
>   properties: {
>  	 foo: {
>  		 type: 'number'
>  	 },
>   },
>   additionalProperties: false,
>   required: [ 'foo' ]
> }

skhema.scoreMatch(schema, object) ⇒ Number

Score a matching object and schema based on specificity. Only works with values that are valid against the provided schema

Kind: static method of skhema
Summary: Score a schema match by specificity
Returns: Number - score
Access: public

Param	Type	Description
schema	Object	JSON schema
object	Object	object

Example

const score = skhema.scoreMatch({
	 type: 'object'
}, {
	 foo: 'bar'
})

console.log(result) // -> 1

skhema.match(schema, object, [options]) ⇒ Object

Kind: static method of skhema
Summary: Match an object against a schema
Returns: Object - results
Access: public

Param	Type	Default	Description
schema	Object		JSON schema
object	Object		object
[options]	Object		options
[options.schemaOnly]	Boolean	false	Only validate the schema

Example

const results = skhema.match({
	 type: 'object'
}, {
	 foo: 'bar'
})

if (!results.valid) {
	 for (const error of results.errors) {
		 console.error(error)
	 }
}

skhema.isValid(schema, object, [options]) ⇒ Boolean

This is a shorthand function for .match() which can be used if the caller is not interested in the actual error messages.

Kind: static method of skhema
Summary: Check if an object matches a schema
Returns: Boolean - whether the object matches the schema
Access: public

Param	Type	Default	Description
schema	Object		JSON schema
object	Object		object
[options]	Object		options
[options.schemaOnly]	Boolean	false	Only validate the schema

Example

const isValid = skhema.isValid({
	 type: 'object'
}, {
	 foo: 'bar'
})

if (isValid) {
	 console.log('The object is valid')
}

skhema.validate(schema, object, [options])

The .validate() method will throw if the provided schema isn't valid or if the object doesn't validate against the schema. If you just want to validate a schema, you use the schemaOnly option.

Kind: static method of skhema
Summary: Validate an object and schema and throw if invalid
Access: public

Param	Type	Default	Description
schema	Object		JSON schema
object	Object		object
[options]	Object		options
[options.schemaOnly]	Boolean	false	Only validate the schema

Example

skhema.validate({
	 type: 'object'
}, {
	 foo: 'bar'
})

skhema.merge(schemas) ⇒ Object

Kind: static method of skhema
Summary: Merge two or more JSON Schemas
Returns: Object - merged JSON Schema
Access: public

Param	Type	Description
schemas	Array.<Object>	a set of JSON Schemas

Example

const result = skhema.merge([
	 {
		 type: 'string',
		 maxLength: 5,
		 minLength: 2
	 },
	 {
		 type: 'string',
		 maxLength: 3
	 }
])

console.log(result)
> {
>	 type: 'string',
>	 maxLength: 3,
>	 minLength: 2
> }

skhema.normaliseRequires(schema) ⇒ Object

Kind: static method of skhema
Summary: Set fields on a schema which are required but do not appear in properties
Returns: Object - mutated schema
Access: public

Param	Type	Description
schema	Object	schema

Example

const schema = skhema.normaliseRequires({
	 type: 'object',
	 properties: {},
	 required: [ 'foo' ]
})

console.log(schema.properties)
> { foo: { additionalProperties: false } }

skhema.filter(schema, object, [options]) ⇒ Object | Null

Kind: static method of skhema
Summary: Filter an object based on a schema
Returns: Object | Null - filtered object
Access: public

Param	Type	Default	Description
schema	Object		schema
object	Object		object
[options]	Object		options
[options.schemaOnly]	Boolean	false	Only validate the schema

Example

const result = skhema.filter({
	 type: 'object',
	 properties: {
		 foo: {
			 type: 'number'
		 }
	 },
	 required: [ 'foo' ]
}, {
	 foo: 1,
	 bar: 2
})

console.log(result)
> {
>	 foo: 1
> }

Tests

Run the test suite by doing:

$ npm test

Contribute

We're looking forward to support more operating systems. Please raise an issue or even better, send a PR to increase support!

• Issue Tracker: github.com/resin-io-modules/skhema/issues
• Source Code: github.com/resin-io-modules/skhema

Before submitting a PR, please make sure that you include tests, and that the linter runs without any warning:

npm run lint

Support

If you're having any problem, please raise an issue on GitHub.

License

The project is licensed under the Apache 2.0 license.