mgl-validate

data object validation

mgl-validate is a library for validating any variable type, including objects, arrays and primitives, as well as mixed type definitions.

Moreover, mgl-validate enables the programmer to verify the validity of complex & deeply nested object structures. The library features defining validation schemas to be used as references, hence facilitating shared and reusable definitions upon which complex and possibly nested validation schemas can be built.

Schemas are compiled at time of definition to keep performance penalties of actual validations at a minimum.

Stability: 3 - Stable

Table of Contents

• Schema
• API
• Tests
• License
• ChangeLog

Testimonials

I really like the notion of adding a schema and referencing it in others - that's just super-cool

Example

var registry = require('mgl-validate')({
  breakOnError: true
});
 
try {
  // create a nested schema
  registry.addSchema({
    id: 'doc',
    type: 'object',
    properties: {
      ref: {
        id: 'uuid',
        type: 'string',
        pattern: '[a-f\\d]{8}(-[a-f\\d]{4}){3}-[a-f\\d]{12}'
      }
    }
  });
} catch (err) {
  return console.log(err.message);
}
 
var errors;
 
// validate against 'doc'
errors = registry.test('doc', {ref: 'THIS-IS-NOT-AN-UUID'});
if (errors) {
  console.log(errors);
}
 
// ... or validate directly against 'uuid'
errors = registry.test('uuid', 'THIS-IS-NOT-AN-UUID');
if (errors) {
  console.log(errors);
}

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Types

• null
• boolean
• number
• integer - validates as number too
• string
• array
• object
• buffer
• function
• mixed

Schema

See tests for examples covering all use cases.

The options are processed in the following order; type optional value min < max < enum < pattern properties, where A < B means that B is only tested when A didn't fail.

properties

• {?string=} id - The schema id, when given the schema can be referenced
• {string} type - The data type; See Types
• {?number=} depth - Absolute nesting limit for validated data, defaults to 10
• {?boolean=} optional - When true, the value may be undefined
• {?*=} default - A default value, implies optional: true
• {?string=} pattern - An encoded regular-expression for string validation
• {?string=} flags - Regular-expression flags
• {?number=} min - Minimum number of chars, elements, properties, arguments
• {?number=} max - Maximum number of chars, elements, properties, arguments
• {?Object<string, (Object|string)>=} properties - A map with schemas for each property of an object
• {?boolean=} allowUnknownProperties - When true, an object may contain properties that don't have a schema
• {?(Array|Object|string)=} enum - Validate values against given primitives and/or schemas
• {?boolean=} ordered - When true, an array is matched against enum in order
• {?boolean=} allowNullValue - When true, the affected schema's value may be null

enum

Validate values against given values and/or schemas.

NOTE: The most likely values should be placed at the top of the enum array to improve validation performance.

Types: number, integer, string, array, mixed

Primitives

Primitive data types can be validated against a list of static values of their own type;

{ type: 'number', // or 'integer' or 'string'
  enum: [1, 2, 3]
}

type: array

Arrays support multiple combinations for enum;

... a single schema, either as reference ($id:<name>) or object. All elements in the array now have to comply to the given schema.

{ type: 'array',
  enum: '$id:uuid'
}

... an array of schemas and/or primitives. Any element in the array has to comply to any of the supplied schemas. When ordered: true, the elements of the array have to comply to the given schemas in order.

{ type: 'array',
  ordered: true,
  enum: [
    '$id:uuid',
    false,
    {type: 'integer'}
  ]
}

In the above example the 2nd, 5th, 8th, ... element of any array has to be false in order to pass the test

Validation restarts at the first element of the given enum if the number of elements t.b. validated exceeds the given schemas. This behaviour can be further controlled with the min and max options.

type: mixed

enum for type: mixed works exactly like for type: array with an array of schemas and/or primitives, but in respect to a single value.

properties

An object with properties where each value is a primitive value, schema object or reference.

Types: object, function

{ type: 'object',
  properties: {
    xyz: {
      type: 'number'
    },
    abc: '$id:other',     // has to match "other" schema
    wtf: 'abc',           // primitive equals match
    ...
  }
}

wildcard

Types: object

{ type: 'object',
  properties: {
    '*': {                // all unknown properties have to match this schema
      type: 'string',
      ...
    },
    ...
  }
}

min & max

A number that describes the minimum ...

• value for a number or an integer
• length for a string
• length for an array
• number of arguments for a function
• number of properties on an object

Types: number, integer, string, array, object, function

Note: When min fails, the test for max is omitted for logical reasons.

pattern

A string to be used for new RegExp().

Types: string

flags

Types: string

optional

When true the value may be undefined, type violations other than undefined produce an error.

Types: ALL

default

Works ONLY for object properties!

Apply a default value if undefined.

Types: number, integer, string, array, function

allowUnknownProperties

Allows an object to have properties not specified in the schema. Defaults to true for function and to false for object.

Types: object, function

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API

Class: Registry

new Registry(opt_options)

• {?Object=} opt_options
  • {?boolean=} breakOnError - defaults to false
  • {?number=} depth - Global nesting limit, defaults to 10. Can be overridden by each schema

registry.breakOnError

registry.getSchemas()

registry.addSchema(definition)

registry.removeSchema(schema)

registry.test(schema, data);

See schema.test().

Class: Schema

new Schema(registry, definition)

schema.test(data)

Validate given data, returns validation errors as array, null otherwise.

An annotated example;

[
  [<pathToValue>, <expectedType>, <reason>, <offendingValue>],
 
  // property b of object a is undefined
  ['a', 'object', 'undefined', 'b'],
 
  // property c of object a is not of type string
  ['a.c', 'string', 'type', 2],
 
  // property e of the 1st element of the array at property d of object a is too small
  ['a.d.0.e', 'number', 'min', -1],
  ...
]

schema.typeOf(value)

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Tests

npm test
firefox coverage/lcov-report/index.html

Coverage

Statements   : 99.37% ( 317/319 )
Branches     : 97.74% ( 260/266 )
Functions    : 100% ( 21/21 )
Lines        : 99.37% ( 317/319 )

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License

(The MIT license)

Copyright (c) 2015 Magora Group GmbH, Austria (www.magora.at)

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

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