typetree

Object validation using a definition laid out as a type-tree.

Install

npm install typetree

Usage

const {validateObject} = require('typetree')

Defining a typetree

Typetree definitions can be JavaScript built-in objects

Boolean
Number
String
Object

or a literal values such as null, "string literal", 12 (number), undefined (indicates that the values can be ommited)

Here's a comprehesive sample (validation object for a company):

var validObject = {
    id: Number,
    name: String,
    address: {
        city: String,
        // optional values
        country: ['EE', 'FI', 'SE']
    },
    // an array of objects
    branches: [
        {
            name: String,
            subId: Number
        }
    ],
    // either true, false or can be ommited
    active: [Boolean, undefined],
    // strict value
    type: 'SME'
}

Examples

Validating an object

validateObject(validObject, {
    id: 10,
    name: 'John Wick',
    email: '[e-mail]'
})
 
// result: undefined
 
validateObject(validObject, {
    id: 10,
    name: null,
})
 
// result: [
//    'expected String at name',
//    'expected String at email'
// ]

Validating optional values

var validObject = {
    patient: {
        bloodType: ['A', 'B', 'AB', 'O']
    }
}
 
validateObject(validObject, {
    patient: {
        bloodType: 'A'
    }
})
 
// result: undefined
 
validateObject(validObject, {
    patient: {
        bloodType: 'Z'
    }
})
 
// result: [ 'expected any from [A, B, AB, O] at patient.bloodType' ]

Validating array contents

Provide an array with a single element in order to define an array validation object

var validObject = {
    characters: [{filmId: Number, name: String}]
}
 
validateObject(validObject, { characters: [
    {
        filmId: 10,
        name: 'John Wick'
    },
    {
        filmId: 10
    }
]})
 
// result: [ 'expected String at characters[1].name' ]

In order to validate array contents with optionals, provide an array within an array

var validObject = {
    characters: [[
        {filmId: Number, name: String},
        {deleted: true}
    ]]
}
 
validateObject(validObject, {
    characters: [
        {
            filmId: 10,
            name: 'John Wick'
        },
        {
            filmId: 10,
            deleted: true
        }
    ]
})
 
// result: undefined
 
validateObject(validObject, {
    characters: [
        {
            filmId: 10,
            name: 'John Wick'
        },
        {
            filmId: 10
        }
    ]
})
 
// result: [ 'expected any from [Object {filmId<Number>, name<String>}, Object {deleted: true}] at characters[1]' ]

Test

node test

Licence

MIT