Morph

MorphJS transforms object literals into different structures using a simple schema such as formatting database results into a format suitable for an API output.

Install

npm i morphjs

Example

Original input:

const input = {
  _id: new objectID(),
  code: '123',
  items: [{
    cost: 45,
    name: 'An item'
  }, {
    cost: 10,
    name: 'Another item'
  }],
  recipient: {
    email: 'me@example.org',
    first: 'Sponge',
    last: 'Bob'
  }
}

Transformation schema:

const schema = {
  id: '@_id',
  company: 'My company',
  email: '@recipient.email',
  name: (doc) => {
    return doc.recipient.first + ' ' +  doc.recipient.last
  },
  items: '@items',
  count: '#items'
}

Apply:

const result = applyMask(input, schema)

Output:

const expected = {
  id: '507f191e810c19729de860ea',
  company: 'My company',
  email: 'me@example.org',
  name: 'Sponge Bob',
  items: [{
    cost: 45,
    name: 'An item'
  }, {
    cost: 10,
    name: 'Another item'
  }],
  count: 2
}    

Rules

Path reference

Values prefixed with @ are used to traverse the input object.

Ex:

name: @recipient.name.first

will look for the name field in:

{
    recipient: {
        name: {
            first: 'Sponge'
        }
    }
}

Strings

A quoted string will be used as is. Ex:

version: '1.0'

Counts

Array lengths count can be obtained by prefixing value with @.

Ex:

total: '@items'

Functions

If more functionality is necessary you can also use a function. This function is given the input document as a parameter.

Ex:

name: doc => doc.recipient.first + ' ' +  doc.recipient.last

Buffer, Dates and Mongo ObjectID

If a Buffer or Date instance or an Mongo ObjectID is provided it will be coerced into a string.

Ex:

// Input
_id: new objectID('28d64ae8122ab883bbc167ef'),

// Schema
id: _id

// Output
id: '28d64ae8122ab883bbc167ef'