@paulsmith/jsonconverter NPM

JSON Converter

This is yet another tool for converting JSON data composed in one format into JSON with some other schema. It supports:

Querying the source document with JMESPath expressions
JSON-serializable templates
Custom transformation logic (processors)
Chaining processors
Async processors
References

Getting Started

$ npm install @paulsmith/jsonconverter

Usage

Basic Usage

import { Converter } from '@paulsmith/jsonconverter'

const myTemplate = {
  mappings: [
    {
      path: 'milleniumFalcon.pilot', // Where the data will go in the target
      query: 'pilot', // Where to find the data in the source
      processors: ['trim', 'upper'] // Apply transformations
    }
  ]
}
const sourceData = { pilot: ' Han Solo  ' }
const converter = new Converter(myTemplate)

converter.render(sourceData).then(converted => console.log(converted.result))
// { milleniumFalcon: { pilot: 'HAN SOLO' } }

Add an arbitrary value to target JSON

const myTemplate = {
  mappings: [
    { path: 'isScoundrel', value: true },
    { path: 'pal', value: 'Lando' },
    { path: 'bestPal', value: 'Chewie' }
  ]
}
const sourceData = { name: 'Han Solo' }
const converter = new Converter(myTemplate)

converter.render(sourceData).then(converted => console.log({ ...sourceData, ...converted.result }))
// {
//  name: 'Han Solo',
//  isScoundrel: true,
//  pal: 'Lando',
//  bestPal: 'Chewie'
// }

Apply a custom function as a processor

const myTemplate = {
  mappings: [
    {
      path: 'hanSolo.kesselRun.parsecs',
      query: 'kesselRunParsecs',
      processors: [p => --p]
    }
  ]
}
const sourceData = { kesselRunParsecs: 13 }
const converter = new Converter(myTemplate)

converter.render(sourceData).then(converted => console.log(converted.result))
// { hanSolo: { kesselRun: { parsecs: 12 } } }

Compose processors by chaining them together

// Compose outcomes by chaining processors
const myTemplate = {
  mappings: [
    { path: 'name', query: 'name', processors: ['trim', 'upper'] },
    {
      path: 'bestPal',
      processors: [() => 'Chewie', 'upper']
    }
  ]
}
const sourceData = { name: '     Han Solo   ' }
const converter = new Converter(myTemplate)

converter.render(sourceData).then(converted => console.log({ ...sourceData, ...converted.result }))
// { name: 'HAN SOLO', bestPal: 'CHEWIE' }

Built-in Processors

Processor	Input	Produces	Arguments	Description
upper	String	String		Changes the input to all uppercase
lower	String	String		Changes the input to all lowercase
trim	String	String		Removes leading and trailing spaces
join	Array	String	`joiner` (default ', ')	Joins the Array elements into a single string, joined by the `joiner`
map	Array	Array	mapping function	Applies a mapping function to the array desc
query	Any	Any	A JMESPath query	Applies the JMESPath query to the provided value
slugify	String	String		Slugifies the string
titleCase	String	String		Returns the provide string In Title Case
toJson	Any	String		Applies JSON.stringify
sort	Array	Array	Sorting function	Sorts the provided array
slice	String	String	`start`, `end`	Returns part of a string
dateFormat	String	String		Applies `toISOString` to a date string
fetch	String (a URL)	Any	params object which will be passed to axios	Takes in a URL from the source, makes a request to the URL, and puts the response body into the target JSON

Acknowledgements

This library would have been less fun to write, and significantly less fun to test without the Paul Hallett's awesome SWAPI Star Wars API. May The Force be with you.