json2kv

Dependencyless JS library that converts a generic JSON-like object to a map-like, key-value object.

• Overview
• Installation
• Motivation
• Usage
• Contributing
  • Development Scripts
  • Build Note
• Credits
• License

Overview

json2kv is a library that converts a generic JSON to a map-like, key-value object. All it needs is a JSON-ish datum (that is, either a real JSON file or a JS serializable Object), and a property name. User defined exceptions are supported too. At the moment, only a property from the immediate children is supported.

It is fully tested, with 100% coverage.

Installation

With yarn:

• yarn add json2kv

Or, with npm:

• npm i -S json2kv

Motivation

The foundations of this library have been laid on StackOverflow, after I've managed to provide [a meaningful answer](map given the 'value' property of all the nested objects) to this problem: create a key-value object given a JSON and a certain property, which is common among some of the nested objects. In other words, the problem this package solves is converting a JSON to a map structure (key-value object), filtering out the unnecessary props. Hence the name json2kv.

Usage

// import the library
import json2kv from 'json2kv';

// define the JSON-like data
const data = {
  some: 'string',
  someObjWithoutValueProp: {
    yep: 'nope'
  },
  battery: {
    value: 4.08,
    metadata: {
      // ...
    }
  },
  location: {
    value: {
      coordinates: 'Some location value'
    }
  },
  temperature: {
    value: 32.5,
    metadata: {
      // ...
    }
  }
};

const prop = 'value';
const result = json2kv(data, prop);

console.log(result);
/*
  {
    battery: 4.08,                         // value of data.battery.value 
    location: {                            // value of data.location.value
      coordinates: 'Some location value',
    },
    temperature: 32.5,                     // value of data.temperature.value
  }
*/

You can also define custom exceptions to override the behaviour for specific properties. To do you you need to define a Map<string, string>, having a child property of data as key (in this case, location, as in data.location), and the object path of the desired mapping as value (in this case, value.coordinates, as in data.location.value.coordinates).

const exceptions = new Map(); // Map<string, string>
exceptions.set('location', 'value.coordinates');
const resultWithExceptions = json2kv(data, prop, exceptions);

console.log(resultWithExceptions);
/*
  {
    battery: 4.08,                    // value of data.battery.value 
    location: 'Some location value',  // value of data.location.value.coordinates
    temperature: 32.5                 // value of data.temperature.value
  }
*/

Contributing

As always, contributions are always welcome, and remember:

• ⇄ Pull requests and ★ Stars are really welcome too.
• Just check out the dev scripts right below to get started.

Development scripts

flow

checks if Flow definitions are written properly

lint

checks if code conforms to linting rules (eslint)

• lint - will check js

• lint --fix - will automatically fix js

publish

Runs all the linting/test suites Creates a brand new build Pushes a release to npm

test

checks if all unit tests pass (jest)

• test:watch - run tests in watch-mode
• test:cov - run tests and displays coverage (which should't get below 100%!)
• test:ci - run global tests and checks, including linting and flow errors

Build note

You can build your own light version of setting the env.targets property in .babelrc to "node": "current". The version deployed to npm requires at least NodeJS 6.0.0.

Credits

This library is a fork of another project of mine, node-lib-boilerplate.

License

This project is MIT licensed.