About The Project

Objects by their nature are an unordered collection of properties. JS engines typically serialize objects in consistent ways. This is perfectly fine for system consumption. However; human readability can be greatly improved by forcing a particular order. The use case arose by the desire to save JSON to disk, review by humans and comparison tools.

Getting Started

Prerequisites

• Node.js with npm

Installation

Using npm:

npm install @RickZaki/json-stringify-sorted

Usage

CommonJS

const jsonStringifySorted = require('json-stringify-sorted');

ECMAScript Modules

import * as jsonStringifySorted from 'json-stringify-sorted';

examples

Simple example

cont sampleObject = {d:[8,6,7,5,3,0,9], a: 1, c:true, b:"b"};
const sortedObject = jsonStringifySorted(sampleObject);
console.log(sortedObject); // {"a":1,"b":"b","c":true,"d":[8,6,7,5,3,0,9]}

AS you can see arrays remain unaltered.

Nested example

cont sampleObject = {d:{h:"h", e:"e"}, a: 1, c:true, b:"b"};
const sortedObject = jsonStringifySorted(sampleObject);
console.log(sortedObject); // {"a":1,"b":"b","c":true,"d":{"e":"e","h":"h"}}

Nested objects are also sorted

Key Order

The second optional paramter is used to determine the sort order of the keys.

cont sampleObject = {d:{h:"h", e:"e"}, a: 1, c:true, b:"b"};
const sortedObject = jsonStringifySorted(sampleObject, ['a', 'e', 'd', 'c']);
console.log(sortedObject); // {"a":1,"d":{"e":"e"},"c":true}

a few ccaveats with this use case:

1. Keys not provided in the order array are omitted from the result
2. The order for root and nested object keys are intertwined. Should a nested object have the same keys, the order will be identical. You cann specify a before b on the ancestor, but b before a on descendant.

Custom sort function

As the utility uses Array.sort, you can supply a custom sort compare function. Here's one that forces some keys in order, and the remaining in alphabetical order.

const compareFn = (a, b) =>{
    const keyOrder = ['c', 'b'];
    const aIndex = keyOrder.indexOf(a);
    const bIndex = keyOrder.indexOf(b);
    if (aIndex > -1 || bIndex > -1) {
        if (aIndex == -1) {
            return 1;
            } else if (bIndex == -1) {
            return -1;
            } else if (aIndex < bIndex) {
            return -1;
            } else {
            return 1;
            }
    }
    if (a < b) {
        return -1;
    } else {
        return 1;
    }
};
cont sampleObject = {d:{h:"h", e:"e"}, a: 1, c:true, b:"b"};
const sortedObject = jsonStringifySorted(sampleObject, compareFn);
console.log(sortedObject); // {"c":true,"b":"b","a":1,"d":{"e":"e","h":"h"}}

Formatting

the third optional parameter is an number of spaces to include in the output. Just like JSON.strigify

cont sampleObject = { a: 1, c:true, b:"b"};
const sortedObject = jsonStringifySorted(sampleObject, null, 2);
console.log(sortedObject); /*
{
  "a": 1,
  "b": "b",
  "c": true
}
*/

Contributing

Contributions are what make the open source community such an amazing place to learn, inspire, and create. Any contributions you make are greatly appreciated.

If you have a suggestion that would make this better, please fork the repo and create a pull request. You can also simply open an issue with the tag "enhancement". Don't forget to give the project a star! Thanks again!

License

Distributed under the MIT License. See LICENSE for more information.

Contact

Rick Zaki - GitHub-at-RickZaki.com

Project Link: https://github.com/RickZaki/json-stringify-sorted