merge package.json helper

merge-package-json.js

const fs = require("fs");

var a = JSON.parse(fs.readFileSync('p1.json', "utf8"));
var b = JSON.parse(fs.readFileSync('p2.json', "utf8"));

var dst = {};

function merge(destination, source, key) {
    if (key === undefined) {
        Object.keys(source).forEach(k => merge(destination, source, k));
    }
    else if (source[key] instanceof Object) {
        if (destination[key] === undefined) {
            destination[key] = {}
        }
        Object.keys(source[key]).forEach(k => merge(destination[key], source[key], k));
    }
    else {
        if (destination[key] === undefined) {
            destination[key] = [source[key]]
        }
        else if (!destination[key].includes(source[key])) {
            destination[key].push(source[key])
        }
    }
}
merge(dst, a)
merge(dst, b)

console.log(dst)

var result = {};
function simplify(target, source) {
    Object.keys(source).forEach(k => {
        if (!(source[k] instanceof Array)) {
            target[k] = {}
            simplify(target[k], source[k])
        }
        else {
            if (source[k].length === 1) {
                target[k] = source[k][0]
            }
            else {
                target[k] = source[k]
            }
        }
    })
}

simplify(result, dst)

console.log(result)

p1.json

{
    "name": "my-package",
    "dependencies": {
        "babel": "^5.4.1",
        "eslint": "^0.22.1"
    }
}

p2.json

{
    "name": "my-package",
    "dependencies": {
        "babel": "^5.2.2",
        "lodash": "^3.2.5"
    }
}