Get Dependencies Recursive

deps-promise.js

const fetch = require('node-fetch');

function getDependencies(packageName) {
    const url = `https://registry.npmjs.org/${packageName}/latest`;
    return fetch(url).then((response) => {
        return response.json();
    }).catch(() => {
        return [];
    }).then((body) => {
        return Array.from(Object.keys(body.dependencies));
    }).catch(() => {
        return [];
    });
}

function getAllDependencies(packageName) {
    return getDependencies(packageName).then(deps => {
        return Promise.all(deps.map(dep => {
            return getAllDependencies(dep).then(subDepValues => {
                return [...subDepValues, ...deps];
            });
        })).then(values => {
            return [...new Set([].concat(...values))];
        });
    });
}

getAllDependencies('forever').then(values => {
    console.log(values);
});