Walk through dependency tree of installed packages via `npm ls`

deptree-json-sync.js

const spawn = require('cross-spawn');
const path = require('path')

const ls = spawn.sync('npm', ['ls','--json']);

const tree = JSON.parse(ls.stdout)

const walkDepTree = (tree,cb) => {
    const deps = tree.dependencies
    if(deps) {
        Object.keys(deps).forEach(name => {
            const dep = deps[name];
            cb(name,dep)
            walkDepTree(dep,cb);
        })
    }
}

walkDepTree(
    tree,
    (name,data)=> {
        if(data.resolved.startsWith('https://registry.npmjs.org/'))
            console.log(`${name} @ ${data.resolved}`)
    }
)