Breadth-first Graph Traversal in ES6

graph-es6.js

"use strict";
const G = {
    vertices: [{
        edges: [1, 4]
    }, {
        edges: [0, 2, 3, 4]
    }, {
        edges: [1, 3]
    }, {
        edges: [1, 2, 4]
    }, {
        edges: [0, 1, 3]
    }]
};

let bfs = (vertices, s) => {
    let vs = vertices.map((v, i) => {
    	return Object.assign( {}, v, {color: 'white', distance: Infinity, parent: null, id: `edge ${i}`});
    });
    Object.assign(vs[s], {color: 'grey', distance: 0});

    let Q = [s];
    while (Q.length) {
	let v = vs[Q.shift()];
	const d = v.distance+1;
	v.edges.filter(e => vs[e].color === 'white').forEach(e => {
	    Object.assign(vs[e], { color: 'grey', distance: d, parent: v.id});
	    Q.push(e);
        });
        v.color = 'black';
    }
    return vs;
};

console.log( JSON.stringify( bfs(G.vertices, 0), null, 2) );