@rafa93br/toposort/index.js

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
var hasIncomingEdges = function hasIncomingEdges(node) {
  return node.edges.length;
};
var noIncomingEdges = function noIncomingEdges(node) {
  return !node.edges.length;
};

var removeEdge = function removeEdge(adjacentVertex, node) {
  node.edges = node.edges.filter(function (vertex) {
    return vertex !== adjacentVertex;
  });
  return node;
};

exports.default = function () {
  var nodes = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : [];

  var noEdges = nodes.filter(noIncomingEdges);
  var withEdges = nodes.filter(hasIncomingEdges);
  var sorted = [];

  while (noEdges.length) {
    var node = noEdges.pop();
    sorted.push(node);

    withEdges = withEdges.map(removeEdge.bind(null, node.name));
    var newNoEdges = withEdges.filter(noIncomingEdges);
    noEdges = noEdges.concat(newNoEdges);

    withEdges = withEdges.filter(hasIncomingEdges);
  }
  return sorted.map(function (node) {
    return node.name;
  });
};