topo

Adding Nodes

This feature allows you to add nodes to the topo instance. Each node can be assigned to a group and can specify dependencies using the 'after' and 'before' options.

const Topo = require('topo');
const topo = new Topo();
topo.add('a', { group: 'group1' });
topo.add('b', { group: 'group2', after: ['group1'] });
console.log(topo.nodes);

Sorting Nodes

This feature sorts the nodes based on their dependencies. The 'sort' method returns an array of nodes in the correct order, ensuring that each node appears after its dependencies.

const Topo = require('topo');
const topo = new Topo();
topo.add('a', { group: 'group1' });
topo.add('b', { group: 'group2', after: ['group1'] });
topo.add('c', { group: 'group3', before: ['group2'] });
const sorted = topo.sort();
console.log(sorted);

Handling Cyclic Dependencies

This feature demonstrates how the topo package handles cyclic dependencies. If a cyclic dependency is detected, an error is thrown, preventing the sort operation from completing.

const Topo = require('topo');
const topo = new Topo();
topo.add('a', { group: 'group1' });
topo.add('b', { group: 'group2', after: ['group1'] });
topo.add('c', { group: 'group3', after: ['group2', 'group1'] });
topo.add('d', { group: 'group4', after: ['group3', 'group1'] });
try {
  topo.add('e', { group: 'group5', after: ['group4', 'group1', 'group3'] });
  topo.add('f', { group: 'group6', after: ['group5', 'group2'] });
  const sorted = topo.sort();
  console.log(sorted);
} catch (err) {
  console.error('Cyclic dependency detected:', err.message);
}