typed-openapi/src/topological-sort.ts

/** @see https://gist.github.com/RubyTuesdayDONO/5006455 */
export function topologicalSort(graph: Map<string, Set<string>>) {
  const sorted: string[] = [], // sorted list of IDs ( returned value )
    visited: Record<string, boolean> = {}; // hash: id of already visited node => true

  function visit(name: string, ancestors: string[]) {
    if (!Array.isArray(ancestors)) ancestors = [];
    ancestors.push(name);
    visited[name] = true;

    const deps = graph.get(name);
    if (deps) {
      deps.forEach((dep) => {
        if (ancestors.includes(dep)) {
          // if already in ancestors, a closed chain (recursive relation) exists
          return;
          // throw new Error(
          //     'Circular dependency "' + dep + '" is required by "' + name + '": ' + ancestors.join(" -> ")
          // );
        }

        // if already exists, do nothing
        if (visited[dep]) return;
        visit(dep, ancestors.slice(0)); // recursive call
      });
    }

    if (!sorted.includes(name)) sorted.push(name);
  }

  // 2. topological sort
  graph.forEach((_, name) => visit(name, []));

  return sorted;
}