An extension of topological sort to include checking for cycles in a graph

graphCycleDetection.js

// ... topological sort content
hasCycle() {
    inRecursionStack = [];
    marked = [];
    for (int i = 0; i < vertices; i++) {
      if (cycleDFS(i, inRecursionStack)) return true;
    }
    return false;
  }

  // keep track of items in the recursive tree, if any is found, return true;
  cycleDFS(int v, inRecursionStack) {
    if (marked[v]) return false;
    inRecursionStack[v] = true; // mark that its in recursion stack
    marked[v] = true;
    for (let edge of g.adj(v)) {
      if (inRecursionStack[edge]) return true;
      cycleDFS(edge, recStack);
    }
    recStack[v] = false; // removed from recursion stack
    return false;
  }

  run() {
  // ...
  console.log(test.hasCycle()) // false
}