DFS without helpers

app.js

traverseDFS(type) {
    //if there is no root, return false
    if (!this.root) {
      return false;
    }
    //make a variable for tree values
    const treeValues = [];
    //current values always starts at root
    let current = this.root;

    //helper methods go here
    
    //switch statment to select proper order and start recursive function calls
    switch (type) {
      case "pre":
        preOrderHelper(current);
        break;
      case "post":
        postOrderHelper(current);
        break;
      case "in":
        inOrderHelper(current);
        break;
    }
    //return array
    return treeValues;
 }