renderConstructTree.ts

import { Construct } from 'constructs';

function renderConstructTree(scope: Construct, renderNode?: (construct: Construct) => string): string {
  let result = '';
  function renderBranch(tree: Construct, branch: string) {
    if (renderNode === undefined) {
      renderNode = (c: Construct) => `${c.constructor.name} [${c.node.id}]`;
    }
    const isGraphHead = branch.length === 0;
    if (!isGraphHead) {
      result += '\n';
    }
    result += branch;
    if (!isGraphHead) {
      if (!tree.node.children || tree.node.children.length === 0) {
        result += '─ ';
      } else {
        result += '┬ ';
      }
    }
    result += renderNode(tree);
    let baseBranch = branch;
    if (!isGraphHead) {
      const isChildOfLastBranch = branch.slice(-2) === '└─';
      baseBranch = branch.slice(0, -2) + (isChildOfLastBranch ? '  ' : '│ ');
    }
    const nextBranch = baseBranch + '├─';
    const lastBranch = baseBranch + '└─';

    tree.node.children.forEach((child, index) => {
      renderBranch(child, tree.node.children.length - 1 === index ? lastBranch : nextBranch);
    });
  }
  renderBranch(scope, '');
  return result;
}