[core] Slow execution at SynthUtils.toCloudFormation on v1.57.0

[idm-ryou]

Our unit test execution takes considerably long time, when we upgrade CDK from v1.56.0 to v1.57.0.

• v1.56.0: $ jest took 59 seconds
• v1.57.0: $ jest took 673 seconds

I suspect that changes from #9342 affected our codes.
Is there any workaround to make it faster like previous version?

Reproduction Steps

Our test code something looks like followings:

import * as cdk from "@aws-cdk/core";
import "@aws-cdk/assert/jest";
import { SynthUtils } from "@aws-cdk/assert";
import { app } from "./app";

describe("app", () => {
  const stacks = app.node.children
    .filter(cdk.Stack.isStack);

  test("stack templates match snapshots", () => {
    stacks.forEach((stack) => {
      expect(SynthUtils.toCloudFormation(stack)).toMatchSnapshot(
        stack.stackName
      );
    });
  });
});

The app is pretty large and it has 55 stacks and the snapshot file has about 23,000 lines.

Environment

• CLI Version :1.57.0
• Framework Version:1.57.0
• Node.js Version:v12.18.3
• OS :Linux(Docker)
• Language (Version):TypeScript (3.8.3)

Other

---

This is 🐛 Bug Report

[rix0rrr]

Investigating:

• A lot of time is spent in collectRuntimeInformation (specifically: findNpmPackage).
• Besides that, captureStackTrace in PostResolveToken is quite expensive (and we create A LOT of those).

The first finding will be addressed in #10306.

The second one is probably an easy enough fix. I thought we had disabled stack trace collection for tests using an environment variable. Maybe that change got reverted by accident?

[github-actions]

⚠️COMMENT VISIBILITY WARNING⚠️

Comments on closed issues are hard for our team to see.
If you need more assistance, please either tag a team member or open a new issue that references this one.
If you wish to keep having a conversation with other community members under this issue feel free to do so.