World.terminate() never resolves

[calebj0seph]

Consider the following:

import { System, World } from '@lastolivegames/becsy';

class SystemA extends System {}

class SystemB extends System {
  constructor() {
    super();
    this.schedule((s) => s.after(SystemA));
  }
}

class SystemC extends System {
  constructor() {
    super();
    this.schedule((s) => s.after(SystemA));
  }
}

const startAndTerminate = async () => {
  console.log('Starting world');

  const world = await World.create({
    defs: [SystemA, SystemB, SystemC],
  });

  await world.terminate();

  console.log('Terminated!');
};

startAndTerminate();

The line console.log('Terminated!') will never execute as world.terminate() never resolves.

This is currently breaking our application as we need to wait for the world to terminate before creating a new world when another page is loaded.

Seems like the bug is in SimplePlan.finalize() on line 82 and 90: https://github.com/LastOliveGames/becsy/blob/d97a10632dcd7df75cf5142da0c4e89d6161fdd6/src/planner.ts#L82;L90

this.graph.traverse() can return an empty array, meaning the line if (!systems) return resolve() never gets executed causing the promise to never resolve. Checking if (!systems?.length) return resolve() instead seems like it would fix the issue.

[pkaminski]

Thanks, reproduced. The problem is actually with aliasing of the traversal array in an attempt to minimize GC -- I'll come up with a fix tonight.

[pkaminski]

Fixed in 0.12.3.

[calebj0seph]

Thanks for fixing this so quickly! Really appreciated 😃