Simulate the tournament

[klemonade]

Preface: I'm so new to this. Please be kind to me 🙏🏻

I am trying to simulate the tournament by using this function

const proceed = async () => {
		data = await manager.get.tournamentData(0);
		data.match.forEach(async (match) => {
			if (match.status === 0) {
				return;
			}
			if (match.round_id === round) {
                if (Math.random() > 0.5) {

                    await manager.update.match({
                        id: match.id,
                        opponent1: { score: 1, result: 'win' },
                        opponent2: { score: 0, result: 'loss' }
                    });
                    left.push(match.opponent1.id)
                } else {
                    await manager.update.match({
                        id: match.id,
                        opponent1: { score: 0, result: 'loss' },
                        opponent2: { score: 1, result: 'win' }
                    });
                    left.push(match.opponent2.id)
                }
			}
		});
    }

However, when I run this function, it does not proceed to the next round.

Do you have any suggestions on this? Thank you in advance.

Dependency

• node: 16.19.1
• brackets-manager: 1.5.5
• brackets-memory-db: 1.0.4
• bracket-viewer: latest from cdn

[Drarig29]

Hey! So you have 2 issues here.

First, be aware that functional array methods in JS — like map(), reduce(), forEach() — are not compatible with async. They won't await between each iteration as you might think.

So what you should do instead of using forEach() is to map() your array items to an array of promises, that can then be awaited with Promise.all():

await Promise.all(data.match.map(async (match) => {
  // ...
  await manager.update.match({ ... })
}))

And second, what you are doing here is running promises in concurrence (NB: Node.js doesn't do parallel).

But my storage implementations — brackets-json-db, brackets-memory-db... — do not support concurrent operations.
Since you are updating each round-2 match twice concurrently, only the last update remains.

So you should use a normal for ... of loop instead:

for (const match of data.match) {
    if (match.status === 0)
        continue;

    if (match.round_id === round) {
        if (Math.random() > 0.5) {
            await manager.update.match({
                id: match.id,
                opponent1: { score: 1, result: 'win' },
                opponent2: { score: 0, result: 'loss' },
            });
            left.push(match.opponent1.id);
        } else {
            await manager.update.match({
                id: match.id,
                opponent1: { score: 0, result: 'loss' },
                opponent2: { score: 1, result: 'win' },
            });
            left.push(match.opponent2.id);
        }
    }
}

[Drarig29]

With this code, I managed to have this result:

[klemonade]

It worked perfectly. Thank you.

The concept is somewhat confusing for me, but I'll try to understand. Thank you again.