silphius/app/engine.test.js

import {expect, test} from 'vitest';

import {RESOLUTION} from '@/constants.js'
import Server from '@/net/server/server.js';

import Engine from './engine.js';

class TestServer extends Server {
  constructor() {
    super();
    this.data = {};
  }
  async readData(path) {
    if (path in this.data) {
      return this.data[path];
    }
    const error = new Error();
    error.code = 'ENOENT';
    throw error;
  }
  async writeData(path, view) {
    this.data[path] = view;
  }
}

test('visibility-based updates', async () => {
  const engine = new Engine(TestServer);
  // Connect an entity.
  await engine.connectPlayer(0, 0);
  const ecs = engine.ecses['homesteads/0'];
  // Create an entity.
  const entity = ecs.get(ecs.create({
    Momentum: {x: 1, y: 0},
    Position: {x: (RESOLUTION.x * 1.5) + 32 - 3, y: 20},
    VisibleAabb: {},
  }));
  // Tick and get update. Should be a full update.
  engine.tick(1);
  expect(engine.updateFor(0))
    .to.deep.include({2: {MainEntity: {}, ...ecs.get(2).toJSON()}, 3: ecs.get(3).toJSON()});
  // Tick and get update. Should be a partial update.
  engine.tick(1);
  expect(engine.updateFor(0))
    .to.deep.include({
      3: {
        Position: {x: (RESOLUTION.x * 1.5) + 32 - 1},
        VisibleAabb: {
          x0: 1199,
          x1: 1263,
        },
      },
    });
  // Tick and get update. Should remove the entity.
  engine.tick(1);
  expect(engine.updateFor(0))
    .to.deep.include({3: false});
  // Aim back toward visible area and tick. Should be a full update for that entity.
  entity.Momentum.x = -1;
  engine.tick(1);
  expect(engine.updateFor(0))
    .to.deep.include({3: ecs.get(3).toJSON()});
});