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Hello World

Game Logic​

Game logic lives in portable, headless TypeScript files with no dependencies on the browser or renderer.

game.ts

import { Bloop } from "@bloopjs/bloop";

export const game = Bloop.create({
  // bag is a singleton object for global game state - useful for prototyping
  bag: {
    clicks: 0,
  }
})

// game systems run in the order you define them
game.system('input', {
  // systems update state in response to events:
  // * input events like keydown, mousemove
  // * frame lifecycle events like update
  // * network events like peer join
  mousedown({event, bag}) {
    bag.clicks++;
    console.log(`Clicked ${bag.clicks} times!`)
  },
})

Run on the Web​

To run on the web, use the @bloopjs/web package.

main.ts

import { start } from "@bloopjs/web";
import { game } from "./game";

// start the game and hook into requestAnimationFrame for stepping
const app = await start(game)

// wire up hot module reloading for changing game code without losing state
import.meta.hot?.accept("./game", async (newModule) => {
  await app.acceptHmr(newModule?.game);
});

Run in Tests​

All game code is unit testable.

test/game.test.ts

import { expect, it } from "bun:test";
import { mount } from "@bloopjs/bloop"
import { game } from "../game"

it('registers clicks', async () => {
  const {sim} = await mount(game);

  sim.step();
  expect(game.bag.clicks).toEqual(0);

  sim.emit.mousedown('left');
  sim.step();
  expect(game.bag.clicks).toEqual(1);
})

Run in Godot​

Working on this for Q1 2026. Follow along in the Discord.