Rapier 2D (@dimforge/rapier2d-compat 0.20) comes in as the physics engine: the editor loads it once in the background right after opening a project from its own chunk, so the main bundle grows by 0.19 KB gzip and the first frame does not wait; loadPhysics, physicsStatus and the 100 px = 1 m conversion live in src/runtime/physics/engine.ts, __gm.physics() reports the state, unit tests pin free fall and a box resting on a box, and e2e module 41 pins that Rapier is ready from its own chunk without console noise (#145)

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

tools/e2e/41-physics.mjs

@@ -0,0 +1,28 @@
+/**
+ * The physics engine (Rapier) loads in the editor, in the background after the first project is
+ * open, from a chunk of its own – the editor bundle does not carry it.
+ */
+export async function physics(t) {
+  const { check, json, waitUntil, consoleLog } = t;
+
+  await waitUntil(`['ready', 'failed'].includes(__gm.physics().state)`, { timeout: 15000 });
+  const status = await json('__gm.physics()');
+  check(
+    'Rapier loads in the editor without Play',
+    status.state === 'ready' && status.version === '0.20.0',
+    JSON.stringify(status),
+  );
+  const scripts = await json(
+    `performance.getEntriesByType('resource').map((e) => e.name).filter((n) => n.endsWith('.js')).map((n) => n.split('/').pop())`,
+  );
+  check(
+    'it comes from a chunk of its own',
+    scripts.some((name) => /^rapier-.+\.js$/.test(name)),
+    JSON.stringify(scripts),
+  );
+  check(
+    'loading it writes nothing to the console',
+    !consoleLog.some((line) => /\[physics\]|rapier/i.test(line)),
+    consoleLog.filter((line) => /\[physics\]|rapier/i.test(line)).join(' | '),
+  );
+}

tools/e2e/index.mjs

@@ -43,6 +43,7 @@ import { nineSlice } from './37-nine-slice.mjs';
 import { plugins } from './38-plugins.mjs';
 import { tile } from './39-tile.mjs';
 import { tilemap } from './40-tilemap.mjs';
+import { physics } from './41-physics.mjs';
 
 export const STEPS = [
   hierarchy,
@@ -85,4 +86,5 @@ export const STEPS = [
   plugins,
   tile,
   tilemap,
+  physics,
 ];