add generic stateful input streaming

packages/shared/test/flux.test.mjs

@@ -22,12 +22,16 @@ test("Flux Relay is a complete game defined through the public authoring API", (
 
   const server = fluxGame.createServer();
   server.addPlayer(1);
-  assert.deepEqual(server.submitInput(1, createThrustPacket(1, 1)), {
+  const thrustPacket = createThrustPacket(1, 1);
+  assert.deepEqual(server.submitInput(1, thrustPacket), {
     accepted: true,
   });
 
   const events = [];
   for (let tick = 0; tick < 180; tick += 1) {
+    if (tick > 0 && tick % 6 === 0) {
+      assert.deepEqual(server.submitInput(1, thrustPacket), { accepted: true });
+    }
     events.push(...server.step().events);
   }