fix: ensure useplayers not nil (#472)

.changeset/userplayers-nil.md

@@ -0,0 +1,5 @@
+---
+"@empirica/core": patch
+---
+
+Ensure `usePlayers` never returns undefined (expect in unmanaged games).

lib/@empirica/core/src/admin/runloop.ts

@@ -228,6 +228,15 @@ export class Runloop<
     const res = await Promise.allSettled(promises);
     for (const r of res) {
       if (r.status === "rejected") {
+        // We can ignore invalid transition errors, as they are likely due to
+        // the same transition triggered concurrently from multiple places.
+        if (
+          r.reason instanceof String &&
+          r.reason.includes("invalid transition")
+        ) {
+          continue;
+        }
+
         warn(`failed load: ${r.reason}`);
       }
     }

lib/@empirica/core/src/player/classic/react/EmpiricaContext.tsx

@@ -13,7 +13,7 @@ import {
 } from "../../react/hooks";
 import { Lobby as DefaultLobby } from "./Lobby";
 import { Steps, StepsFunc } from "./Steps";
-import { useGame, usePlayer, useRound, useStage } from "./hooks";
+import { useGame, usePlayer, usePlayers, useRound, useStage } from "./hooks";
 
 export interface EmpiricaContextProps {
   children: React.ReactNode;
@@ -168,6 +168,7 @@ function EmpiricaInnerContext({
   unmanagedGame = false,
 }: EmpiricaInnerContextProps) {
   const player = usePlayer();
+  const players = usePlayers();
   const game = useGame();
   const stage = useStage();
   const round = useRound();
@@ -192,7 +193,7 @@ function EmpiricaInnerContext({
     return <Exit exitSteps={exitSteps} finished={finished} />;
   }
 
-  if (!unmanagedGame && (!stage || !round)) {
+  if (!unmanagedGame && (!stage || !round || !players)) {
     return <LoadingComp />;
   }
 

tests/stress/tests/attributes.spec.js

@@ -12,9 +12,7 @@ import { sleep } from "./utils";
 // test.
 test.describe.configure({ mode: "serial" });
 
-test.only("attribute as object, correct equality check", async ({
-  browser,
-}) => {
+test("attribute as object, correct equality check", async ({ browser }) => {
   const ctx = new Context(browser);
 
   const playerCount = 2;

tests/stress/tests/main.spec.js

@@ -33,12 +33,12 @@ test("1 x 10 player", async ({ browser }) => {
   await ctx.close();
 });
 
-test("10 full games, 2 players", async ({ browser }) => {
+test("2-round 5-stage-each game, 2 players", async ({ browser }) => {
   const ctx = new Context(browser);
 
   const playerCount = 2;
-  const roundCount = 1;
-  const stageCount = 10;
+  const roundCount = 2;
+  const stageCount = 5;
   const totalStages = roundCount * stageCount;
 
   await ctx.start();