From 891b046a6af7fbae3a22269ee6fcc2a46eaaa98e Mon Sep 17 00:00:00 2001
From: Guangcong Luo <guangcongluo@gmail.com>
Date: Tue, 13 May 2025 11:27:29 -0700
Subject: [PATCH] Sim: Emit requests after updates

Fixes #8546
---
 sim/battle.ts              | 8 +++++++-
 sim/side.ts                | 4 ++--
 test/server/room-battle.js | 4 ++--
 3 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/sim/battle.ts b/sim/battle.ts
index fcb272dab8..6842b42a90 100644
--- a/sim/battle.ts
+++ b/sim/battle.ts
@@ -145,6 +145,7 @@ export class Battle {
 	readonly messageLog: string[];
 	sentLogPos: number;
 	sentEnd: boolean;
+	sentRequests = true;
 
 	requestState: RequestState;
 	turn: number;
@@ -1329,8 +1330,9 @@ export class Battle {
 
 		const requests = this.getRequests(type);
 		for (let i = 0; i < this.sides.length; i++) {
-			this.sides[i].emitRequest(requests[i]);
+			this.sides[i].activeRequest = requests[i];
 		}
+		this.sentRequests = false;
 
 		if (this.sides.every(side => side.isChoiceDone())) {
 			throw new Error(`Choices are done immediately after a request`);
@@ -3211,6 +3213,10 @@ export class Battle {
 	sendUpdates() {
 		if (this.sentLogPos >= this.log.length) return;
 		this.send('update', this.log.slice(this.sentLogPos));
+		if (!this.sentRequests) {
+			for (const side of this.sides) side.emitRequest();
+			this.sentRequests = true;
+		}
 		this.sentLogPos = this.log.length;
 
 		if (!this.sentEnd && this.ended) {
diff --git a/sim/side.ts b/sim/side.ts
index 59b4df7940..d2bd2636e8 100644
--- a/sim/side.ts
+++ b/sim/side.ts
@@ -483,7 +483,7 @@ export class Side {
 		this.battle.send('sideupdate', `${this.id}\n${sideUpdate}`);
 	}
 
-	emitRequest(update: ChoiceRequest) {
+	emitRequest(update: ChoiceRequest = this.activeRequest!) {
 		this.battle.send('sideupdate', `${this.id}\n|request|${JSON.stringify(update)}`);
 		this.activeRequest = update;
 	}
@@ -495,7 +495,7 @@ export class Side {
 		const updated = update ? this.updateRequestForPokemon(update.pokemon, update.update) : null;
 		const type = `[${updated ? 'Unavailable' : 'Invalid'} choice]`;
 		this.battle.send('sideupdate', `${this.id}\n|error|${type} ${message}`);
-		if (updated) this.emitRequest(this.activeRequest!);
+		if (updated) this.emitRequest();
 		if (this.battle.strictChoices) throw new Error(`${type} ${message}`);
 		return false;
 	}
diff --git a/test/server/room-battle.js b/test/server/room-battle.js
index 773c2dd7e3..f8b51ace04 100644
--- a/test/server/room-battle.js
+++ b/test/server/room-battle.js
@@ -53,16 +53,16 @@ describe('Simulator abstraction layer features', () => {
 				'>player p1 {"name":"p1","avatar":"ethan","team":"","rating":1507,"seed":[59512,58581,51338,7861]}\n' +
 				'>player p2 {"name":"p2","avatar":"dawn","team":"","rating":1447,"seed":[33758,53485,62378,29757]}\n'
 			);
+			assert((await stream.read()).includes('|switch|'));
 			assert((await stream.read()).startsWith('sideupdate\np1\n|request|'));
 			assert((await stream.read()).startsWith('sideupdate\np2\n|request|'));
-			assert((await stream.read()).includes('|switch|'));
 			stream.write(
 				'>p1 move 1\n' +
 				'>p2 move 1\n'
 			);
+			assert((await stream.read()).includes('|move|'));
 			assert((await stream.read()).startsWith('sideupdate\np1\n|request|'));
 			assert((await stream.read()).startsWith('sideupdate\np2\n|request|'));
-			assert((await stream.read()).includes('|move|'));
 			stream.destroy();
 			assert.equal(PM.processes[0].getLoad(), 0);