From 5c8d5a63d8589c5795dc1247e86601ac90cef043 Mon Sep 17 00:00:00 2001
From: Guangcong Luo <guangcongluo@gmail.com>
Date: Fri, 1 Sep 2017 06:45:13 -0400
Subject: [PATCH] Refactor some ladder functions to async/await

---
 ladders-matchmaker.js | 27 ++++++++++++---------------
 ladders.js            | 42 ++++++++++++++++++++----------------------
 2 files changed, 32 insertions(+), 37 deletions(-)

diff --git a/ladders-matchmaker.js b/ladders-matchmaker.js
index 28b063c1c3..ac1341c4d1 100644
--- a/ladders-matchmaker.js
+++ b/ladders-matchmaker.js
@@ -58,27 +58,24 @@ class Matchmaker {
 		return true;
 	}
 
-	searchBattle(user, formatid) {
+	async searchBattle(user, formatid) {
 		if (!user.connected) return;
 		formatid = Dex.getFormat(formatid).id;
-
-		return Promise.all([
-			Promise.resolve(user.userid),
-			user.prepBattle(formatid, 'search', null),
-			Ladders(formatid).getRating(user.userid),
-		]).then(([userId, validTeam, rating]) => {
-			if (userId !== user.userid) return;
-			return this.finishSearchBattle(user, formatid, validTeam, rating);
-		}, err => {
+		let oldUserid = user.userid;
+		let validTeam, rating;
+		try {
+			[validTeam, rating] = await Promise.all([
+				user.prepBattle(formatid, 'search', null),
+				Ladders(formatid).getRating(user.userid),
+			]);
+		} catch (e) {
 			// Rejects iff ladders are disabled, or if we
 			// retrieved the rating but the user had changed their name.
-
 			if (Ladders.disabled) return user.popup(`The ladder is currently disabled due to high server load.`);
 			// User feedback for renames handled elsewhere.
-		});
-	}
-
-	finishSearchBattle(user, formatid, validTeam, rating) {
+			return;
+		}
+		if (oldUserid !== user.userid) return;
 		if (validTeam === false) return;
 
 		const search = new Search(user.userid, validTeam, rating);
diff --git a/ladders.js b/ladders.js
index be77558f75..7b1c1aa387 100644
--- a/ladders.js
+++ b/ladders.js
@@ -128,41 +128,39 @@ class Ladder {
 	 * ladder toplist, to be displayed directly in the ladder tab of the
 	 * client.
 	 */
-	getTop() {
+	async getTop() {
 		let formatid = this.formatid;
 		let name = Dex.getFormat(formatid).name;
-		return this.ladder.then(ladder => {
-			let buf = `<h3>${name} Top 100</h3>`;
-			buf += `<table>`;
-			buf += `<tr><th>` + ['', 'Username', '<abbr title="Elo rating">Elo</abbr>', 'W', 'L', 'T'].join(`</th><th>`) + `</th></tr>`;
-			for (let i = 0; i < ladder.length; i++) {
-				let row = ladder[i];
-				buf += `<tr><td>` + [
-					i + 1, row[2], `<strong>${Math.round(row[1])}</strong>`, row[3], row[4], row[5],
-				].join(`</td><td>`) + `</td></tr>`;
-			}
-			return [formatid, buf];
-		});
+		const ladder = await this.ladder;
+		let buf = `<h3>${name} Top 100</h3>`;
+		buf += `<table>`;
+		buf += `<tr><th>` + ['', 'Username', '<abbr title="Elo rating">Elo</abbr>', 'W', 'L', 'T'].join(`</th><th>`) + `</th></tr>`;
+		for (let i = 0; i < ladder.length; i++) {
+			let row = ladder[i];
+			buf += `<tr><td>` + [
+				i + 1, row[2], `<strong>${Math.round(row[1])}</strong>`, row[3], row[4], row[5],
+			].join(`</td><td>`) + `</td></tr>`;
+		}
+		return [formatid, buf];
 	}
 
 	/**
 	 * Returns a Promise for the Elo rating of a user
 	 */
-	getRating(userid) {
+	async getRating(userid) {
 		let formatid = this.formatid;
 		let user = Users.getExact(userid);
 		if (Ladders.disabled === true || Ladders.disabled === 'db' && (!user || !user.mmrCache[formatid])) {
-			return Promise.reject(new Error(`Ladders are disabled.`));
+			throw new Error(`Ladders are disabled.`);
 		}
 		if (user && user.mmrCache[formatid]) {
-			return Promise.resolve(user.mmrCache[formatid]);
+			return user.mmrCache[formatid];
 		}
-		return this.ladder.then(() => {
-			if (user.userid !== userid) return Promise.reject(`Expired rating for ${userid}`);
-			let index = this.indexOfUser(userid);
-			if (index < 0) return (user.mmrCache[formatid] = 1000);
-			return (user.mmrCache[formatid] = this.loadedLadder[index][1]);
-		});
+		await this.ladder;
+		if (user.userid !== userid) throw new Error(`Expired rating for ${userid}`);
+		let index = this.indexOfUser(userid);
+		if (index < 0) return (user.mmrCache[formatid] = 1000);
+		return (user.mmrCache[formatid] = this.loadedLadder[index][1]);
 	}
 
 	/**