From fc8aa307562e805c2284c7817edaedfc96788d99 Mon Sep 17 00:00:00 2001
From: Simon Ser <contact@emersion.fr>
Date: Sat, 4 Dec 2021 17:22:36 +0100
Subject: [PATCH] lib/client: add generic error handling to roundtrip()

---
 lib/client.js | 86 +++++++++++++++++++++++++++------------------------
 lib/irc.js    |  4 +++
 2 files changed, 50 insertions(+), 40 deletions(-)

diff --git a/lib/client.js b/lib/client.js
index 894e991..c5c6652 100644
--- a/lib/client.js
+++ b/lib/client.js
@@ -52,10 +52,11 @@ let lastWhoxToken = 0;
 class IRCError extends Error {
 	constructor(msg) {
 		let text;
-		if (irc.isError(msg.command) && msg) {
+		if (msg.params.length > 0) {
+			// IRC errors have a human-readable message as last param
 			text = msg.params[msg.params.length - 1];
 		} else {
-			text = `unknown error (${msg.command} ${msg.params.join(" ")})`;
+			text = `unknown error (${msg.command})`;
 		}
 		super(text);
 
@@ -717,6 +718,8 @@ export default class Client extends EventTarget {
 	/* Execute a command that expects a response. `done` is called with message
 	 * events until it returns a truthy value. */
 	roundtrip(msg, done) {
+		let cmd = msg.command;
+
 		let label;
 		if (this.enabledCaps["labeled-response"]) {
 			lastLabel++;
@@ -735,6 +738,24 @@ export default class Client extends EventTarget {
 					return;
 				}
 
+				let isError = false;
+				switch (msg.command) {
+				case "FAIL":
+					isError = msg.params[0] === cmd;
+					break;
+				case irc.ERR_UNKNOWNERROR:
+				case irc.ERR_UNKNOWNCOMMAND:
+				case irc.ERR_NEEDMOREPARAMS:
+				case irc.RPL_TRYAGAIN:
+					isError = msg.params[1] === cmd;
+					break;
+				}
+				if (isError) {
+					removeEventListeners();
+					reject(new IRCError(msg));
+					return;
+				}
+
 				let result;
 				try {
 					result = done(msg);
@@ -784,23 +805,18 @@ export default class Client extends EventTarget {
 				}
 			}
 
-			switch (msg.command) {
-			case "BATCH":
-				let enter = msg.params[0].startsWith("+");
-				let name = msg.params[0].slice(1);
-				if (enter && msg.params[1] === batchType) {
-					batchName = name;
-					break;
-				}
-				if (!enter && name === batchName) {
-					return { ...this.batches.get(name), messages };
-				}
-				break;
-			case "FAIL":
-				if (msg.params[0] === cmd) {
-					throw new IRCError(msg);
-				}
-				break;
+			if (msg.command !== "BATCH") {
+				return;
+			}
+
+			let enter = msg.params[0].startsWith("+");
+			let name = msg.params[0].slice(1);
+			if (enter && msg.params[1] === batchType) {
+				batchName = name;
+				return;
+			}
+			if (!enter && name === batchName) {
+				return { ...this.batches.get(name), messages };
 			}
 		});
 	}
@@ -950,20 +966,15 @@ export default class Client extends EventTarget {
 			params: ["*", email || "*", password],
 		};
 		return this.roundtrip(msg, (msg) => {
-			switch (msg.command) {
-			case "REGISTER":
-				let result = msg.params[0];
-				return {
-					verificationRequired: result === "VERIFICATION_REQUIRED",
-					account: msg.params[1],
-					message: msg.params[2],
-				};
-			case "FAIL":
-				if (msg.params[0] === "REGISTER") {
-					throw new IRCError(msg);
-				}
-				break;
+			if (msg.command !== "REGISTER") {
+				return;
 			}
+			let result = msg.params[0];
+			return {
+				verificationRequired: result === "VERIFICATION_REQUIRED",
+				account: msg.params[1],
+				message: msg.params[2],
+			};
 		});
 	}
 
@@ -973,15 +984,10 @@ export default class Client extends EventTarget {
 			params: [account, code],
 		};
 		return this.roundtrip(msg, (msg) => {
-			switch (msg.command) {
-			case "VERIFY":
-				return { message: msg.params[2] };
-			case "FAIL":
-				if (msg.params[0] === "VERIFY") {
-					throw new IRCError(msg);
-				}
-				break;
+			if (msg.command !== "VERIFY") {
+				return;
 			}
+			return { message: msg.params[2] };
 		});
 	}
 }
diff --git a/lib/irc.js b/lib/irc.js
index 360b817..db130d5 100644
--- a/lib/irc.js
+++ b/lib/irc.js
@@ -5,6 +5,7 @@ export const RPL_CREATED = "003";
 export const RPL_MYINFO = "004";
 export const RPL_ISUPPORT = "005";
 export const RPL_UMODEIS = "221";
+export const RPL_TRYAGAIN = "263";
 export const RPL_AWAY = "301";
 export const RPL_WHOISUSER = "311";
 export const RPL_WHOISSERVER = "312";
@@ -31,11 +32,14 @@ export const RPL_ENDOFBANLIST = "368";
 export const RPL_MOTD = "372";
 export const RPL_MOTDSTART = "375";
 export const RPL_ENDOFMOTD = "376";
+export const ERR_UNKNOWNERROR = "400";
 export const ERR_NOSUCHNICK = "401";
+export const ERR_UNKNOWNCOMMAND = "421";
 export const ERR_NOMOTD = "422";
 export const ERR_ERRONEUSNICKNAME = "432";
 export const ERR_NICKNAMEINUSE = "433";
 export const ERR_NICKCOLLISION = "436";
+export const ERR_NEEDMOREPARAMS = "461";
 export const ERR_NOPERMFORHOST = "463";
 export const ERR_PASSWDMISMATCH = "464";
 export const ERR_YOUREBANNEDCREEP = "465";