From 31b293fa0374ca31003e4bad970f4744a1d04389 Mon Sep 17 00:00:00 2001
From: Simon Ser <contact@emersion.fr>
Date: Mon, 6 Dec 2021 23:09:30 +0100
Subject: [PATCH] lib/client: use Error objects for error events

---
 components/app.js | 17 +++++++++++++++--
 lib/client.js     | 38 ++++++++++++++++----------------------
 2 files changed, 31 insertions(+), 24 deletions(-)

diff --git a/components/app.js b/components/app.js
index 5451bf3..6cbfbdc 100644
--- a/components/app.js
+++ b/components/app.js
@@ -317,8 +317,21 @@ export default class App extends Component {
 		}
 	}
 
-	showError(msg) {
-		this.setState({ error: String(msg) });
+	showError(err) {
+		console.error("App error: ", err);
+
+		let text;
+		if (err instanceof Error) {
+			let l = [];
+			while (err) {
+				l.push(err.message);
+				err = err.cause;
+			}
+			text = l.join(": ");
+		} else {
+			text = String(err);
+		}
+		this.setState({ error: text });
 		lastErrorID++;
 		return lastErrorID;
 	}
diff --git a/lib/client.js b/lib/client.js
index c4dac01..9c39ce7 100644
--- a/lib/client.js
+++ b/lib/client.js
@@ -126,7 +126,7 @@ export default class Client extends EventTarget {
 		} catch (err) {
 			console.error("Failed to create connection:", err);
 			setTimeout(() => {
-				this.dispatchEvent(new CustomEvent("error", { detail: "Failed to create connection: " + err }));
+				this.dispatchError(new Error("Failed to create connection", { cause: err }));
 				this.setStatus(Client.Status.DISCONNECTED);
 			}, 0);
 			return;
@@ -137,7 +137,7 @@ export default class Client extends EventTarget {
 			try {
 				this.handleMessage(event);
 			} catch (err) {
-				this.dispatchEvent(new CustomEvent("error", { detail: err }));
+				this.dispatchError(err);
 				this.disconnect();
 			}
 		});
@@ -146,7 +146,7 @@ export default class Client extends EventTarget {
 			console.log("Connection closed (code: " + event.code + ")");
 
 			if (event.code !== NORMAL_CLOSURE && event.code !== GOING_AWAY) {
-				this.dispatchEvent(new CustomEvent("error", { detail: "Connection error" }));
+				this.dispatchError(new Error("Connection error"));
 			}
 
 			this.ws = null;
@@ -202,6 +202,10 @@ export default class Client extends EventTarget {
 		this.dispatchEvent(new CustomEvent("status"));
 	}
 
+	dispatchError(err) {
+		this.dispatchEvent(new CustomEvent("error", { detail: err }));
+	}
+
 	handleOpen() {
 		console.log("Connection opened");
 		this.setStatus(Client.Status.REGISTERING);
@@ -264,7 +268,7 @@ export default class Client extends EventTarget {
 		switch (msg.command) {
 		case irc.RPL_WELCOME:
 			if (this.params.saslPlain && !this.supportsCap) {
-				this.dispatchEvent(new CustomEvent("error", { detail: "Server doesn't support SASL PLAIN" }));
+				this.dispatchError(new Error("Server doesn't support SASL PLAIN"));
 				this.disconnect();
 				return;
 			}
@@ -303,7 +307,7 @@ export default class Client extends EventTarget {
 			// Both PLAIN and EXTERNAL expect an empty challenge
 			let challengeStr = msg.params[0];
 			if (challengeStr != "+") {
-				this.dispatchEvent(new CustomEvent("error", { detail: "Expected an empty challenge, got: " + challengeStr }));
+				this.dispatchError(new Error("Expected an empty challenge, got: " + challengeStr));
 				this.send({ command: "AUTHENTICATE", params: ["*"] });
 			}
 			break;
@@ -362,9 +366,7 @@ export default class Client extends EventTarget {
 			}
 			break;
 		case "ERROR":
-			this.dispatchEvent(new CustomEvent("error", {
-				detail: "Fatal IRC error: " + msg.params[0],
-			}));
+			this.dispatchError(new IRCError(msg));
 			this.disconnect();
 			break;
 		case irc.ERR_PASSWDMISMATCH:
@@ -374,9 +376,7 @@ export default class Client extends EventTarget {
 		case irc.ERR_UNAVAILRESOURCE:
 		case irc.ERR_NOPERMFORHOST:
 		case irc.ERR_YOUREBANNEDCREEP:
-			this.dispatchEvent(new CustomEvent("error", {
-				detail: "Error (" + msg.command + "): " + msg.params[msg.params.length - 1],
-			}));
+			this.dispatchError(new IRCError(msg));
 			if (this.status != Client.Status.REGISTERED) {
 				this.disconnect();
 			}
@@ -387,15 +387,13 @@ export default class Client extends EventTarget {
 			}
 			let reason = msg.params[msg.params.length - 1];
 			if (msg.params[0] === "BOUNCER" && msg.params[2] === "BIND") {
-				this.dispatchEvent(new CustomEvent("error", {
-					detail: "Failed to bind to bouncer network: " + reason,
+				this.dispatchError(new Error("Failed to bind to bouncer network", {
+					cause: new IRCError(msg),
 				}));
 				this.disconnect();
 			}
 			if (msg.params[1] === "ACCOUNT_REQUIRED") {
-				this.dispatchEvent(new CustomEvent("error", {
-					detail: reason,
-				}));
+				this.dispatchError(new IRCError(msg));
 				this.disconnect();
 			}
 			break;
@@ -635,12 +633,8 @@ export default class Client extends EventTarget {
 					} else if (this.params.saslExternal) {
 						promise = this.authenticate("EXTERNAL");
 					}
-					(promise || Promise.resolve()).catch((msg) => {
-						if (msg.command) {
-							this.dispatchEvent(new CustomEvent("error", {
-								detail: "Authentication error (SASL " + msg.command + "): " + msg.params[1],
-							}));
-						}
+					(promise || Promise.resolve()).catch((err) => {
+						this.dispatchError(err);
 						this.disconnect();
 					});
 				}