[shelter] improve bundle fetching

this also fixes shelter failing to load when there's no internet connection right on launch

CHANGELOG.md

@@ -1,3 +1,6 @@
+## r18
+Improve shelter bundle fetching
+
 ## r17
  - Make the new dashboard look nicer
  - Replace useless last module time with cache hit rates

branches/mod/shelter/patch.js

@@ -1,14 +1,13 @@
 const electron = require("electron");
 const path = require("path");
 const Module = require("module");
-const fs = require("original-fs"); // using electron's fs causes app.asar to be locked during host updates
+const fs = require("original-fs"); // "fs" module without electron modifications
 const https = require("https");
 const { EOL } = require("os");
 
 const logger = new Proxy(console, {
 	get: (target, key) =>
 		function (...args) {
-			//logFile?.write(`[${new Date().toISOString()}] [${key}] ${args.join(" ")}${EOL}`);
 			return target[key].apply(console, ["[shelter]", ...args]);
 		},
 });
@@ -18,42 +17,63 @@ logger.log("Loading...");
 // #region Bundle
 const remoteUrl =
 	process.env.SHELTER_BUNDLE_URL || "https://raw.githubusercontent.com/uwu/shelter-builds/main/shelter.js";
-const localBundle = process.env.SHELTER_DIST_PATH;
+const distPath = process.env.SHELTER_DIST_PATH;
 
-let fetchPromise; // only fetch once
+let localBundle;
 
-if (!localBundle)
-	fetchPromise = new Promise((resolve, reject) => {
+if (distPath) {
+	localBundle =
+		fs.readFileSync(path.join(distPath, "shelter.js"), "utf8") +
+		`\n//# sourceMappingURL=file://${process.platform === "win32" ? "/" : ""}${path.join(distPath, "shelter.js.map")}`;
+}
+
+let remoteBundle;
+let remoteBundlePromise;
+
+const fetchRemoteBundleIfNeeded = () => {
+	if (localBundle || remoteBundle) return Promise.resolve();
+
+	remoteBundlePromise ??= new Promise((resolve) => {
 		const req = https.get(remoteUrl);
 
 		req.on("response", (res) => {
+			if (res.statusCode !== 200) {
+				remoteBundlePromise = null;
+				resolve();
+				return;
+			}
 			const chunks = [];
 
 			res.on("data", (chunk) => chunks.push(chunk));
 			res.on("end", () => {
-				let data = Buffer.concat(chunks).toString("utf-8");
+				let script = Buffer.concat(chunks).toString("utf-8");
 
-				if (!data.includes("//# sourceMappingURL=")) data += `\n//# sourceMappingURL=${remoteUrl + ".map"}`;
-
-				resolve(data);
+				if (!script.includes("//# sourceMappingURL=")) script += `\n//# sourceMappingURL=${remoteUrl + ".map"}`;
+				remoteBundle = script;
+				remoteBundlePromise = null;
+				resolve();
 			});
 		});
 
-		req.on("error", reject);
+		req.on("error", (e) => {
+			logger.error("Error fetching remote bundle:", e);
+			remoteBundlePromise = null;
+			resolve();
+		});
 
 		req.end();
 	});
 
-const getShelterBundle = () =>
-	!localBundle
-		? fetchPromise
-		: Promise.resolve(
-				fs.readFileSync(path.join(localBundle, "shelter.js"), "utf8") +
-					`\n//# sourceMappingURL=file://${process.platform === "win32" ? "/" : ""}${path.join(
-						localBundle,
-						"shelter.js.map",
-					)}`,
-			);
+	return remoteBundlePromise;
+};
+
+fetchRemoteBundleIfNeeded();
+
+const getShelterBundle = () => {
+	if (localBundle) return localBundle;
+	if (remoteBundle) return remoteBundle;
+	return `console.error("[shelter] Bundle could not be fetched in time. Aborting!");`;
+};
 // #endregion
 
 // #region IPC
@@ -157,5 +177,28 @@ Module.prototype.require = function (path) {
 	}
 	return loadedModule;
 };
+// #endregion
+
+// #region Patch BrowserWindow
+const ProxiedBrowserWindow = new Proxy(electron.BrowserWindow, {
+	construct(target, args) {
+		const window = new target(...args);
+		const originalLoadURL = window.loadURL;
+		window.loadURL = async function (url) {
+			if (url.includes("discord.com/app")) {
+				await fetchRemoteBundleIfNeeded();
+			}
+			return await originalLoadURL.apply(this, arguments);
+		};
+
+		return window;
+	},
+});
 
+const electronPath = require.resolve("electron");
+delete require.cache[electronPath].exports;
+require.cache[electronPath].exports = {
+	...electron,
+	BrowserWindow: ProxiedBrowserWindow,
+};
 // #endregion