feat: ✨ Add self updating for standalone executable

Copied from eea905e3fe9a7b1507af0fac27939e73417db76a of meiszwflz/LemLink

Author: meisZWFLZ

config.json

@@ -0,0 +1,3 @@
+{
+  "standalone": true
+}

src/main.ts

@@ -1,7 +1,20 @@
-var argv = require('yargs/yargs')(process.argv.slice(2)).argv;
+import yargs from "yargs";
+import { standalone } from "../config.json";
+import { SelfUpdateUtility } from "./update";
 
-if (argv.ships > 3 && argv.distance < 53.5) {
-    console.log('Plunder more riffiwobbles!');
-} else {
-    console.log('Retreat from the xupptumblers!');
-}
+if (standalone) SelfUpdateUtility.init();
+
+yargs(process.argv.slice(2)).command(
+  "update",
+  "update",
+  {
+    url: {
+      alias: "u",
+      describe: "the URL to download the new executable from",
+    },
+  },
+  async (argv) => {
+    if (typeof argv.url === "string")
+      await SelfUpdateUtility.get().updateCLI(argv.url);
+  },
+);

src/update.ts

@@ -0,0 +1,117 @@
+import { renameSync, unlinkSync, createWriteStream, existsSync } from "fs";
+import child_process = require("child_process");
+import { get as httpGet, type IncomingMessage } from "http";
+import { standalone } from "../config.json";
+
+/**
+ * self updates the cli executable
+ * @warning DO NOT USE THIS IF NOT PART OF STANDALONE EXECUTABLE
+ */
+export class SelfUpdateUtility {
+  /**
+   * So how the heck does this CLI update itself?
+   *
+   * 1. Attempt to download new executable from downloadUrl to newPath
+   * 2. Rename current executable to oldPath
+   * 3. Rename newly downloaded executable to filePath
+   * 4. On startup of the cli, we attempt to remove oldPath
+   */
+
+  protected readonly filePath: string; // normal executable path
+  protected readonly newPath: string; // the new executable that will be downloaded
+  protected readonly oldPath: string;
+
+  private static singleton?: SelfUpdateUtility;
+  /**
+   * self updates the cli executable
+   * @warning DO NOT USE THIS IF NOT PART OF STANDALONE EXECUTABLE
+   */
+  private constructor() {
+    if (!standalone)
+      throw new Error(
+        "LemLink is not part of a standalone executable, and thus cannot self update",
+      );
+    const nodeExecutablePath = process.env._;
+    if (nodeExecutablePath === undefined) {
+      throw new Error("Could not find node executable path");
+    }
+
+    this.filePath = nodeExecutablePath;
+    this.newPath = this.filePath + "-new";
+    this.oldPath = this.filePath + "-old";
+
+    this.attemptToDeleteOldPathFile();
+  }
+
+  /**
+   * Should be run at the start of CLI program
+   */
+  public static init(): void {
+    if (this.singleton !== undefined) {
+      console.error(
+        "Self Update Utility has already been initialized, canceling init..",
+      );
+      return;
+    }
+    this.singleton = new SelfUpdateUtility();
+  }
+
+  public static get(): SelfUpdateUtility {
+    if (this.singleton === undefined)
+      throw new Error(
+        "Self Update Utility was not initialized at the start of CLI program!!",
+      );
+    return this.singleton;
+  }
+
+  /**
+   * @returns true if oldPath exists, false if otherwise
+   */
+  private attemptToDeleteOldPathFile(): boolean {
+    if (existsSync(this.oldPath)) {
+      unlinkSync(this.oldPath);
+      return true;
+    }
+    return false;
+  }
+
+  /**
+   * Replaces the current CLI executable with the one found at {@link downloadUrl}
+   * @param downloadUrl url from which a new executable should be downloaded
+   */
+  public async updateCLI(downloadUrl: string): Promise<void> {
+    /**
+     * See top of this file for info on how this works
+     */
+    console.log("Downloading new file...");
+    const fileStream = createWriteStream(this.newPath);
+
+    const response = await new Promise<IncomingMessage>((resolve) =>
+      httpGet(downloadUrl, resolve),
+    );
+
+    response.pipe(fileStream);
+    await new Promise((resolve) => fileStream.on("finish", resolve));
+    fileStream.close();
+
+    console.log("File downloaded successfully.");
+
+    console.log("Replacing current file...");
+    renameSync(this.filePath, this.oldPath);
+    renameSync(this.newPath, this.filePath);
+    console.log("Replaced current file successfully!");
+
+    console.log("Restarting...");
+    child_process.spawn(
+      // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+      process.argv.shift()!,
+      process.argv,
+      {
+        cwd: process.cwd(),
+        detached: true,
+        stdio: "inherit",
+        shell: true,
+      },
+    );
+  }
+}

tsconfig.json

@@ -41,7 +41,7 @@
     // "resolvePackageJsonExports": true,                /* Use the package.json 'exports' field when resolving package imports. */
     // "resolvePackageJsonImports": true,                /* Use the package.json 'imports' field when resolving imports. */
     // "customConditions": [],                           /* Conditions to set in addition to the resolver-specific defaults when resolving imports. */
-    // "resolveJsonModule": true,                        /* Enable importing .json files. */
+    "resolveJsonModule": true,                        /* Enable importing .json files. */
     // "allowArbitraryExtensions": true,                 /* Enable importing files with any extension, provided a declaration file is present. */
     // "noResolve": true,                                /* Disallow 'import's, 'require's or '<reference>'s from expanding the number of files TypeScript should add to a project. */