Merge pull request #10530 from vector-im/t3chguy/electron_help

Add --help to electron app

electron_app/src/electron-main.js

@@ -23,7 +23,10 @@ limitations under the License.
 const checkSquirrelHooks = require('./squirrelhooks');
 if (checkSquirrelHooks()) return;
 
-const argv = require('minimist')(process.argv);
+const argv = require('minimist')(process.argv, {
+    alias: {help: "h"},
+});
+
 const {app, ipcMain, powerSaveBlocker, BrowserWindow, Menu, autoUpdater, protocol} = require('electron');
 const AutoLaunch = require('auto-launch');
 const path = require('path');
@@ -37,6 +40,19 @@ const { migrateFromOldOrigin } = require('./originMigrator');
 const windowStateKeeper = require('electron-window-state');
 const Store = require('electron-store');
 
+if (argv["help"]) {
+    console.log("Options:");
+    console.log("  --profile-dir {path}: Path to where to store the profile.");
+    console.log("  --profile {name}:     Name of alternate profile to use, allows for running multiple accounts.");
+    console.log("  --devtools:           Install and use react-devtools and react-perf.");
+    console.log("  --no-update:          Disable automatic updating.");
+    console.log("  --hidden:             Start the application hidden in the system tray.");
+    console.log("  --help:               Displays this help message.");
+    console.log("And more such as --proxy, see:" +
+        "https://github.com/electron/electron/blob/master/docs/api/chrome-command-line-switches.md");
+    app.exit();
+}
+
 // boolean flag set whilst we are doing one-time origin migration
 // We only serve the origin migration script while we're actually
 // migrating to mitigate any risk of it being used maliciously.