Add a --dart-entrypoint-args flag to flutter run to pass through Dart entrypoint arguments on Flutter Desktop (#69607)

packages/flutter_tools/lib/src/commands/run.dart

@@ -115,7 +115,14 @@ abstract class RunCommandBase extends FlutterCommand with DeviceBasedDevelopment
         help: 'Filters out all trace events except those that are specified in '
             'this comma separated list of allowed prefixes.',
         valueHelp: 'foo,bar',
-      );
+      )
+      ..addMultiOption('dart-entrypoint-args',
+        abbr: 'a',
+        help: 'Pass a list of arguments to the Dart entrypoint at application '
+              'startup. By default this is main(List<String> args). Specify '
+              'this option multiple times each with one argument to pass '
+              'multiple arguments to the Dart entrypoint. Currently this is '
+              'only supported on desktop platforms.');
     usesWebOptions(hide: !verboseHelp);
     usesTargetOption();
     usesPortOptions();
@@ -153,6 +160,7 @@ abstract class RunCommandBase extends FlutterCommand with DeviceBasedDevelopment
     if (buildInfo.mode.isRelease) {
       return DebuggingOptions.disabled(
         buildInfo,
+        dartEntrypointArgs: stringsArg('dart-entrypoint-args'),
         hostname: featureFlags.isWebEnabled ? stringArg('web-hostname') : '',
         port: featureFlags.isWebEnabled ? stringArg('web-port') : '',
         webUseSseForDebugProxy: featureFlags.isWebEnabled && stringArg('web-server-debug-protocol') == 'sse',
@@ -167,6 +175,7 @@ abstract class RunCommandBase extends FlutterCommand with DeviceBasedDevelopment
         startPaused: boolArg('start-paused'),
         disableServiceAuthCodes: boolArg('disable-service-auth-codes'),
         disableDds: boolArg('disable-dds'),
+        dartEntrypointArgs: stringsArg('dart-entrypoint-args'),
         dartFlags: stringArg('dart-flags') ?? '',
         useTestFonts: argParser.options.containsKey('use-test-fonts') && boolArg('use-test-fonts'),
         enableSoftwareRendering: argParser.options.containsKey('enable-software-rendering') && boolArg('enable-software-rendering'),

packages/flutter_tools/lib/src/desktop_device.dart

@@ -139,6 +139,7 @@ abstract class DesktopDevice extends Device {
     final Process process = await _processManager.start(
       <String>[
         executable,
+        ...?debuggingOptions?.dartEntrypointArgs,
       ],
       environment: _computeEnvironment(debuggingOptions, traceStartup, route),
     );

packages/flutter_tools/lib/src/device.dart

@@ -835,6 +835,7 @@ class DebuggingOptions {
     this.startPaused = false,
     this.disableServiceAuthCodes = false,
     this.disableDds = false,
+    this.dartEntrypointArgs = const <String>[],
     this.dartFlags = '',
     this.enableSoftwareRendering = false,
     this.skiaDeterministicRendering = false,
@@ -865,6 +866,7 @@ class DebuggingOptions {
    }) : debuggingEnabled = true;
 
   DebuggingOptions.disabled(this.buildInfo, {
+      this.dartEntrypointArgs = const <String>[],
       this.port,
       this.hostname,
       this.webEnableExposeUrl,
@@ -902,6 +904,7 @@ class DebuggingOptions {
   final BuildInfo buildInfo;
   final bool startPaused;
   final String dartFlags;
+  final List<String> dartEntrypointArgs;
   final bool disableServiceAuthCodes;
   final bool disableDds;
   final bool enableSoftwareRendering;

packages/flutter_tools/test/general.shard/desktop_device_test.dart

@@ -247,6 +247,29 @@ void main() {
 
     expect(device.createDevFSWriter(null, ''), isA<LocalDevFSWriter>());
   });
+
+  testWithoutContext('startApp supports dartEntrypointArgs', () async {
+    final Completer<void> completer = Completer<void>();
+    final FakeProcessManager processManager = FakeProcessManager.list(<FakeCommand>[
+      FakeCommand(
+        command: const <String>['debug', 'arg1', 'arg2'],
+        stdout: 'Observatory listening on http://127.0.0.1/0\n',
+        completer: completer
+      ),
+    ]);
+    final FakeDesktopDevice device = setUpDesktopDevice(processManager: processManager);
+    final FakeApplicationPackage package = FakeApplicationPackage();
+    final LaunchResult result = await device.startApp(
+      package,
+      prebuiltApplication: true,
+      debuggingOptions: DebuggingOptions.enabled(
+        BuildInfo.debug,
+        dartEntrypointArgs: <String>['arg1', 'arg2']
+      ),
+    );
+
+    expect(result.started, true);
+  });
 }
 
 FakeDesktopDevice setUpDesktopDevice({