[flutter_tools] support trailing args (#86431)

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

@@ -249,9 +249,8 @@ class PackagesForwardCommand extends FlutterCommand {
 }
 
 class PackagesPassthroughCommand extends FlutterCommand {
-  PackagesPassthroughCommand() {
-    requiresPubspecYaml();
-  }
+  @override
+  ArgParser argParser = ArgParser.allowAnything();
 
   @override
   String get name => 'pub';

packages/flutter_tools/lib/src/runner/flutter_command.dart

@@ -159,7 +159,6 @@ abstract class FlutterCommand extends Command<void> {
   @override
   ArgParser get argParser => _argParser;
   final ArgParser _argParser = ArgParser(
-    allowTrailingOptions: false,
     usageLineLength: globals.outputPreferences.wrapText ? globals.outputPreferences.wrapColumn : null,
   );
 

packages/flutter_tools/test/commands.shard/permeable/create_test.dart

@@ -1620,19 +1620,6 @@ void main() {
     );
   });
 
-  // Verify that we help the user correct an option ordering issue
-  testUsingContext('produces sensible error message', () async {
-    Cache.flutterRoot = '../..';
-
-    final CreateCommand command = CreateCommand();
-    final CommandRunner<void> runner = createTestCommandRunner(command);
-
-    expect(
-      runner.run(<String>['create', projectDir.path, '--pub']),
-      throwsToolExit(exitCode: 2, message: 'Try moving --pub'),
-    );
-  });
-
   testUsingContext('fails when file exists where output directory should be', () async {
     Cache.flutterRoot = '../..';
     final CreateCommand command = CreateCommand();

packages/flutter_tools/test/integration.shard/command_output_test.dart

@@ -247,4 +247,19 @@ void main() {
       'A crash report has been written to',
     ));
   });
+
+  testWithoutContext('flutter supports trailing args', () async {
+    final String flutterBin = fileSystem.path.join(getFlutterRoot(), 'bin', 'flutter');
+    final String helloWorld = fileSystem.path.join(getFlutterRoot(), 'examples', 'hello_world');
+    final ProcessResult result = await processManager.run(<String>[
+      flutterBin,
+      'test',
+      'test/hello_test.dart',
+      '-r',
+      'json',
+    ], workingDirectory: helloWorld);
+
+    expect(result.exitCode, 0);
+    expect(result.stderr, isEmpty);
+  });
 }