Add a dt run command with better stdout handling

CONTRIBUTING.md

@@ -169,10 +169,20 @@ dependency_overrides:
     path: relative/path/to/devtools/packages/devtools_shared
 ```
 
-Then you can run DevTools with the server by running the following from the top-level `devtools` directory:
-```
-dt serve
-```
+Then you can run DevTools with the server by running the following from anywhere under the `devtools/` directory:
+1. To run DevTools in release mode, served with the DevTools server (this emulates the production environment):
+	```
+	dt serve
+	```
+2. To run DevTools in debug mode with full debugging support and a connection to a live DevTools server:
+	```sh
+	dt run
+	```
+
+Option 2 is useful for a quicker development cycle. The DevTools build time will be faster, and you will be
+able to connect the DevTools web app to an IDE or DevTools for debugging purposes.
+
+To see the full list of arguments available for either command, please pass the `-h` flag.
 
 ### DevTools + VS Code integration (IDE-embedded DevTools experience)
 
@@ -191,7 +201,10 @@ command palette (`F1`)) and add the following to your settings:
 		"LOCAL_DART_SDK": "/path/to/sdk"
 		// Path to the version that Flutter DevTools is pinned to.
 		"FLUTTER_ROOT": "/path/to/devtools/tool/flutter-sdk"
-	}
+	},
+	"args": [
+		// Arguments that will be passed along to the `dt serve` command.
+    ],
 },
 ```
 

packages/devtools_app/lib/src/shared/preferences/preferences.dart

@@ -211,9 +211,9 @@ class PreferencesController extends DisposableController
       return;
     }
 
-    // Whether DevTools was run using the `dt serve --run-app` command, which
-    // runs DevTools in debug mode using `flutter run` and connects it to an
-    // instance of the DevTools server.
+    // Whether DevTools was run using the `dt run` command, which runs DevTools
+    // using `flutter run` and connects it to a locally running instance of the
+    // DevTools server.
     final usingDebugDevToolsServer =
         (const String.fromEnvironment('debug_devtools_server')).isNotEmpty &&
         !kReleaseMode;

packages/devtools_app/lib/src/shared/server/server.dart

@@ -47,9 +47,8 @@ String get devToolsServerUriAsString {
     _debugDevToolsServerFlag,
   );
   // Ensure we only use the debug DevTools server URI in non-release
-  // builds. By running `dt serve --run-app`, an instance of DevTools ran
-  // with `flutter run` can be connected to the DevTools server on a
-  // different port.
+  // builds. By running `dt run`, an instance of DevTools run with `flutter run`
+  // can be connected to the DevTools server on a different port.
   return debugDevToolsServerUriAsString.isNotEmpty && !kReleaseMode
       ? debugDevToolsServerUriAsString
       : Uri.base.toString();

tool/lib/commands/build.dart

@@ -16,23 +16,23 @@ import '../utils.dart';
 ///
 /// By default, this command builds DevTools in release mode, but this can be
 /// overridden by passing 'debug' or 'profile' as the
-/// [BuildCommandArgs.buildMode] argument. For testing embedded content in
+/// [SharedCommandArgs.buildMode] argument. For testing embedded content in
 /// VS Code, 'profile' or the default 'release' mode must be used because
 /// the '--dart2js-optimization=O1' flag that is passed for 'debug' builds
 /// will cause issues with the VS Code embedding.
 ///
-/// If the [BuildCommandArgs.useFlutterFromPath] argument is present, the
+/// If the [SharedCommandArgs.useFlutterFromPath] argument is present, the
 /// Flutter SDK will not be updated to the latest Flutter candidate before
 /// building DevTools. Use this flag to save the cost of updating the Flutter
 /// SDK when you already have the proper SDK checked out. This is helpful when
 /// developing with the DevTools server.
 ///
-/// If the [BuildCommandArgs.updatePerfetto] argument is present, the
+/// If the [SharedCommandArgs.updatePerfetto] argument is present, the
 /// precompiled bits for Perfetto will be updated from the
 /// `dt update-perfetto` command as part of the DevTools build
 /// process.
 ///
-/// If [BuildCommandArgs.pubGet] argument is negated (e.g. --no-pub-get), then
+/// If [SharedCommandArgs.pubGet] argument is negated (e.g. --no-pub-get), then
 /// `dt pub-get --only-main` command will not be run before building
 /// the DevTools web app. Use this flag to save the cost of updating pub
 /// packages if your pub cahce does not need to be updated. This is helpful when
@@ -60,13 +60,13 @@ class BuildCommand extends Command {
     final processManager = ProcessManager();
     final results = argResults!;
     final updateFlutter =
-        results[BuildCommandArgs.updateFlutter.flagName] as bool;
+        results[SharedCommandArgs.updateFlutter.flagName] as bool;
     final updatePerfetto =
-        results[BuildCommandArgs.updatePerfetto.flagName] as bool;
-    final runPubGet = results[BuildCommandArgs.pubGet.flagName] as bool;
-    final buildMode = results[BuildCommandArgs.buildMode.flagName] as String;
-    final useWasm = results[BuildCommandArgs.wasm.flagName] as bool;
-    final noStripWasm = results[BuildCommandArgs.noStripWasm.flagName] as bool;
+        results[SharedCommandArgs.updatePerfetto.flagName] as bool;
+    final runPubGet = results[SharedCommandArgs.pubGet.flagName] as bool;
+    final buildMode = results[SharedCommandArgs.buildMode.flagName] as String;
+    final useWasm = results[SharedCommandArgs.wasm.flagName] as bool;
+    final noStripWasm = results[SharedCommandArgs.noStripWasm.flagName] as bool;
 
     final webBuildDir = Directory(
       path.join(repo.devtoolsAppDirectoryPath, 'build', 'web'),
@@ -103,8 +103,8 @@ class BuildCommand extends Command {
           'web',
           '--source-maps',
           if (useWasm) ...[
-            BuildCommandArgs.wasm.asArg(),
-            if (noStripWasm) BuildCommandArgs.noStripWasm.asArg(),
+            SharedCommandArgs.wasm.asArg(),
+            if (noStripWasm) SharedCommandArgs.noStripWasm.asArg(),
           ] else ...[
             '--web-renderer',
             'canvaskit',

tool/lib/commands/run.dart

@@ -0,0 +1,43 @@
+// Copyright 2024 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'package:args/command_runner.dart';
+import 'package:devtools_tool/commands/shared.dart';
+import 'package:io/io.dart';
+
+import '../utils.dart';
+
+/// Runs the DevTools web app in debug mode with `flutter run` and connects it
+/// to a locally running instance of the DevTools server.
+/// 
+/// To open a debug connection to the DevTools server, pass the `--debug-server`
+/// flag to this command.
+class RunCommand extends Command {
+  RunCommand() {
+    argParser.addDebugServerFlag();
+  }
+
+  @override
+  String get name => 'run';
+
+  @override
+  String get description =>
+      'Runs the DevTools web app in debug mode using "flutter run" and connects'
+      ' it to a locally running instance of the DevTools server.';
+
+  @override
+  Future run() async {
+    final processManager = ProcessManager();
+    final process = await processManager.runProcess(
+      CliCommand.tool([
+        'serve',
+        SharedCommandArgs.runApp.asArg(),
+        ...argResults!.arguments,
+      ]),
+    );
+    if (process.exitCode == 1) {
+      throw Exception('Something went wrong while running `dt run`.');
+    }
+  }
+}