Add missing pieces for 'driver' support on macOS (#34376)

- Adds desktop projects to ApplicationPackageStore
- Plumbs target overrides through the macOS build

packages/flutter_tools/lib/src/application_package.dart

@@ -395,6 +395,9 @@ class ApplicationPackageStore {
   AndroidApk android;
   IOSApp iOS;
   FuchsiaApp fuchsia;
+  LinuxApp linux;
+  MacOSApp macOS;
+  WindowsApp windows;
 
   Future<ApplicationPackage> getPackageForPlatform(TargetPlatform platform) async {
     switch (platform) {
@@ -411,8 +414,14 @@ class ApplicationPackageStore {
         fuchsia ??= FuchsiaApp.fromFuchsiaProject(FlutterProject.current().fuchsia);
         return fuchsia;
       case TargetPlatform.darwin_x64:
+        macOS ??= MacOSApp.fromMacOSProject(FlutterProject.current().macos);
+        return macOS;
       case TargetPlatform.linux_x64:
+        linux ??= LinuxApp.fromLinuxProject(FlutterProject.current().linux);
+        return linux;
       case TargetPlatform.windows_x64:
+        windows ??= WindowsApp.fromWindowsProject(FlutterProject.current().windows);
+        return windows;
       case TargetPlatform.tester:
       case TargetPlatform.web_javascript:
         return null;

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

@@ -16,6 +16,7 @@ import 'build.dart';
 /// A command to build a macos desktop target through a build shell script.
 class BuildMacosCommand extends BuildSubCommand {
   BuildMacosCommand() {
+    usesTargetOption();
     argParser.addFlag('debug',
       negatable: false,
       help: 'Build a debug version of your app.',
@@ -59,7 +60,11 @@ class BuildMacosCommand extends BuildSubCommand {
     if (!flutterProject.macos.existsSync()) {
       throwToolExit('No macOS desktop project configured.');
     }
-    await buildMacOS(flutterProject, buildInfo);
+    await buildMacOS(
+      flutterProject: flutterProject,
+      buildInfo: buildInfo,
+      targetOverride: targetFile,
+    );
     return null;
   }
 }

packages/flutter_tools/lib/src/macos/build_macos.dart

@@ -15,10 +15,13 @@ import '../project.dart';
 import '../usage.dart';
 import 'cocoapod_utils.dart';
 
-/// Builds the macOS project through xcode build.
-// TODO(jonahwilliams): support target option.
+/// Builds the macOS project through xcodebuild.
 // TODO(jonahwilliams): refactor to share code with the existing iOS code.
-Future<void> buildMacOS(FlutterProject flutterProject, BuildInfo buildInfo) async {
+Future<void> buildMacOS({
+  FlutterProject flutterProject,
+  BuildInfo buildInfo,
+  String targetOverride,
+}) async {
   final Directory flutterBuildDir = fs.directory(getMacOSBuildDirectory());
   if (!flutterBuildDir.existsSync()) {
     flutterBuildDir.createSync(recursive: true);
@@ -27,6 +30,7 @@ Future<void> buildMacOS(FlutterProject flutterProject, BuildInfo buildInfo) asyn
   await updateGeneratedXcodeProperties(
     project: flutterProject,
     buildInfo: buildInfo,
+    targetOverride: targetOverride,
     useMacOSConfig: true,
     setSymroot: false,
   );

packages/flutter_tools/lib/src/macos/macos_device.dart

@@ -75,7 +75,11 @@ class MacOSDevice extends Device {
     // Stop any running applications with the same executable.
     if (!prebuiltApplication) {
       Cache.releaseLockEarly();
-      await buildMacOS(FlutterProject.current(), debuggingOptions?.buildInfo);
+      await buildMacOS(
+        flutterProject: FlutterProject.current(),
+        buildInfo: debuggingOptions?.buildInfo,
+        targetOverride: mainPath,
+      );
     }
 
     // Ensure that the executable is locatable.

packages/flutter_tools/test/commands/build_macos_test.dart

@@ -63,6 +63,7 @@ void main() {
     applyMocksToCommand(command);
     fs.file('pubspec.yaml').createSync();
     fs.file('.packages').createSync();
+    fs.file(fs.path.join('lib', 'main.dart')).createSync(recursive: true);
 
     expect(createTestCommandRunner(command).run(
       const <String>['build', 'macos']
@@ -78,6 +79,7 @@ void main() {
     fs.directory('macos').createSync();
     fs.file('pubspec.yaml').createSync();
     fs.file('.packages').createSync();
+    fs.file(fs.path.join('lib', 'main.dart')).createSync(recursive: true);
     final FlutterProject flutterProject = FlutterProject.fromDirectory(fs.currentDirectory);
     final Directory flutterBuildDir = fs.directory(getMacOSBuildDirectory());