Merge pull request #2329 from chinmaygarde/master

iOS Simulator: Attempt 'sideloading' the updated Flutter application if the application runner is already up

bin/cache/engine.version

-3a48f9c90b6406b10d5a8a1897c147c71ccc59ba
+d474e9d2b60a9cb111c09844c10081b68bde9252

packages/flutter_tools/lib/src/ios/simulators.dart

@@ -14,6 +14,7 @@ import '../base/context.dart';
 import '../base/process.dart';
 import '../build_configuration.dart';
 import '../device.dart';
+import '../flx.dart' as flx;
 import '../globals.dart';
 import '../toolchain.dart';
 import 'mac.dart';
@@ -314,32 +315,20 @@ class IOSSimulator extends Device {
     int debugPort: observatoryDefaultPort,
     Map<String, dynamic> platformArgs
   }) async {
-    // TODO(chinmaygarde): Use mainPath, route.
     printTrace('Building ${app.name} for $id.');
 
     if (clearLogs)
       this.clearLogs();
 
-    // Step 1: Build the Xcode project.
-    bool buildResult = await buildIOSXcodeProject(app, buildForDevice: false);
-    if (!buildResult) {
-      printError('Could not build the application for the simulator.');
-      return false;
-    }
-
-    // Step 2: Assert that the Xcode project was successfully built.
-    Directory bundle = new Directory(path.join(app.localPath, 'build', 'Release-iphonesimulator', 'Runner.app'));
-    bool bundleExists = await bundle.exists();
-    if (!bundleExists) {
-      printError('Could not find the built application bundle at ${bundle.path}.');
+    if(!(await _setupUpdatedApplicationBundle(app, toolchain)))
       return false;
-    }
-
-    // Step 3: Install the updated bundle to the simulator.
-    SimControl.instance.install(id, path.absolute(bundle.path));
 
-    // Step 4: Prepare launch arguments.
-    List<String> args = <String>[];
+    // Prepare launch arguments.
+    List<String> args = <String>[
+      "--flx=${path.absolute(path.join('build', 'app.flx'))}",
+      "--dart-main=${path.absolute(mainPath)}",
+      "--package-root=${path.absolute('packages')}",
+    ];
 
     if (checked)
       args.add("--enable-checked-mode");
@@ -350,7 +339,7 @@ class IOSSimulator extends Device {
     if (debugPort != observatoryDefaultPort)
       args.add("--observatory-port=$debugPort");
 
-    // Step 5: Launch the updated application in the simulator.
+    // Launch the updated application in the simulator.
     try {
       SimControl.instance.launch(id, app.id, args);
     } catch (error) {
@@ -363,6 +352,57 @@ class IOSSimulator extends Device {
     return true;
   }
 
+  bool _applicationIsInstalledAndRunning(ApplicationPackage app) {
+    bool isInstalled = exitsHappy([
+      'xcrun',
+      'simctl',
+      'get_app_container',
+      'booted',
+      app.id,
+    ]);
+
+    bool isRunning = exitsHappy([
+      '/usr/bin/killall',
+      'Runner',
+    ]);
+
+    return isInstalled && isRunning;
+  }
+
+  Future<bool> _setupUpdatedApplicationBundle(ApplicationPackage app, Toolchain toolchain) async {
+    if (_applicationIsInstalledAndRunning(app)) {
+      return _sideloadUpdatedAssetsForInstalledApplicationBundle(app, toolchain);
+    } else {
+      return _buildAndInstallApplicationBundle(app);
+    }
+  }
+
+  Future<bool> _buildAndInstallApplicationBundle(ApplicationPackage app) async {
+    // Step 1: Build the Xcode project.
+    bool buildResult = await buildIOSXcodeProject(app, buildForDevice: false);
+    if (!buildResult) {
+      printError('Could not build the application for the simulator.');
+      return false;
+    }
+
+    // Step 2: Assert that the Xcode project was successfully built.
+    Directory bundle = new Directory(path.join(app.localPath, 'build', 'Release-iphonesimulator', 'Runner.app'));
+    bool bundleExists = await bundle.exists();
+    if (!bundleExists) {
+      printError('Could not find the built application bundle at ${bundle.path}.');
+      return false;
+    }
+
+    // Step 3: Install the updated bundle to the simulator.
+    SimControl.instance.install(id, path.absolute(bundle.path));
+    return true;
+  }
+
+  Future<bool> _sideloadUpdatedAssetsForInstalledApplicationBundle(
+      ApplicationPackage app, Toolchain toolchain) async {
+    return (await flx.build(toolchain, precompiledSnapshot: true)) == 0;
+  }
+
   @override
   Future<bool> stopApp(ApplicationPackage app) async {
     // Currently we don't have a way to stop an app running on iOS.