Use source list from the compiler to track invalidated files for hot reload. (#29693)

* Use source list from the compiler to track invalidated files.

* Revert accidental change

* Fix first-time-seen-the-file logic

* Fix/simplify invalidate logic now that we can rely on compiler to let us know what is the cut-off point for invalidation.

* Update devfs mock to accommodate for new fields

* Fix deleted files case

* Analyzer found missing final

packages/flutter_tools/lib/src/android/android_device.dart

@@ -352,7 +352,6 @@ class AndroidDevice extends Device {
     DebuggingOptions debuggingOptions,
     Map<String, dynamic> platformArgs,
     bool prebuiltApplication = false,
-    bool applicationNeedsRebuild = false,
     bool usesTerminalUi = true,
     bool ipv6 = false,
   }) async {

packages/flutter_tools/lib/src/codegen.dart

@@ -214,7 +214,7 @@ class CodeGeneratingResidentCompiler implements ResidentCompiler {
   }
 
   @override
-  Future<CompilerOutput> recompile(String mainPath, List<String> invalidatedFiles, {String outputPath, String packagesFilePath}) async {
+  Future<CompilerOutput> recompile(String mainPath, List<Uri> invalidatedFiles, {String outputPath, String packagesFilePath}) async {
     if (_codegenDaemon.lastStatus != CodegenStatus.Succeeded && _codegenDaemon.lastStatus != CodegenStatus.Failed) {
       await _codegenDaemon.buildResults.firstWhere((CodegenStatus status) {
         return status == CodegenStatus.Succeeded || status == CodegenStatus.Failed;

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

@@ -306,7 +306,6 @@ class HotRunnerFactory {
     dillOutputPath: dillOutputPath,
     stayResident: stayResident,
     ipv6: ipv6,
-    flutterProject: flutterProject,
   );
 }
 

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

@@ -19,7 +19,6 @@ import '../convert.dart';
 import '../device.dart';
 import '../emulator.dart';
 import '../globals.dart';
-import '../project.dart';
 import '../resident_runner.dart';
 import '../run_cold.dart';
 import '../run_hot.dart';
@@ -342,8 +341,6 @@ class AppDomain extends Domain {
     if (await device.isLocalEmulator && !options.buildInfo.supportsEmulator) {
       throw '${toTitleCase(options.buildInfo.friendlyModeName)} mode is not supported for emulators.';
     }
-    final FlutterProject flutterProject = await FlutterProject.current();
-
     // We change the current working directory for the duration of the `start` command.
     final Directory cwd = fs.currentDirectory;
     fs.currentDirectory = fs.directory(projectDirectory);
@@ -370,7 +367,6 @@ class AppDomain extends Domain {
         dillOutputPath: dillOutputPath,
         ipv6: ipv6,
         hostIsIde: true,
-        flutterProject: flutterProject,
       );
     } else {
       runner = ColdRunner(

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

@@ -13,7 +13,6 @@ import '../cache.dart';
 import '../device.dart';
 import '../globals.dart';
 import '../ios/mac.dart';
-import '../project.dart';
 import '../resident_runner.dart';
 import '../run_cold.dart';
 import '../run_hot.dart';
@@ -281,7 +280,6 @@ class RunCommand extends RunCommandBase {
     // Enable hot mode by default if `--no-hot` was not passed and we are in
     // debug mode.
     final bool hotMode = shouldUseHotMode();
-    final FlutterProject flutterProject = await FlutterProject.current();
 
     writePidFile(argResults['pid-file']);
 
@@ -391,7 +389,6 @@ class RunCommand extends RunCommandBase {
         saveCompilationTrace: argResults['train'],
         stayResident: stayResident,
         ipv6: ipv6,
-        flutterProject: flutterProject,
       );
     } else {
       runner = ColdRunner(

packages/flutter_tools/lib/src/compile.dart

@@ -354,7 +354,7 @@ class _RecompileRequest extends _CompilationRequest {
   ) : super(completer);
 
   String mainPath;
-  List<String> invalidatedFiles;
+  List<Uri> invalidatedFiles;
   String outputPath;
   String packagesFilePath;
 
@@ -450,7 +450,7 @@ class ResidentCompiler {
   /// null is returned.
   Future<CompilerOutput> recompile(
     String mainPath,
-    List<String> invalidatedFiles, {
+    List<Uri> invalidatedFiles, {
     @required String outputPath,
     String packagesFilePath,
   }) async {
@@ -497,9 +497,9 @@ class ResidentCompiler {
         : '';
     _server.stdin.writeln('recompile $mainUri$inputKey');
     printTrace('<- recompile $mainUri$inputKey');
-    for (String fileUri in request.invalidatedFiles) {
-      _server.stdin.writeln(_mapFileUri(fileUri, packageUriMapper));
-      printTrace('<- ${_mapFileUri(fileUri, packageUriMapper)}');
+    for (Uri fileUri in request.invalidatedFiles) {
+      _server.stdin.writeln(_mapFileUri(fileUri.toString(), packageUriMapper));
+      printTrace('<- ${_mapFileUri(fileUri.toString(), packageUriMapper)}');
     }
     _server.stdin.writeln(inputKey);
     printTrace('<- $inputKey');

packages/flutter_tools/lib/src/devfs.dart

@@ -387,6 +387,8 @@ class DevFS {
   String _packagesFilePath;
   final Map<Uri, DevFSContent> _entries = <Uri, DevFSContent>{};
   final Set<String> assetPathsToEvict = <String>{};
+  List<Uri> sources = <Uri>[];
+  DateTime lastCompiled;
 
   Uri _baseUri;
   Uri get baseUri => _baseUri;
@@ -439,7 +441,7 @@ class DevFS {
     bool fullRestart = false,
     String projectRootPath,
     @required String pathToReload,
-    @required List<String> invalidatedFiles,
+    @required List<Uri> invalidatedFiles,
   }) async {
     assert(trackWidgetCreation != null);
     assert(generator != null);
@@ -478,6 +480,7 @@ class DevFS {
       generator.reset();
     }
     printTrace('Compiling dart to kernel with ${invalidatedFiles.length} updated files');
+    lastCompiled = DateTime.now();
     final CompilerOutput compilerOutput = await generator.recompile(
       mainPath,
       invalidatedFiles,
@@ -485,6 +488,7 @@ class DevFS {
       packagesFilePath : _packagesFilePath,
     );
     // list of sources that needs to be monitored are in [compilerOutput.sources]
+    sources = compilerOutput.sources;
     //
     // Don't send full kernel file that would overwrite what VM already
     // started loading from.

packages/flutter_tools/lib/src/device.dart

@@ -286,7 +286,6 @@ abstract class Device {
     DebuggingOptions debuggingOptions,
     Map<String, dynamic> platformArgs,
     bool prebuiltApplication = false,
-    bool applicationNeedsRebuild = false,
     bool usesTerminalUi = true,
     bool ipv6 = false,
   });

packages/flutter_tools/lib/src/fuchsia/fuchsia_device.dart

@@ -188,7 +188,6 @@ class FuchsiaDevice extends Device {
     DebuggingOptions debuggingOptions,
     Map<String, dynamic> platformArgs,
     bool prebuiltApplication = false,
-    bool applicationNeedsRebuild = false,
     bool usesTerminalUi = true,
     bool ipv6 = false,
   }) => Future<void>.error('unimplemented');

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

@@ -235,7 +235,6 @@ class IOSDevice extends Device {
     DebuggingOptions debuggingOptions,
     Map<String, dynamic> platformArgs,
     bool prebuiltApplication = false,
-    bool applicationNeedsRebuild = false,
     bool usesTerminalUi = true,
     bool ipv6 = false,
   }) async {

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

@@ -297,7 +297,6 @@ class IOSSimulator extends Device {
     DebuggingOptions debuggingOptions,
     Map<String, dynamic> platformArgs,
     bool prebuiltApplication = false,
-    bool applicationNeedsRebuild = false,
     bool usesTerminalUi = true,
     bool ipv6 = false,
   }) async {

packages/flutter_tools/lib/src/linux/linux_device.dart

@@ -57,7 +57,6 @@ class LinuxDevice extends Device {
     DebuggingOptions debuggingOptions,
     Map<String, dynamic> platformArgs,
     bool prebuiltApplication = false,
-    bool applicationNeedsRebuild = false,
     bool usesTerminalUi = true,
     bool ipv6 = false,
   }) {

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

@@ -63,7 +63,6 @@ class MacOSDevice extends Device {
     DebuggingOptions debuggingOptions,
     Map<String, dynamic> platformArgs,
     bool prebuiltApplication = false,
-    bool applicationNeedsRebuild = false,
     bool usesTerminalUi = true,
     bool ipv6 = false,
   }) async {

packages/flutter_tools/lib/src/resident_runner.dart

@@ -345,7 +345,6 @@ class FlutterDevice {
     startEchoingDeviceLog();
 
     // Start the application.
-    final bool hasDirtyDependencies = hotRunner.hasDirtyDependencies(this);
     final Future<LaunchResult> futureResult = device.startApp(
       package,
       mainPath: hotRunner.mainPath,
@@ -353,7 +352,6 @@ class FlutterDevice {
       platformArgs: platformArgs,
       route: route,
       prebuiltApplication: prebuiltMode,
-      applicationNeedsRebuild: shouldBuild || hasDirtyDependencies,
       usesTerminalUi: hotRunner.usesTerminalUI,
       ipv6: hotRunner.ipv6,
     );
@@ -409,7 +407,6 @@ class FlutterDevice {
 
     startEchoingDeviceLog();
 
-    final bool hasDirtyDependencies = coldRunner.hasDirtyDependencies(this);
     final LaunchResult result = await device.startApp(
       package,
       mainPath: coldRunner.mainPath,
@@ -417,7 +414,6 @@ class FlutterDevice {
       platformArgs: platformArgs,
       route: route,
       prebuiltApplication: prebuiltMode,
-      applicationNeedsRebuild: shouldBuild || hasDirtyDependencies,
       usesTerminalUi: coldRunner.usesTerminalUI,
       ipv6: coldRunner.ipv6,
     );
@@ -445,7 +441,7 @@ class FlutterDevice {
     bool fullRestart = false,
     String projectRootPath,
     String pathToReload,
-    @required List<String> invalidatedFiles,
+    @required List<Uri> invalidatedFiles,
   }) async {
     final Status devFSStatus = logger.startProgress(
       'Syncing files to device ${device.name}...',
@@ -942,26 +938,6 @@ abstract class ResidentRunner {
     return exitCode;
   }
 
-  bool hasDirtyDependencies(FlutterDevice device) {
-    if (device.package.packagesFile == null || !device.package.packagesFile.existsSync()) {
-      return true;
-    }
-    // why is this sometimes an APK.
-    if (!device.package.packagesFile.path.contains('.packages')) {
-      return true;
-    }
-    // Leave pubspec null to check all dependencies.
-    final ProjectFileInvalidator projectFileInvalidator = ProjectFileInvalidator(device.package.packagesFile.path, null);
-    projectFileInvalidator.findInvalidated();
-    final int lastBuildTime = device.package.packagesFile.statSync().modified.millisecondsSinceEpoch;
-    for (int updateTime in projectFileInvalidator.updateTime.values) {
-      if (updateTime > lastBuildTime) {
-        return true;
-      }
-    }
-    return false;
-  }
-
   Future<void> preStop() async { }
 
   Future<void> stopApp() async {

packages/flutter_tools/lib/src/run_hot.dart

@@ -7,7 +7,6 @@ import 'dart:async';
 import 'package:json_rpc_2/error_code.dart' as rpc_error_code;
 import 'package:json_rpc_2/json_rpc_2.dart' as rpc;
 import 'package:meta/meta.dart';
-import 'package:yaml/yaml.dart';
 
 import 'base/common.dart';
 import 'base/context.dart';
@@ -19,11 +18,9 @@ import 'base/utils.dart';
 import 'build_info.dart';
 import 'compile.dart';
 import 'convert.dart';
-import 'dart/package_map.dart';
 import 'devfs.dart';
 import 'device.dart';
 import 'globals.dart';
-import 'project.dart';
 import 'resident_runner.dart';
 import 'usage.dart';
 import 'vmservice.dart';
@@ -70,7 +67,6 @@ class HotRunner extends ResidentRunner {
     bool saveCompilationTrace = false,
     bool stayResident = true,
     bool ipv6 = false,
-    FlutterProject flutterProject,
   }) : super(devices,
              target: target,
              debuggingOptions: debuggingOptions,
@@ -79,19 +75,13 @@ class HotRunner extends ResidentRunner {
              packagesFilePath: packagesFilePath,
              saveCompilationTrace: saveCompilationTrace,
              stayResident: stayResident,
-             ipv6: ipv6)  {
-    fileInvalidator = ProjectFileInvalidator(
-      packagesFilePath ?? fs.path.absolute(PackageMap.globalPackagesPath),
-      flutterProject,
-    );
-  }
+             ipv6: ipv6);
 
   final bool benchmarkMode;
   final File applicationBinary;
   final bool hostIsIde;
   bool _didAttach = false;
   final String dillOutputPath;
-  ProjectFileInvalidator fileInvalidator;
 
   final Map<String, List<int>> benchmarkData = <String, List<int>>{};
   // The initial launch is from a snapshot.
@@ -322,7 +312,12 @@ class HotRunner extends ResidentRunner {
       if (result != 0)
         return UpdateFSReport(success: false);
     }
-    final List<String> invalidatedFiles = fileInvalidator.findInvalidated();
+
+    // Picking up first device's compiler as a source of truth - compilers
+    // for all devices should be in sync.
+    final List<Uri> invalidatedFiles = ProjectFileInvalidator.findInvalidated(
+      lastCompiled: flutterDevices[0].devFS.lastCompiled,
+      urisToMonitor: flutterDevices[0].devFS.sources);
     final UpdateFSReport results = UpdateFSReport(success: true);
     for (FlutterDevice device in flutterDevices) {
       results.incorporateResults(await device.updateDevFS(
@@ -941,104 +936,31 @@ class HotRunner extends ResidentRunner {
 }
 
 class ProjectFileInvalidator {
-  ProjectFileInvalidator(this._packagesPath, this._flutterProject) {
-    final File packagesFile = fs.file(_packagesPath);
-    if (packagesFile.existsSync()) {
-      _packagesUpdateTime = packagesFile.statSync().modified.millisecondsSinceEpoch;
-      _packageMap = PackageMap(_packagesPath).map;
-    } else {
-      _packagesUpdateTime = -1;
-      _packageMap = const <String, Uri>{};
-    }
-    _computePackageMap(_packageMap, _flutterProject);
-  }
-
-  // Used to avoid watching pubspec directories. This will not change even with pub upgrade,
-  // because that actually switches the directory and requires a corresponding
-  // update to .packages
   static const String _pubCachePathLinuxAndWindows = '.pub-cache';
   static const String _pubCachePathWindows = 'Pub/Cache';
 
-  Map<String, Uri> _packageMap;
-  final String _packagesPath;
-  final FlutterProject _flutterProject;
-  final Map<String, int> _updateTime = <String, int>{};
-  int _packagesUpdateTime;
-
-  Map<String, int> get updateTime => _updateTime;
-
-  @visibleForTesting
-  Map<String, Uri> get packageMap => _packageMap;
-
-  static void _computePackageMap(Map<String, Uri> packageMap, FlutterProject flutterProject) {
-    if (flutterProject != null && flutterProject.pubspecFile.existsSync()) {
-      try {
-        final YamlMap pubspec = loadYamlDocument(flutterProject.pubspecFile.readAsStringSync()).contents;
-        final YamlMap dependencies = pubspec['dependencies'];
-        final Set<String> relevantDependencies = Set<String>.from(dependencies.keys);
-        // Remove any packages which were tagged as dev dependenices,
-        // But don't remove the app itself!
-        for (String packageName in packageMap.keys.toList()) {
-          if (!relevantDependencies.contains(packageName) && packageName != flutterProject.manifest.appName) {
-            packageMap.remove(packageName);
-            continue;
-          }
-        }
-      } catch (err) {
-        // If we detect a pubspec formatting problem, fallback to the packages file.
+  static List<Uri> findInvalidated({@required DateTime lastCompiled,
+    @required List<Uri> urisToMonitor}) {
+    final List<Uri> invalidatedFiles = <Uri>[];
+    int scanned = 0;
+    final Stopwatch stopwatch = Stopwatch()..start();
+    for (Uri uri in urisToMonitor) {
+      if ((platform.isWindows && uri.path.contains(_pubCachePathWindows))
+          || uri.path.contains(_pubCachePathLinuxAndWindows)) {
+        // Don't watch pub cache directories to speed things up a little.
+        continue;
       }
-    }
-    // Remove any packages which are derived from the pub cache.
-    for (String packageName in packageMap.keys.toList()) {
-      final String path = packageMap[packageName].path;
-      if ((platform.isWindows && path.contains(_pubCachePathWindows))
-          || path.contains(_pubCachePathLinuxAndWindows)) {
-        packageMap.remove(packageName);
+      final DateTime updatedAt = fs.statSync(
+          uri.toFilePath(windows: platform.isWindows)).modified;
+      scanned++;
+      if (updatedAt == null) {
+        continue;
       }
-    }
-  }
-
-  List<String> findInvalidated() {
-    final File packagesFile = fs.file(_packagesPath);
-    if (packagesFile.existsSync()) {
-      final int newPackagesUpdateTime = packagesFile.statSync().modified.millisecondsSinceEpoch;
-      // Hot reloading with an updated package will often times kill a non-trivial
-      // appliction. This _might_ work, given certain application size and package
-      // constraints, so instead of exiting we print a warning so that the user has
-      // some hint on what went wrong.
-      if (newPackagesUpdateTime > _packagesUpdateTime) {
-        printError('Warning: updated dependencies detected. The Flutter application will require a restart to safely use new packages.');
+      if (updatedAt.millisecondsSinceEpoch > lastCompiled.millisecondsSinceEpoch) {
+        invalidatedFiles.add(uri);
       }
-      _packagesUpdateTime = newPackagesUpdateTime;
-    }
-    final List<String> invalidatedFiles = <String>[];
-    for (String packageName in _packageMap.keys) {
-      final Uri packageUri =_packageMap[packageName];
-      _scanDirectory(packageUri, invalidatedFiles);
     }
+    printTrace('Scanned through $scanned files in ${stopwatch.elapsedMilliseconds}ms');
     return invalidatedFiles;
   }
-
-  void _scanDirectory(Uri path, List<String> invalidatedFiles) {
-    final Directory directory = fs.directory(path);
-    if (!directory.existsSync()) {
-      return;
-    }
-    for (FileSystemEntity entity in directory.listSync(recursive: true)) {
-      if (entity.path.endsWith('.dart')) {
-        final int oldUpdatedAt = _updateTime[entity.path];
-        final int updatedAt = fs.statSync(entity.path).modified.millisecondsSinceEpoch;
-        if (oldUpdatedAt == null || updatedAt > oldUpdatedAt) {
-          // On windows convert to file uri in expected format.
-          if (platform.isWindows) {
-            final Uri uri = Uri.file(entity.path, windows: platform.isWindows);
-            invalidatedFiles.add(uri.toString());
-          } else {
-            invalidatedFiles.add(entity.path);
-          }
-        }
-        _updateTime[entity.path] = updatedAt;
-      }
-    }
-  }
-}
+}
\ No newline at end of file

packages/flutter_tools/lib/src/test/flutter_platform.dart

@@ -311,7 +311,7 @@ class _Compiler {
           suppressOutput = false;
           final CompilerOutput compilerOutput = await compiler.recompile(
             request.path,
-            <String>[request.path],
+            <Uri>[Uri.parse(request.path)],
             outputPath: outputDill.path,
           );
           final String outputPath = compilerOutput?.outputFilename;

packages/flutter_tools/lib/src/tester/flutter_tester.dart

@@ -96,7 +96,6 @@ class FlutterTesterDevice extends Device {
     @required DebuggingOptions debuggingOptions,
     Map<String, dynamic> platformArgs,
     bool prebuiltApplication = false,
-    bool applicationNeedsRebuild = false,
     bool usesTerminalUi = true,
     bool ipv6 = false,
   }) async {

packages/flutter_tools/lib/src/web/web_device.dart

@@ -100,7 +100,6 @@ class WebDevice extends Device {
     DebuggingOptions debuggingOptions,
     Map<String, Object> platformArgs,
     bool prebuiltApplication = false,
-    bool applicationNeedsRebuild = false,
     bool usesTerminalUi = true,
     bool ipv6 = false,
   }) async {

packages/flutter_tools/lib/src/windows/windows_device.dart

@@ -57,7 +57,6 @@ class WindowsDevice extends Device {
     DebuggingOptions debuggingOptions,
     Map<String, dynamic> platformArgs,
     bool prebuiltApplication = false,
-    bool applicationNeedsRebuild = false,
     bool usesTerminalUi = true,
     bool ipv6 = false,
   }) {

packages/flutter_tools/test/compile_test.dart

@@ -517,7 +517,7 @@ Future<void> _recompile(
   });
   final CompilerOutput output = await generator.recompile(
     null /* mainPath */,
-    <String>['/path/to/main.dart'],
+    <Uri>[Uri.parse('/path/to/main.dart')],
     outputPath: '/build/',
   );
   expect(output.outputFilename, equals('/path/to/main.dart.dill'));

packages/flutter_tools/test/devfs_test.dart

@@ -123,7 +123,7 @@ void main() {
         generator: residentCompiler,
         pathToReload: 'lib/foo.txt.dill',
         trackWidgetCreation: false,
-        invalidatedFiles: <String>[],
+        invalidatedFiles: <Uri>[],
       );
       vmService.expectMessages(<String>[
         'writeFile test lib/foo.txt.dill',

packages/flutter_tools/test/hot_test.dart

@@ -116,6 +116,8 @@ void main() {
         UpdateFSReport(success: true, syncedBytes: 1000, invalidatedSourcesCount: 1)));
     when(mockDevFs.assetPathsToEvict).thenReturn(<String>{});
     when(mockDevFs.baseUri).thenReturn(Uri.file('test'));
+    when(mockDevFs.sources).thenReturn(<Uri>[Uri.file('test')]);
+    when(mockDevFs.lastCompiled).thenReturn(DateTime.now());
 
     setUp(() {
       mockArtifacts = MockLocalEngineArtifacts();

packages/flutter_tools/test/project_file_invalidator_test.dart

@@ -4,231 +4,30 @@
 
 import 'package:file/memory.dart';
 import 'package:flutter_tools/src/base/file_system.dart';
-import 'package:flutter_tools/src/base/logger.dart';
-import 'package:flutter_tools/src/base/platform.dart';
-import 'package:flutter_tools/src/project.dart';
 import 'package:flutter_tools/src/run_hot.dart';
-import 'package:mockito/mockito.dart';
 
 import 'src/common.dart';
 import 'src/context.dart';
 
 void main() {
-  final Platform windowsPlatform = MockPlatform();
-  final Platform notWindowsPlatform = MockPlatform();
-  final BufferLogger bufferLogger = BufferLogger();
-  when(windowsPlatform.isWindows).thenReturn(true);
-  when(notWindowsPlatform.isWindows).thenReturn(false);
-
-  group('ProjectFileInvalidator linux/mac', () {
+  group('ProjectFileInvalidator', () {
     final MemoryFileSystem memoryFileSystem = MemoryFileSystem();
-    final File packagesFile = memoryFileSystem.file('.packages')
-      ..createSync()
-      ..writeAsStringSync(r'''
-foo:file:///foo/lib/
-bar:file:///.pub-cache/bar/lib/
-baz:file:///baz/lib/
-test_package:file:///lib/
-''');
-    final File pubspecFile = memoryFileSystem.file('pubspec.yaml')
-      ..createSync()
-      ..writeAsStringSync(r'''
-name: test_package
-
-dependencies:
-  foo: any
-  bar:
-
-dev_dependencies:
-  baz: any
-''');
-    final File mainFile = memoryFileSystem.file('lib/main.dart')
-      ..createSync(recursive: true)
-      ..writeAsStringSync(r'''
-void main() {}
-''');
-    final File fooFile = memoryFileSystem.file('foo/lib/foo.dart')
-      ..createSync(recursive: true)
-      ..writeAsStringSync('');
-    memoryFileSystem.file('bar/lib/bar.dart')
-      ..createSync(recursive: true)
-      ..writeAsStringSync('');
-    final File bazFile = memoryFileSystem.file('baz/lib/baz.dart')
-      ..createSync(recursive: true)
-      ..writeAsStringSync('');
-
-    testUsingContext('No .packages, no pubspec', () async {
-      // Instead of setting up multiple filesystems, passing a .packages file which does not exist.
-      final ProjectFileInvalidator invalidator = ProjectFileInvalidator('.packages-wrong', null);
-      invalidator.findInvalidated();
-      expect(invalidator.packageMap, isEmpty);
-      expect(invalidator.updateTime, isEmpty);
-    }, overrides: <Type, Generator>{
-      FileSystem: () => memoryFileSystem,
-      Platform: () => notWindowsPlatform,
-    });
-
-    testUsingContext('.packages only', () async {
-      final ProjectFileInvalidator invalidator = ProjectFileInvalidator(packagesFile.path, null);
-      invalidator.findInvalidated();
-      expect(invalidator.packageMap, <String, Uri>{
-        'foo': Uri.parse('file:///foo/lib/'),
-        // Excluded because it is in pub cache.
-        // 'bar': Uri.parse('file:///.pub-cache/bar/lib/'),
-        'baz': Uri.parse('file:///baz/lib/'),
-        'test_package': Uri.parse('file:///lib/'),
-      });
-      expect(invalidator.updateTime, <String, int>{
-        '/baz/lib/baz.dart': bazFile.statSync().modified.millisecondsSinceEpoch,
-        '/lib/main.dart': mainFile.statSync().modified.millisecondsSinceEpoch,
-        '/foo/lib/foo.dart': fooFile.statSync().modified.millisecondsSinceEpoch,
-      });
+    testUsingContext('Empty project', () async {
+      expect(
+        ProjectFileInvalidator.findInvalidated(lastCompiled: DateTime.now(), urisToMonitor: <Uri>[]),
+        isEmpty);
     }, overrides: <Type, Generator>{
       FileSystem: () => memoryFileSystem,
-      Platform: () => notWindowsPlatform,
     });
 
-    testUsingContext('.packages and pubspec', () async {
-      final FlutterProject flutterProject = await FlutterProject.fromDirectory(pubspecFile.parent);
-      final ProjectFileInvalidator invalidator = ProjectFileInvalidator(packagesFile.path, flutterProject);
-      invalidator.findInvalidated();
-      expect(invalidator.packageMap, <String, Uri>{
-        'foo': Uri.parse('file:///foo/lib/'),
-        // Excluded because it is in pub cache.
-        // 'bar': Uri.parse('file:///.pub-cache/bar/lib/'),
-        // Excluded because it is a dev dependency/
-        // 'baz': Uri.parse('file:///baz/lib/'),
-        'test_package': Uri.parse('file:///lib/'),
-      });
-      expect(invalidator.updateTime, <String, int>{
-        '/foo/lib/foo.dart': fooFile.statSync().modified.millisecondsSinceEpoch,
-        '/lib/main.dart': mainFile.statSync().modified.millisecondsSinceEpoch,
-      });
-      expect(invalidator.findInvalidated(), isEmpty);
-
-      // Invalidate main.dart.
-      mainFile.writeAsStringSync('void main() { }');
-      expect(invalidator.findInvalidated(), <String>['/lib/main.dart']);
-    }, overrides: <Type, Generator>{
-      FileSystem: () => memoryFileSystem,
-      Platform: () => notWindowsPlatform,
-    });
-
-    testUsingContext('update to .packages triggers warning', () async {
-      final FlutterProject flutterProject = await FlutterProject.fromDirectory(pubspecFile.parent);
-      final ProjectFileInvalidator invalidator = ProjectFileInvalidator(packagesFile.path, flutterProject);
-      invalidator.findInvalidated();
-      packagesFile.writeAsStringSync(r'''
-foo:file:///foo/lib/
-bar:file:///.pub-cache/bar/lib/
-baz:file:///baz/lib/
-new_dep:file:///new_dep/lib/
-test_package:file:///lib/
-''');
-      invalidator.findInvalidated();
-      expect(bufferLogger.errorText, 'Warning: updated dependencies detected. The Flutter application will require a restart to safely use new packages.\n');
+    testUsingContext('Non-existent files are ignored', () async {
+      expect(
+        ProjectFileInvalidator.findInvalidated(
+            lastCompiled: DateTime.now(),
+            urisToMonitor: <Uri>[Uri.parse('/not-there-anymore')]),
+        isEmpty);
     }, overrides: <Type, Generator>{
       FileSystem: () => memoryFileSystem,
-      Platform: () => notWindowsPlatform,
-      Logger: () => bufferLogger,
-    });
-  });
-
-  group('ProjectFileInvalidator windows', () {
-    final MemoryFileSystem memoryFileSystem = MemoryFileSystem(style: FileSystemStyle.windows);
-    // On windows .packages still contains file Uris, albeit ones with the Drive prefix.
-    final File packagesFile = memoryFileSystem.file(r'C:\.packages')
-      ..createSync()
-      ..writeAsStringSync(r'''
-foo:file:///C:/foo/lib/
-bar:file:///C:/Pub/Cache/bar/lib/
-baz:file:///C:/baz/lib/
-test_package:file:///C:/lib/
-''');
-    memoryFileSystem.file(r'C:\pubspec.yaml')
-      ..createSync()
-      ..writeAsStringSync(r'''
-name: test_package
-
-dependencies:
-  foo: any
-  bar:
-
-dev_dependencies:
-  baz: any
-''');
-    final File mainFile = memoryFileSystem.file(r'C:\lib\main.dart')
-      ..createSync(recursive: true)
-      ..writeAsStringSync(r'''
-void main() {}
-''');
-    final File fooFile = memoryFileSystem.file(r'C:\foo\lib\foo.dart')
-      ..createSync(recursive: true)
-      ..writeAsStringSync('');
-    memoryFileSystem.file(r'C:\bar\lib\bar.dart')
-      ..createSync(recursive: true)
-      ..writeAsStringSync('');
-    final File bazFile = memoryFileSystem.file(r'C:\baz\lib\baz.dart')
-      ..createSync(recursive: true)
-      ..writeAsStringSync('');
-
-    testUsingContext('No .packages, no pubspec', () async {
-      // Instead of setting up multiple filesystems, passing a .packages file which does not exist.
-      final ProjectFileInvalidator invalidator = ProjectFileInvalidator('.packages-wrong', null);
-      invalidator.findInvalidated();
-      expect(invalidator.packageMap, isEmpty);
-      expect(invalidator.updateTime, isEmpty);
-    }, overrides: <Type, Generator>{
-      FileSystem: () => memoryFileSystem,
-      Platform: () => windowsPlatform,
-    });
-
-    testUsingContext('.packages only', () async {
-      final ProjectFileInvalidator invalidator = ProjectFileInvalidator(packagesFile.path, null);
-      invalidator.findInvalidated();
-      expect(invalidator.packageMap, <String, Uri>{
-        'foo': Uri.file(r'C:\foo\lib\', windows: true),
-        // Excluded because it is in pub cache.
-        // 'bar': Uri.parse('file:///Pub/Cache/bar/lib/'),
-        'baz': Uri.file(r'C:\baz\lib\', windows: true),
-        'test_package': Uri.file(r'C:\lib\', windows: true),
-      });
-      expect(invalidator.updateTime, <String, int>{
-        r'C:\baz\lib\baz.dart': bazFile.statSync().modified.millisecondsSinceEpoch,
-        r'C:\lib\main.dart': mainFile.statSync().modified.millisecondsSinceEpoch,
-        r'C:\foo\lib\foo.dart': fooFile.statSync().modified.millisecondsSinceEpoch,
-      });
-    }, overrides: <Type, Generator>{
-      FileSystem: () => memoryFileSystem,
-      Platform: () => windowsPlatform,
-    });
-
-    testUsingContext('.packages and pubspec', () async {
-      final FlutterProject flutterProject = await FlutterProject.fromDirectory(fs.directory(r'C:\'));
-      final ProjectFileInvalidator invalidator = ProjectFileInvalidator(packagesFile.path, flutterProject);
-      invalidator.findInvalidated();
-      expect(invalidator.packageMap, <String, Uri>{
-        'foo': Uri.file(r'C:\foo\lib\', windows: true),
-        // Excluded because it is in pub cache.
-        // 'bar': Uri.parse('file:///C:/Pub/Cache/bar/lib/'),
-        // Excluded because it is a dev dependency/
-        // 'baz': Uri.parse('file:///baz/lib/'),
-        'test_package': Uri.file(r'C:\lib\', windows: true),
-      });
-      expect(invalidator.updateTime, <String, int>{
-        r'C:\lib\main.dart': mainFile.statSync().modified.millisecondsSinceEpoch,
-        r'C:\foo\lib\foo.dart': fooFile.statSync().modified.millisecondsSinceEpoch,
-      });
-      expect(invalidator.findInvalidated(), isEmpty);
-
-      // Invalidate main.dart.
-      mainFile.writeAsStringSync('void main() { }');
-      expect(invalidator.findInvalidated(), <String>['file:///C:/lib/main.dart']);
-    }, overrides: <Type, Generator>{
-      FileSystem: () => memoryFileSystem,
-      Platform: () => windowsPlatform,
     });
   });
 }
-
-class MockPlatform extends Mock implements Platform {}

packages/flutter_tools/test/src/mocks.dart

@@ -487,7 +487,7 @@ class MockResidentCompiler extends BasicMock implements ResidentCompiler {
     return null;
   }
   @override
-  Future<CompilerOutput> recompile(String mainPath, List<String> invalidatedFiles, { String outputPath, String packagesFilePath }) async {
+  Future<CompilerOutput> recompile(String mainPath, List<Uri> invalidatedFiles, { String outputPath, String packagesFilePath }) async {
     fs.file(outputPath).createSync(recursive: true);
     fs.file(outputPath).writeAsStringSync('compiled_kernel_output');
     return CompilerOutput(outputPath, 0, <Uri>[]);