[flutter_tools] use fixed entry for dill uploads (#67837)

For historical reasons, the flutter tool uploads dill files to paths based on the entrypoint URI. This isn't actually necessary, and the tool can use specific files : main.dart.incremental.dill for incremental dills, and main.dart.dill/main.dart.swap.dill for full dills. This allows hot restarting applications with an entrypoint outside of lib/ and simplifies the devFS code.

Fixes #63243

packages/flutter_tools/lib/src/devfs.dart

@@ -548,16 +548,13 @@ class DevFS {
     if (!bundleFirstUpload) {
       final String compiledBinary = compilerOutput?.outputFilename;
       if (compiledBinary != null && compiledBinary.isNotEmpty) {
-        final Uri entryUri = _fileSystem.path.toUri(projectRootPath != null
-          ? _fileSystem.path.relative(pathToReload, from: projectRootPath)
-          : pathToReload,
-        );
+        final Uri entryUri = _fileSystem.path.toUri(pathToReload);
         final DevFSFileContent content = DevFSFileContent(_fileSystem.file(compiledBinary));
         syncedBytes += content.size;
         dirtyEntries[entryUri] = content;
       }
     }
-    _logger.printTrace('Updating files');
+    _logger.printTrace('Updating files.');
     if (dirtyEntries.isNotEmpty) {
       await (devFSWriter ?? _httpWriter).write(dirtyEntries, _baseUri, _httpWriter);
     }

packages/flutter_tools/lib/src/resident_runner.dart

@@ -782,9 +782,9 @@ abstract class ResidentRunner {
     @required bool swap,
   }) {
     if (!fullRestart) {
-      return '$mainPath.incremental.dill';
+      return 'main.dart.incremental.dill';
     }
-    return '$mainPath${swap ? '.swap' : ''}.dill';
+    return 'main.dart${swap ? '.swap' : ''}.dill';
   }
 
   bool get debuggingEnabled => debuggingOptions.debuggingEnabled;

packages/flutter_tools/lib/src/run_hot.dart

@@ -451,12 +451,10 @@ class HotRunner extends ResidentRunner {
     ]);
   }
 
-  Future<void> _launchFromDevFS(String mainScript) async {
-    final String entryUri = globals.fs.path.relative(mainScript, from: projectRootPath);
+  Future<void> _launchFromDevFS() async {
     final List<Future<void>> futures = <Future<void>>[];
     for (final FlutterDevice device in flutterDevices) {
-      final Uri deviceEntryUri = device.devFS.baseUri.resolveUri(
-        globals.fs.path.toUri(entryUri));
+      final Uri deviceEntryUri = device.devFS.baseUri.resolve(_swap ? 'main.dart.swap.dill' : 'main.dart.dill');
       final Uri deviceAssetsDirectoryUri = device.devFS.baseUri.resolveUri(
         globals.fs.path.toUri(getAssetBuildDirectory()));
       futures.add(_launchInView(device,
@@ -555,7 +553,7 @@ class HotRunner extends ResidentRunner {
     }
     await Future.wait(operations);
 
-    await _launchFromDevFS('$mainPath${_swap ? '.swap' : ''}.dill');
+    await _launchFromDevFS();
     restartTimer.stop();
     globals.printTrace('Hot restart performed in ${getElapsedAsMilliseconds(restartTimer.elapsed)}.');
     _addBenchmarkData('hotRestartMillisecondsToFrame',
@@ -793,7 +791,7 @@ class HotRunner extends ResidentRunner {
     bool pause = false,
   }) async {
     final String deviceEntryUri = device.devFS.baseUri
-      .resolveUri(globals.fs.path.toUri(entryPath)).toString();
+      .resolve(entryPath).toString();
     final vm_service.VM vm = await device.vmService.getVM();
     return <Future<vm_service.ReloadReport>>[
       for (final vm_service.IsolateRef isolateRef in vm.isolates)
@@ -849,10 +847,7 @@ class HotRunner extends ResidentRunner {
     final Stopwatch vmReloadTimer = Stopwatch()..start();
     Map<String, dynamic> firstReloadDetails;
     try {
-      final String entryPath = globals.fs.path.relative(
-        getReloadPath(fullRestart: false, swap: _swap),
-        from: projectRootPath,
-      );
+      const String entryPath = 'main.dart.incremental.dill';
       final List<Future<DeviceReloadReport>> allReportsFutures = <Future<DeviceReloadReport>>[];
       for (final FlutterDevice device in flutterDevices) {
         if (_shouldResetAssetDirectory) {

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

@@ -16,6 +16,7 @@ import '../base/logger.dart';
 import '../build_info.dart';
 import '../bundle.dart';
 import '../convert.dart';
+import '../devfs.dart';
 import '../device.dart';
 import '../project.dart';
 import '../protocol_discovery.dart';
@@ -44,7 +45,6 @@ class FlutterTesterApp extends ApplicationPackage {
 /// Normally this is only used as the runner for `flutter test`, but it can
 /// also be used as a regular device when `--show-test-device` is provided
 /// to the flutter command.
-// TODO(scheglov): This device does not currently work with full restarts.
 class FlutterTesterDevice extends Device {
   FlutterTesterDevice(String deviceId, {
     @required ProcessManager processManager,
@@ -245,6 +245,16 @@ class FlutterTesterDevice extends Device {
   @override
   bool isSupportedForProject(FlutterProject flutterProject) => true;
 
+  @override
+  DevFSWriter createDevFSWriter(
+    covariant ApplicationPackage app,
+    String userIdentifier,
+  ) {
+    return LocalDevFSWriter(
+      fileSystem: _fileSystem,
+    );
+  }
+
   @override
   Future<void> dispose() async {
     _logReader?.dispose();

packages/flutter_tools/test/general.shard/hot_test.dart

@@ -283,7 +283,7 @@ void main() {
           method: kRunInViewMethod,
           args: <String, Object>{
             'viewId': fakeFlutterView.id,
-            'mainScript': 'lib/main.dart.dill',
+            'mainScript': 'main.dart.dill',
             'assetDirectory': 'build/flutter_assets',
           }
         ),
@@ -291,7 +291,7 @@ void main() {
           method: kRunInViewMethod,
           args: <String, Object>{
             'viewId': fakeFlutterView.id,
-            'mainScript': 'lib/main.dart.dill',
+            'mainScript': 'main.dart.dill',
             'assetDirectory': 'build/flutter_assets',
           }
         ),
@@ -383,7 +383,7 @@ void main() {
           method: kRunInViewMethod,
           args: <String, Object>{
             'viewId': fakeFlutterView.id,
-            'mainScript': 'lib/main.dart.dill',
+            'mainScript': 'main.dart.dill',
             'assetDirectory': 'build/flutter_assets',
           }
         ),

packages/flutter_tools/test/general.shard/resident_runner_test.dart

@@ -71,7 +71,7 @@ final vm_service.Isolate fakePausedIsolate = vm_service.Isolate(
       id: 'test-breakpoint',
       location: vm_service.SourceLocation(
         tokenPos: 0,
-        script: vm_service.ScriptRef(id: 'test-script', uri: 'lib/foo.dart'),
+        script: vm_service.ScriptRef(id: 'test-script', uri: 'foo.dart'),
       ),
       resolved: true,
     ),
@@ -411,7 +411,7 @@ void main() {
         method: kRunInViewMethod,
         args: <String, Object>{
           'viewId': fakeFlutterView.id,
-          'mainScript': 'lib/main.dart.dill',
+          'mainScript': 'main.dart.dill',
           'assetDirectory': 'build/flutter_assets',
         }
       ),
@@ -606,7 +606,7 @@ void main() {
         args: <String, Object>{
           'isolateId': '1',
           'pause': false,
-          'rootLibUri': 'lib/main.dart.incremental.dill'
+          'rootLibUri': 'main.dart.incremental.dill'
         },
         jsonResponse: <String, Object>{
           'type': 'ReloadReport',
@@ -699,7 +699,7 @@ void main() {
         args: <String, Object>{
           'isolateId': '1',
           'pause': false,
-          'rootLibUri': 'lib/main.dart.incremental.dill'
+          'rootLibUri': 'main.dart.incremental.dill'
         },
         jsonResponse: <String, Object>{
           'type': 'ReloadReport',
@@ -795,7 +795,7 @@ void main() {
         args: <String, Object>{
           'isolateId': '1',
           'pause': false,
-          'rootLibUri': 'lib/main.dart.incremental.dill'
+          'rootLibUri': 'main.dart.incremental.dill'
         },
         jsonResponse: <String, Object>{
           'type': 'ReloadReport',
@@ -875,7 +875,7 @@ void main() {
         args: <String, Object>{
           'isolateId': '1',
           'pause': false,
-          'rootLibUri': 'lib/main.dart.incremental.dill',
+          'rootLibUri': 'main.dart.incremental.dill',
         },
         jsonResponse: <String, Object>{
           'type': 'ReloadReport',
@@ -992,7 +992,7 @@ void main() {
         method: kRunInViewMethod,
         args: <String, Object>{
           'viewId': fakeFlutterView.id,
-          'mainScript': 'lib/main.dart.dill',
+          'mainScript': 'main.dart.dill',
           'assetDirectory': 'build/flutter_assets',
         },
       ),
@@ -1074,7 +1074,7 @@ void main() {
         method: kRunInViewMethod,
         args: <String, Object>{
           'viewId': fakeFlutterView.id,
-          'mainScript': 'lib/main.dart.dill',
+          'mainScript': 'main.dart.dill',
           'assetDirectory': 'build/flutter_assets',
         },
       ),
@@ -1136,7 +1136,7 @@ void main() {
         method: kRunInViewMethod,
         args: <String, Object>{
           'viewId': fakeFlutterView.id,
-          'mainScript': 'lib/main.dart.dill',
+          'mainScript': 'main.dart.dill',
           'assetDirectory': 'build/flutter_assets',
         },
       ),
@@ -1170,7 +1170,7 @@ void main() {
         method: kRunInViewMethod,
         args: <String, Object>{
           'viewId': fakeFlutterView.id,
-          'mainScript': 'lib/main.dart.swap.dill',
+          'mainScript': 'main.dart.swap.dill',
           'assetDirectory': 'build/flutter_assets',
         },
       ),
@@ -1204,7 +1204,7 @@ void main() {
         method: kRunInViewMethod,
         args: <String, Object>{
           'viewId': fakeFlutterView.id,
-          'mainScript': 'lib/main.dart.dill',
+          'mainScript': 'main.dart.dill',
           'assetDirectory': 'build/flutter_assets',
         },
       ),