copy chrome preferences to seeded data dir (#44032)

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

@@ -4,6 +4,7 @@
 
 import 'dart:async';
 
+import 'package:meta/meta.dart';
 import 'package:webkit_inspection_protocol/webkit_inspection_protocol.dart';
 
 import '../base/common.dart';
@@ -65,13 +66,18 @@ String findChromeExecutable() {
   return null;
 }
 
+@visibleForTesting
+void resetChromeForTesting() {
+  ChromeLauncher._currentCompleter = Completer<Chrome>();
+}
+
 /// Responsible for launching chrome with devtools configured.
 class ChromeLauncher {
   const ChromeLauncher();
 
   static bool get hasChromeInstance => _currentCompleter.isCompleted;
 
-  static final Completer<Chrome> _currentCompleter = Completer<Chrome>();
+  static Completer<Chrome> _currentCompleter = Completer<Chrome>();
 
   /// Whether we can locate the chrome executable.
   bool canFindChrome() {
@@ -89,15 +95,31 @@ class ChromeLauncher {
   /// a `headfull` browser.
   ///
   /// `skipCheck` does not attempt to make a devtools connection before returning.
-  Future<Chrome> launch(String url, { bool headless = false, bool skipCheck = false }) async {
+  Future<Chrome> launch(String url, { bool headless = false, bool skipCheck = false, Directory dataDir }) async {
+    // This is a JSON file which contains configuration from the
+    // browser session, such as window position. It is located
+    // under the Chrome data-dir folder.
+    final String preferencesPath = fs.path.join('Default', 'preferences');
+
     final String chromeExecutable = findChromeExecutable();
-    final Directory dataDir = fs.systemTempDirectory.createTempSync('flutter_tool.');
+    final Directory activeDataDir = fs.systemTempDirectory.createTempSync('flutter_tool.');
+    // Seed data dir with previous state.
+
+    final File savedPreferencesFile = fs.file(fs.path.join(dataDir?.path ?? '', preferencesPath));
+    final File destinationFile = fs.file(fs.path.join(activeDataDir.path, preferencesPath));
+    if (dataDir != null) {
+      if (savedPreferencesFile.existsSync()) {
+        destinationFile.parent.createSync(recursive: true);
+        savedPreferencesFile.copySync(destinationFile.path);
+      }
+    }
+
     final int port = await os.findFreePort();
     final List<String> args = <String>[
       chromeExecutable,
       // Using a tmp directory ensures that a new instance of chrome launches
       // allowing for the remote debug port to be enabled.
-      '--user-data-dir=${dataDir.path}',
+      '--user-data-dir=${activeDataDir.path}',
       '--remote-debugging-port=$port',
       // When the DevTools has focus we don't want to slow down the application.
       '--disable-background-timer-throttling',
@@ -117,6 +139,21 @@ class ChromeLauncher {
 
     final Process process = await processManager.start(args);
 
+    // When the process exits, copy the user settings back to the provided
+    // data-dir.
+    if (dataDir != null) {
+      unawaited(process.exitCode.whenComplete(() {
+        if (destinationFile.existsSync()) {
+          savedPreferencesFile.parent.createSync(recursive: true);
+          // If the file contains a crash string, remove it to hide
+          // the popup on next run.
+          final String contents = destinationFile.readAsStringSync();
+          savedPreferencesFile.writeAsStringSync(contents
+            .replaceFirst('"exit_type":"Crashed"', '"exit_type":"Normal"'));
+        }
+      }));
+    }
+
     // Wait until the DevTools are listening before trying to connect.
     await process.stderr
         .transform(utf8.decoder)

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

@@ -132,7 +132,10 @@ class ChromeDevice extends Device {
     // for the web initialization and server logic.
     final String url = platformArgs['uri'];
     if (debuggingOptions.browserLaunch) {
-      _chrome = await chromeLauncher.launch(url);
+      _chrome = await chromeLauncher.launch(url,
+        dataDir: fs.currentDirectory
+          .childDirectory('.dart_tool')
+          .childDirectory('chrome-device'));
     } else {
       printStatus('Waiting for connection from Dart debug extension at $url', emphasis: true);
       logger.sendNotification(url, progressId: 'debugExtension');

packages/flutter_tools/test/general.shard/web/chrome_test.dart

@@ -19,33 +19,43 @@ import '../../src/testbed.dart';
 
 void main() {
   Testbed testbed;
+  Completer<int> exitCompleter;
 
   setUp(() {
     final MockPlatform platform = MockPlatform();
+    exitCompleter = Completer<int>.sync();
     when(platform.isWindows).thenReturn(false);
-    final MockFileSystem mockFileSystem = MockFileSystem();
     testbed = Testbed(overrides: <Type, Generator>{
       ProcessManager: () => MockProcessManager(),
       Platform: () => platform,
       OperatingSystemUtils: () => MockOperatingSystemUtils(),
-      FileSystem: () => mockFileSystem,
+    }, setup: () {
+      when(os.findFreePort()).thenAnswer((Invocation invocation) async {
+        return 1234;
+      });
+      when(platform.environment).thenReturn(<String, String>{
+        kChromeEnvironment: 'example_chrome',
+      });
+      when(processManager.start(any))
+        .thenAnswer((Invocation invocation) async {
+        return FakeProcess(
+          exitCode: exitCompleter.future,
+          stdout: const Stream<List<int>>.empty(),
+          stderr: Stream<List<int>>.fromIterable(<List<int>>[
+            utf8.encode('\n\nDevTools listening\n\n'),
+          ]),
+        );
+      });
     });
   });
 
+  tearDown(() {
+    resetChromeForTesting();
+  });
+
   test('can launch chrome and connect to the devtools', () => testbed.run(() async {
-    when(os.findFreePort()).thenAnswer((Invocation invocation) async {
-      return 1234;
-    });
-    when(platform.environment).thenReturn(<String, String>{
-      kChromeEnvironment: 'example_chrome',
-    });
-    final Directory mockDirectory = MockDirectory();
-    when(fs.systemTempDirectory).thenReturn(mockDirectory);
-    when(mockDirectory.createTempSync(any)).thenReturn(mockDirectory);
-    when(mockDirectory.path).thenReturn('example');
-    when(processManager.start(<String>[
+    const List<String> expected = <String>[
       'example_chrome',
-      '--user-data-dir=example',
       '--remote-debugging-port=1234',
       '--disable-background-timer-throttling',
       '--disable-extensions',
@@ -56,22 +66,45 @@ void main() {
       '--disable-default-apps',
       '--disable-translate',
       'example_url',
-    ])).thenAnswer((Invocation invocation) async {
-      return FakeProcess(
-        exitCode: Completer<int>().future,
-        stdout: const Stream<List<int>>.empty(),
-        stderr: Stream<List<int>>.fromIterable(<List<int>>[
-          utf8.encode('\n\nDevTools listening\n\n'),
-        ]),
-      );
-    });
+    ];
 
     await chromeLauncher.launch('example_url', skipCheck: true);
+    final VerificationResult result = verify(processManager.start(captureAny));
+
+    expect(result.captured.single, containsAll(expected));
+  }));
+
+  test('can seed chrome temp directory with existing preferences', () => testbed.run(() async {
+    final Directory dataDir = fs.directory('chrome-stuff');
+    final File preferencesFile = dataDir
+      .childDirectory('Default')
+      .childFile('preferences');
+    preferencesFile
+      ..createSync(recursive: true)
+      ..writeAsStringSync('example');
+
+    await chromeLauncher.launch('example_url', skipCheck: true, dataDir: dataDir);
+    final VerificationResult result = verify(processManager.start(captureAny));
+    final String arg = result.captured.single
+      .firstWhere((String arg) => arg.startsWith('--user-data-dir='));
+    final Directory tempDirectory = fs.directory(arg.split('=')[1]);
+    final File tempFile = tempDirectory
+      .childDirectory('Default')
+      .childFile('preferences');
+
+    expect(tempFile.existsSync(), true);
+    expect(tempFile.readAsStringSync(), 'example');
+
+    // write crash to file:
+    tempFile.writeAsStringSync('"exit_type":"Crashed"');
+    exitCompleter.complete(0);
+
+    // writes non-crash back to dart_tool
+    expect(preferencesFile.readAsStringSync(), '"exit_type":"Normal"');
   }));
 }
 
 class MockProcessManager extends Mock implements ProcessManager {}
 class MockPlatform extends Mock implements Platform {}
 class MockOperatingSystemUtils extends Mock implements OperatingSystemUtils {}
-class MockFileSystem extends Mock implements FileSystem {}
-class MockDirectory extends Mock implements Directory {}
+