[driver] refactor API to finder objects (#3365)

dev/benchmarks/complex_layout/test_driver/scroll_perf_test.dart

@@ -22,7 +22,7 @@ void main() {
     test('measure', () async {
       Timeline timeline = await driver.traceAction(() async {
         // Find the scrollable stock list
-        ObjectRef stockList = await driver.findByValueKey('main-scroll');
+        SerializableFinder stockList = find.byValueKey('main-scroll');
         expect(stockList, isNotNull);
 
         // Scroll down

examples/material_gallery/test_driver/scroll_perf_test.dart

@@ -22,12 +22,12 @@ void main() {
     test('measure', () async {
       Timeline timeline = await driver.traceAction(() async {
         // Find the scrollable stock list
-        ObjectRef stockList = await driver.findByValueKey('Gallery List');
+        SerializableFinder stockList = find.byValueKey('Gallery List');
         expect(stockList, isNotNull);
 
-        await driver.tap(await driver.findByText('Demos'));
-        await driver.tap(await driver.findByText('Components'));
-        await driver.tap(await driver.findByText('Style'));
+        await driver.tap(find.text('Demos'));
+        await driver.tap(find.text('Components'));
+        await driver.tap(find.text('Style'));
 
         // TODO(eseidel): These are very artifical scrolls, we should use better
         // https://github.com/flutter/flutter/issues/3316

examples/stocks/test_driver/scroll_perf_test.dart

@@ -23,7 +23,7 @@ void main() {
     test('measure', () async {
       Timeline timeline = await driver.traceAction(() async {
         // Find the scrollable stock list
-        ObjectRef stockList = await driver.findByValueKey('stock-list');
+        SerializableFinder stockList = find.byValueKey('stock-list');
         expect(stockList, isNotNull);
 
         // Scroll down

packages/flutter_driver/lib/flutter_driver.dart

@@ -12,6 +12,9 @@
 library flutter_driver;
 
 export 'src/driver.dart' show
+  find,
+  CommonFinders,
+  EvaluatorFunction,
   FlutterDriver;
 
 export 'src/error.dart' show
@@ -21,7 +24,7 @@ export 'src/error.dart' show
   flutterDriverLog;
 
 export 'src/find.dart' show
-  ObjectRef,
+  SerializableFinder,
   GetTextResult;
 
 export 'src/health.dart' show
@@ -31,7 +34,6 @@ export 'src/health.dart' show
 export 'src/message.dart' show
   Message,
   Command,
-  ObjectRef,
   CommandWithTarget,
   Result;
 

packages/flutter_driver/lib/src/driver.dart

@@ -20,6 +20,14 @@ import 'timeline.dart';
 
 final Logger _log = new Logger('FlutterDriver');
 
+/// A convenient accessor to frequently used finders.
+///
+/// Examples:
+///
+///     driver.tap(find.byText('Save'));
+///     driver.scroll(find.byValueKey(42));
+const CommonFinders find = const CommonFinders._();
+
 /// Computes a value.
 ///
 /// If computation is asynchronous, the function may return a [Future].
@@ -162,14 +170,15 @@ class FlutterDriver {
   Future<Map<String, dynamic>> _sendCommand(Command command) async {
     Map<String, String> parameters = <String, String>{'command': command.kind}
       ..addAll(command.serialize());
-    return _appIsolate.invokeExtension(_kFlutterExtensionMethod, parameters)
-      .then((Map<String, dynamic> result) => result, onError: (dynamic error, dynamic stackTrace) {
-        throw new DriverError(
-          'Failed to fulfill ${command.runtimeType} due to remote error',
-          error,
-          stackTrace
-        );
-      });
+    try {
+      return await _appIsolate.invokeExtension(_kFlutterExtensionMethod, parameters);
+    } catch (error, stackTrace) {
+      throw new DriverError(
+        'Failed to fulfill ${command.runtimeType} due to remote error',
+        error,
+        stackTrace
+      );
+    }
   }
 
   /// Checks the status of the Flutter Driver extension.
@@ -177,23 +186,14 @@ class FlutterDriver {
     return Health.fromJson(await _sendCommand(new GetHealth()));
   }
 
-  /// Finds the UI element with the given [key].
-  Future<ObjectRef> findByValueKey(dynamic key) async {
-    return ObjectRef.fromJson(await _sendCommand(new Find(new ByValueKey(key))));
-  }
-
-  /// Finds the UI element for the tooltip with the given [message].
-  Future<ObjectRef> findByTooltipMessage(String message) async {
-    return ObjectRef.fromJson(await _sendCommand(new Find(new ByTooltipMessage(message))));
-  }
-
-  /// Finds the text element with the given [text].
-  Future<ObjectRef> findByText(String text) async {
-    return ObjectRef.fromJson(await _sendCommand(new Find(new ByText(text))));
+  /// Taps at the center of the widget located by [finder].
+  Future<Null> tap(SerializableFinder finder) async {
+    return await _sendCommand(new Tap(finder)).then((Map<String, dynamic> _) => null);
   }
 
-  Future<Null> tap(ObjectRef ref) async {
-    return await _sendCommand(new Tap(ref)).then((Map<String, dynamic> _) => null);
+  /// Whether at least one widget identified by [finder] exists on the UI.
+  Future<bool> exists(SerializableFinder finder) async {
+    return await _sendCommand(new Exists(finder)).then((Map<String, dynamic> _) => null);
   }
 
   /// Tell the driver to perform a scrolling action.
@@ -209,13 +209,13 @@ class FlutterDriver {
   ///
   /// The move events are generated at a given [frequency] in Hz (or events per
   /// second). It defaults to 60Hz.
-  Future<Null> scroll(ObjectRef ref, double dx, double dy, Duration duration, {int frequency: 60}) async {
-    return await _sendCommand(new Scroll(ref, dx, dy, duration, frequency)).then((Map<String, dynamic> _) => null);
+  Future<Null> scroll(SerializableFinder finder, double dx, double dy, Duration duration, {int frequency: 60}) async {
+    return await _sendCommand(new Scroll(finder, dx, dy, duration, frequency)).then((Map<String, dynamic> _) => null);
   }
 
-  Future<String> getText(ObjectRef ref) async {
-    GetTextResult result = GetTextResult.fromJson(await _sendCommand(new GetText(ref)));
-    return result.text;
+  /// Returns the text in the `Text` widget located by [finder].
+  Future<String> getText(SerializableFinder finder) async {
+    return GetTextResult.fromJson(await _sendCommand(new GetText(finder))).text;
   }
 
   /// Starts recording performance traces.
@@ -358,3 +358,17 @@ Future<VMServiceClientConnection> _waitAndConnect(String url) async {
 
   return attemptConnection();
 }
+
+/// Provides convenient accessors to frequently used finders.
+class CommonFinders {
+  const CommonFinders._();
+
+  /// Finds [Text] widgets containing string equal to [text].
+  SerializableFinder text(String text) => new ByText(text);
+
+  /// Finds widgets by [key].
+  SerializableFinder byValueKey(dynamic key) => new ByValueKey(key);
+
+  /// Finds widgets with a tooltip with the given [message].
+  SerializableFinder byTooltip(String message) => new ByTooltipMessage(message);
+}

packages/flutter_driver/lib/src/extension.dart

@@ -47,34 +47,39 @@ typedef Future<Result> CommandHandlerCallback(Command c);
 /// Deserializes JSON map to a command object.
 typedef Command CommandDeserializerCallback(Map<String, String> params);
 
+/// Runs the finder and returns the [Element] found, or `null`.
+typedef Future<Element> FinderCallback(SerializableFinder finder);
+
 class FlutterDriverExtension {
   static final Logger _log = new Logger('FlutterDriverExtension');
 
   FlutterDriverExtension() {
-    _commandHandlers = {
+    _commandHandlers = <String, CommandHandlerCallback>{
       'get_health': getHealth,
-      'find': find,
       'tap': tap,
       'get_text': getText,
       'scroll': scroll,
     };
 
-    _commandDeserializers = {
+    _commandDeserializers = <String, CommandDeserializerCallback>{
       'get_health': GetHealth.deserialize,
-      'find': Find.deserialize,
       'tap': Tap.deserialize,
       'get_text': GetText.deserialize,
       'scroll': Scroll.deserialize,
     };
+
+    _finders = <String, FinderCallback>{
+      'ByValueKey': _findByValueKey,
+      'ByTooltipMessage': _findByTooltipMessage,
+      'ByText': _findByText,
+    };
   }
 
   final Instrumentation prober = new Instrumentation();
 
-  Map<String, CommandHandlerCallback> _commandHandlers =
-      <String, CommandHandlerCallback>{};
-
-  Map<String, CommandDeserializerCallback> _commandDeserializers =
-      <String, CommandDeserializerCallback>{};
+  Map<String, CommandHandlerCallback> _commandHandlers;
+  Map<String, CommandDeserializerCallback> _commandDeserializers;
+  Map<String, FinderCallback> _finders;
 
   Future<ServiceExtensionResponse> call(Map<String, String> params) async {
     try {
@@ -107,36 +112,18 @@ class FlutterDriverExtension {
 
   Future<Health> getHealth(GetHealth command) async => new Health(HealthStatus.ok);
 
-  Future<ObjectRef> find(Find command) async {
-    SearchSpecification searchSpec = command.searchSpec;
-    switch(searchSpec.runtimeType) {
-      case ByValueKey: return findByValueKey(searchSpec);
-      case ByTooltipMessage: return findByTooltipMessage(searchSpec);
-      case ByText: return findByText(searchSpec);
-    }
-    throw new DriverError('Unsupported search specification type ${searchSpec.runtimeType}');
-  }
-
-  /// Runs object [locator] repeatedly until it returns a non-`null` value.
-  ///
-  /// [descriptionGetter] describes the object to be waited for. It is used in
-  /// the warning printed should timeout happen.
-  Future<ObjectRef> _waitForObject(String descriptionGetter(), Object locator()) async {
-    Object object = await retry(locator, _kDefaultTimeout, _kDefaultPauseBetweenRetries, predicate: (Object object) {
+  /// Runs object [finder] repeatedly until it finds an [Element].
+  Future<Element> _waitForElement(String descriptionGetter(), Element locator()) {
+    return retry(locator, _kDefaultTimeout, _kDefaultPauseBetweenRetries, predicate: (dynamic object) {
       return object != null;
     }).catchError((Object error, Object stackTrace) {
       _log.warning('Timed out waiting for ${descriptionGetter()}');
       return null;
     });
-
-    ObjectRef elemRef = object != null
-      ? new ObjectRef(_registerObject(object))
-      : new ObjectRef.notFound();
-    return new Future<ObjectRef>.value(elemRef);
   }
 
-  Future<ObjectRef> findByValueKey(ByValueKey byKey) async {
-    return _waitForObject(
+  Future<Element> _findByValueKey(ByValueKey byKey) async {
+    return _waitForElement(
       () => 'element with key "${byKey.keyValue}" of type ${byKey.keyValueType}',
       () {
         return prober.findElementByKey(new ValueKey<dynamic>(byKey.keyValue));
@@ -144,8 +131,8 @@ class FlutterDriverExtension {
     );
   }
 
-  Future<ObjectRef> findByTooltipMessage(ByTooltipMessage byTooltipMessage) async {
-    return _waitForObject(
+  Future<Element> _findByTooltipMessage(ByTooltipMessage byTooltipMessage) async {
+    return _waitForElement(
       () => 'tooltip with message "${byTooltipMessage.text}" on it',
       () {
         return prober.findElement((Element element) {
@@ -160,22 +147,31 @@ class FlutterDriverExtension {
     );
   }
 
-  Future<ObjectRef> findByText(ByText byText) async {
-    return await _waitForObject(
+  Future<Element> _findByText(ByText byText) async {
+    return await _waitForElement(
       () => 'text "${byText.text}"',
       () {
         return prober.findText(byText.text);
       });
   }
 
+  Future<Element> _runFinder(SerializableFinder finder) {
+    FinderCallback cb = _finders[finder.finderType];
+
+    if (cb == null)
+      throw 'Unsupported finder type: ${finder.finderType}';
+
+    return cb(finder);
+  }
+
   Future<TapResult> tap(Tap command) async {
-    Element target = await _dereferenceOrDie(command.targetRef);
+    Element target = await _runFinder(command.finder);
     prober.tap(target);
     return new TapResult();
   }
 
   Future<ScrollResult> scroll(Scroll command) async {
-    Element target = await _dereferenceOrDie(command.targetRef);
+    Element target = await _runFinder(command.finder);
     final int totalMoves = command.duration.inMicroseconds * command.frequency ~/ Duration.MICROSECONDS_PER_SECOND;
     Offset delta = new Offset(command.dx, command.dy) / totalMoves.toDouble();
     Duration pause = command.duration ~/ totalMoves;
@@ -198,30 +194,9 @@ class FlutterDriverExtension {
   }
 
   Future<GetTextResult> getText(GetText command) async {
-    Element target = await _dereferenceOrDie(command.targetRef);
+    Element target = await _runFinder(command.finder);
     // TODO(yjbanov): support more ways to read text
     Text text = target.widget;
     return new GetTextResult(text.data);
   }
-
-  int _refCounter = 1;
-  final Map<String, Object> _objectRefs = <String, Object>{};
-  String _registerObject(Object obj) {
-    if (obj == null)
-      throw new ArgumentError('Cannot register null object');
-    String refKey = '${_refCounter++}';
-    _objectRefs[refKey] = obj;
-    return refKey;
-  }
-
-  dynamic _dereference(String reference) => _objectRefs[reference];
-
-  Future<dynamic> _dereferenceOrDie(String reference) {
-    Element object = _dereference(reference);
-
-    if (object == null)
-      return new Future<String>.error('Object reference not found ($reference).');
-
-    return new Future<Element>.value(object);
-  }
 }

packages/flutter_driver/lib/src/find.dart

@@ -11,46 +11,86 @@ DriverError _createInvalidKeyValueTypeError(String invalidType) {
   return new DriverError('Unsupported key value type $invalidType. Flutter Driver only supports ${_supportedKeyValueTypes.join(", ")}');
 }
 
-/// Command to find an element.
-class Find extends Command {
+/// A command aimed at an object to be located by [finder].
+///
+/// Implementations must provide a concrete [kind]. If additional data is
+/// required beyond the [finder] the implementation may override [serialize]
+/// and add more keys to the returned map.
+abstract class CommandWithTarget extends Command {
+  CommandWithTarget(this.finder) {
+    if (finder == null)
+      throw new DriverError('${this.runtimeType} target cannot be null');
+  }
+
+  /// Locates the object or objects targeted by this command.
+  final SerializableFinder finder;
+
+  /// This method is meant to be overridden if data in addition to [finder]
+  /// is serialized to JSON.
+  ///
+  /// Example:
+  ///
+  ///     Map<String, String> toJson() => super.toJson()..addAll({
+  ///       'foo': this.foo,
+  ///     });
   @override
-  final String kind = 'find';
+  Map<String, String> serialize() => finder.serialize();
+}
+
+/// Checks if the widget identified by the given finder exists.
+class Exists extends CommandWithTarget {
+  @override
+  final String kind = 'exists';
 
-  Find(this.searchSpec);
+  Exists(SerializableFinder finder) : super(finder);
 
-  final SearchSpecification searchSpec;
+  static Exists deserialize(Map<String, String> json) {
+    return new Exists(SerializableFinder.deserialize(json));
+  }
 
   @override
-  Map<String, String> serialize() => searchSpec.serialize();
+  Map<String, String> serialize() => super.serialize();
+}
 
-  static Find deserialize(Map<String, String> json) {
-    return new Find(SearchSpecification.deserialize(json));
+class ExistsResult extends Result {
+  ExistsResult(this.exists);
+
+  static ExistsResult fromJson(Map<String, dynamic> json) {
+    return new ExistsResult(json['exists']);
   }
+
+  /// Whether the widget was found on the UI or not.
+  final bool exists;
+
+  @override
+  Map<String, dynamic> toJson() => {
+    'exists': exists,
+  };
 }
 
 /// Describes how to the driver should search for elements.
-abstract class SearchSpecification {
-  String get searchSpecType;
+abstract class SerializableFinder {
+  String get finderType;
 
-  static SearchSpecification deserialize(Map<String, String> json) {
-    String searchSpecType = json['searchSpecType'];
-    switch(searchSpecType) {
+  static SerializableFinder deserialize(Map<String, String> json) {
+    String finderType = json['finderType'];
+    switch(finderType) {
       case 'ByValueKey': return ByValueKey.deserialize(json);
       case 'ByTooltipMessage': return ByTooltipMessage.deserialize(json);
       case 'ByText': return ByText.deserialize(json);
     }
-    throw new DriverError('Unsupported search specification type $searchSpecType');
+    throw new DriverError('Unsupported search specification type $finderType');
   }
 
   Map<String, String> serialize() => {
-    'searchSpecType': searchSpecType,
+    'finderType': finderType,
   };
 }
 
-/// Tells [Find] to search by tooltip text.
-class ByTooltipMessage extends SearchSpecification {
+/// Finds widgets by tooltip text.
+class ByTooltipMessage extends SerializableFinder {
   @override
-  final String searchSpecType = 'ByTooltipMessage';
+  final String finderType = 'ByTooltipMessage';
 
   ByTooltipMessage(this.text);
 
@@ -67,10 +107,10 @@ class ByTooltipMessage extends SearchSpecification {
   }
 }
 
-/// Tells [Find] to search for `Text` widget by text.
-class ByText extends SearchSpecification {
+/// Finds widgets by [text] inside a `Text` widget.
+class ByText extends SerializableFinder {
   @override
-  final String searchSpecType = 'ByText';
+  final String finderType = 'ByText';
 
   ByText(this.text);
 
@@ -86,10 +126,10 @@ class ByText extends SearchSpecification {
   }
 }
 
-/// Tells [Find] to search by `ValueKey`.
-class ByValueKey extends SearchSpecification {
+/// Finds widgets by `ValueKey`.
+class ByValueKey extends SerializableFinder {
   @override
-  final String searchSpecType = 'ByValueKey';
+  final String finderType = 'ByValueKey';
 
   ByValueKey(dynamic keyValue)
     : this.keyValue = keyValue,
@@ -132,14 +172,14 @@ class ByValueKey extends SearchSpecification {
 
 /// Command to read the text from a given element.
 class GetText extends CommandWithTarget {
-  /// [targetRef] identifies an element that contains a piece of text.
-  GetText(ObjectRef targetRef) : super(targetRef);
+  /// [finder] looks for an element that contains a piece of text.
+  GetText(SerializableFinder finder) : super(finder);
 
   @override
   final String kind = 'get_text';
 
   static GetText deserialize(Map<String, String> json) {
-    return new GetText(new ObjectRef(json['targetRef']));
+    return new GetText(SerializableFinder.deserialize(json));
   }
 
   @override

packages/flutter_driver/lib/src/gesture.dart

@@ -3,15 +3,16 @@
 // found in the LICENSE file.
 
 import 'message.dart';
+import 'find.dart';
 
 class Tap extends CommandWithTarget {
   @override
   final String kind = 'tap';
 
-  Tap(ObjectRef targetRef) : super(targetRef);
+  Tap(SerializableFinder finder) : super(finder);
 
   static Tap deserialize(Map<String, String> json) {
-    return new Tap(new ObjectRef(json['targetRef']));
+    return new Tap(SerializableFinder.deserialize(json));
   }
 
   @override
@@ -34,16 +35,16 @@ class Scroll extends CommandWithTarget {
   final String kind = 'scroll';
 
   Scroll(
-    ObjectRef targetRef,
+    SerializableFinder finder,
     this.dx,
     this.dy,
     this.duration,
     this.frequency
-  ) : super(targetRef);
+  ) : super(finder);
 
   static Scroll deserialize(Map<String, dynamic> json) {
     return new Scroll(
-      new ObjectRef(json['targetRef']),
+      SerializableFinder.deserialize(json),
       double.parse(json['dx']),
       double.parse(json['dy']),
       new Duration(microseconds: int.parse(json['duration'])),

packages/flutter_driver/lib/src/message.dart

@@ -2,8 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'error.dart';
-
 /// An object sent from the Flutter Driver to a Flutter application to instruct
 /// the application to perform a task.
 abstract class Command {
@@ -20,58 +18,3 @@ abstract class Result { // ignore: one_member_abstracts
   /// Serializes this message to a JSON map.
   Map<String, dynamic> toJson();
 }
-
-/// A serializable reference to an object that lives in the application isolate.
-class ObjectRef extends Result {
-  ObjectRef(this.objectReferenceKey);
-
-  ObjectRef.notFound() : this(null);
-
-  static ObjectRef fromJson(Map<String, dynamic> json) {
-    return json['objectReferenceKey'] != null
-      ? new ObjectRef(json['objectReferenceKey'])
-      : null;
-  }
-
-  /// Identifier used to dereference an object.
-  ///
-  /// This value is generated by the application-side isolate. Flutter driver
-  /// tests should not generate these keys.
-  final String objectReferenceKey;
-
-  @override
-  Map<String, dynamic> toJson() => {
-    'objectReferenceKey': objectReferenceKey,
-  };
-}
-
-/// A command aimed at an object represented by [targetRef].
-///
-/// Implementations must provide a concrete [kind]. If additional data is
-/// required beyond the [targetRef] the implementation may override [serialize]
-/// and add more keys to the returned map.
-abstract class CommandWithTarget extends Command {
-  CommandWithTarget(ObjectRef ref) : this.targetRef = ref?.objectReferenceKey {
-    if (ref == null)
-      throw new DriverError('${this.runtimeType} target cannot be null');
-
-    if (ref.objectReferenceKey == null)
-      throw new DriverError('${this.runtimeType} target reference cannot be null');
-  }
-
-  /// Refers to the object targeted by this command.
-  final String targetRef;
-
-  /// This method is meant to be overridden if data in addition to [targetRef]
-  /// is serialized to JSON.
-  ///
-  /// Example:
-  ///
-  ///     Map<String, String> toJson() => super.toJson()..addAll({
-  ///       'foo': this.foo,
-  ///     });
-  @override
-  Map<String, String> serialize() => <String, String>{
-    'targetRef': targetRef,
-  };
-}

packages/flutter_driver/test/flutter_driver_test.dart

@@ -7,7 +7,6 @@ import 'dart:async';
 import 'package:flutter_driver/src/driver.dart';
 import 'package:flutter_driver/src/error.dart';
 import 'package:flutter_driver/src/health.dart';
-import 'package:flutter_driver/src/message.dart';
 import 'package:flutter_driver/src/timeline.dart';
 import 'package:json_rpc_2/json_rpc_2.dart' as rpc;
 import 'package:mockito/mockito.dart';
@@ -120,27 +119,23 @@ void main() {
       await driver.close();
     });
 
-    group('findByValueKey', () {
+    group('ByValueKey', () {
       test('restricts value types', () async {
-        expect(driver.findByValueKey(null),
+        expect(() => find.byValueKey(null),
             throwsA(new isInstanceOf<DriverError>()));
       });
 
       test('finds by ValueKey', () async {
         when(mockIsolate.invokeExtension(any, any)).thenAnswer((Invocation i) {
           expect(i.positionalArguments[1], {
-            'command': 'find',
-            'searchSpecType': 'ByValueKey',
+            'command': 'tap',
+            'finderType': 'ByValueKey',
             'keyValueString': 'foo',
             'keyValueType': 'String'
           });
-          return new Future<Map<String, dynamic>>.value(<String, dynamic>{
-            'objectReferenceKey': '123',
-          });
+          return new Future<Null>.value();
         });
-        ObjectRef result = await driver.findByValueKey('foo');
-        expect(result, isNotNull);
-        expect(result.objectReferenceKey, '123');
+        await driver.tap(find.byValueKey('foo'));
       });
     });
 
@@ -149,20 +144,16 @@ void main() {
         expect(driver.tap(null), throwsA(new isInstanceOf<DriverError>()));
       });
 
-      test('requires a valid target reference', () async {
-        expect(driver.tap(new ObjectRef.notFound()),
-          throwsA(new isInstanceOf<DriverError>()));
-      });
-
       test('sends the tap command', () async {
         when(mockIsolate.invokeExtension(any, any)).thenAnswer((Invocation i) {
           expect(i.positionalArguments[1], <String, dynamic>{
             'command': 'tap',
-            'targetRef': '123'
+            'finderType': 'ByText',
+            'text': 'foo',
           });
           return new Future<Map<String, dynamic>>.value();
         });
-        await driver.tap(new ObjectRef('123'));
+        await driver.tap(find.text('foo'));
       });
     });
 
@@ -171,22 +162,19 @@ void main() {
         expect(driver.getText(null), throwsA(new isInstanceOf<DriverError>()));
       });
 
-      test('requires a valid target reference', () async {
-        expect(driver.getText(new ObjectRef.notFound()),
-          throwsA(new isInstanceOf<DriverError>()));
-      });
-
       test('sends the getText command', () async {
         when(mockIsolate.invokeExtension(any, any)).thenAnswer((Invocation i) {
           expect(i.positionalArguments[1], <String, dynamic>{
             'command': 'get_text',
-            'targetRef': '123'
+            'finderType': 'ByValueKey',
+            'keyValueString': '123',
+            'keyValueType': 'int'
           });
           return new Future<Map<String, dynamic>>.value({
             'text': 'hello'
           });
         });
-        String result = await driver.getText(new ObjectRef('123'));
+        String result = await driver.getText(find.byValueKey(123));
         expect(result, 'hello');
       });
     });

packages/flutter_tools/templates/driver/main_test.dart.tmpl

@@ -23,14 +23,14 @@ void main() {
 
     test('tap on the floating action button; verify counter', () async {
       // Find floating action button (fab) to tap on
-      ObjectRef fab = await driver.findByTooltipMessage('Increment');
-      expect(fab, isNotNull);
+      SerializableFinder fab = find.byTooltip('Increment');
+      expect(await driver.exists(fab), isTrue);
 
       // Tap on the fab
       await driver.tap(fab);
 
       // Wait for text to change to the desired value
-      expect(await driver.findByText('Button tapped 1 time.'), isNotNull);
+      expect(await driver.exists(find.text('Button tapped 1 time.')), isTrue);
     });
   });
 }