100% doc coverage in package:flutter_driver (#6738)

packages/flutter_driver/lib/src/driver.dart

@@ -6,6 +6,7 @@ import 'dart:async';
 import 'dart:convert';
 import 'dart:io';
 import 'package:json_rpc_2/json_rpc_2.dart' as rpc;
+import 'package:meta/meta.dart';
 import 'package:vm_service_client/vm_service_client.dart';
 import 'package:web_socket_channel/io.dart';
 
@@ -17,8 +18,34 @@ import 'input.dart';
 import 'message.dart';
 import 'timeline.dart';
 
+/// Timeline stream identifier.
 enum TimelineStream {
-  all, api, compiler, dart, debugger, embedder, gc, isolate, vm
+  /// A meta-identifier that instructs the Dart VM to record all streams.
+  all,
+
+  /// Marks events related to calls made via Dart's C API.
+  api,
+
+  /// Marks events from the Dart VM's JIT compiler.
+  compiler,
+
+  /// Marks events emitted using the `dart:developer` API.
+  dart,
+
+  /// Marks events from the Dart VM debugger.
+  debugger,
+
+  /// Marks events emitted using the `dart_tools_api.h` C API.
+  embedder,
+
+  /// Marks events from the garbage collector.
+  gc,
+
+  /// Marks events related to message passing between Dart isolates.
+  isolate,
+
+  /// Marks internal VM events.
+  vm,
 }
 
 const List<TimelineStream> _defaultStreams = const <TimelineStream>[TimelineStream.all];
@@ -62,6 +89,9 @@ typedef dynamic EvaluatorFunction();
 
 /// Drives a Flutter Application running in another process.
 class FlutterDriver {
+  /// Creates a driver that uses a connection provided by the given
+  /// [_serviceClient], [_peer] and [_appIsolate].
+  @visibleForTesting
   FlutterDriver.connectedTo(this._serviceClient, this._peer, this._appIsolate);
 
   static const String _kFlutterExtensionMethod = 'ext.flutter.driver';
@@ -316,6 +346,9 @@ class FlutterDriver {
   ///
   /// This is merely a convenience wrapper on top of [startTracing] and
   /// [stopTracingAndDownloadTimeline].
+  ///
+  /// [streams] limits the recorded timeline event streams to only the ones
+  /// listed. By default, all streams are recorded.
   Future<Timeline> traceAction(Future<dynamic> action(), { List<TimelineStream> streams: _defaultStreams }) async {
     await startTracing(streams: streams);
     await action();
@@ -334,6 +367,7 @@ class FlutterDriver {
 }
 
 /// Encapsulates connection information to an instance of a Flutter application.
+@visibleForTesting
 class VMServiceClientConnection {
   /// Use this for structured access to the VM service's public APIs.
   final VMServiceClient client;
@@ -344,6 +378,7 @@ class VMServiceClientConnection {
   /// caution.
   final rpc.Peer peer;
 
+  /// Creates an instance of this class given a [client] and a [peer].
   VMServiceClientConnection(this.client, this.peer);
 }
 

packages/flutter_driver/lib/src/error.dart

@@ -7,12 +7,17 @@ import 'dart:io' show stderr;
 
 /// Standard error thrown by Flutter Driver API.
 class DriverError extends Error {
+  /// Create an error with a [message] and (optionally) the [originalError] and
+  /// [originalStackTrace] that caused it.
   DriverError(this.message, [this.originalError, this.originalStackTrace]);
 
   /// Human-readable error message.
   final String message;
 
+  /// The error object that was caught and wrapped by this error object.
   final dynamic originalError;
+
+  /// The stack trace that was caught and wrapped by this error object.
   final dynamic originalStackTrace;
 
   @override
@@ -47,44 +52,99 @@ void _log(LogLevel level, String loggerName, Object message) {
 final Stream<LogRecord> flutterDriverLog = _logger.stream;
 
 /// Severity of a log entry.
-enum LogLevel { trace, info, warning, error, critical }
+enum LogLevel {
+  /// Messages used to supplement the higher-level messages with more details.
+  ///
+  /// This will likely produce a lot of output.
+  trace,
+
+  /// Informational messages that do not indicate a problem.
+  info,
+
+  /// A potential problem.
+  warning,
+
+  /// A certain problem but the program will attempt to continue.
+  error,
+
+  /// A critical problem; the program will attempt to quit immediately.
+  critical,
+}
 
 /// A log entry.
 class LogRecord {
   const LogRecord._(this.level, this.loggerName, this.message);
 
+  /// The severity of the log record.
   final LogLevel level;
+
+  /// The name of the logger that logged the message.
   final String loggerName;
+
+  /// The log message.
+  ///
+  /// The message should be a normal and complete sentence ending with a period.
+  /// It is OK to omit the subject in the message to imply [loggerName]. It is
+  /// also OK to omit article, such as "the" and "a".
+  ///
+  /// Example: if [loggerName] is "FlutterDriver" and [message] is "Failed to
+  /// connect to application." then this log record means that FlutterDriver
+  /// failed to connect to the application.
   final String message;
 
+  /// Short description of the log level.
+  ///
+  /// It is meant to be read by humans. There's no guarantee that this value is
+  /// stable enough to be parsed by machines.
   String get levelDescription => level.toString().split(".").last;
 
   @override
   String toString() => '[${levelDescription.padRight(5)}] $loggerName: $message';
 }
 
-/// Package-private; users should use other public logging libraries.
+/// Logger used internally by Flutter Driver to avoid mandating any specific
+/// logging library.
+///
+/// By default the output from this logger is printed to [stderr]. However, a
+/// subscriber to the [flutterDriverLog] stream may redirect the log records
+/// elsewhere, including other logging API. The logger stops sending messages to
+/// [stderr] upon first subscriber.
+///
+/// This class is package-private. Flutter users should use other public logging
+/// libraries.
 class Logger {
+  /// Creates a new logger.
   Logger(this.name);
 
+  /// Identifies the part of the system that emits message into this object.
+  ///
+  /// It is common for [name] to be used as an implicit subject of an action
+  /// described in a log message. For example, if you emit message "failed" and
+  /// [name] is "FlutterDriver", the meaning of the message should be understood
+  /// as "FlutterDriver failed". See also [LogRecord.message].
   final String name;
 
+  /// Emits a [LogLevel.trace] record into `this` logger.
   void trace(Object message) {
     _log(LogLevel.trace, name, message);
   }
 
+  /// Emits a [LogLevel.info] record into `this` logger.
   void info(Object message) {
     _log(LogLevel.info, name, message);
   }
 
+  /// Emits a [LogLevel.warning] record into `this` logger.
   void warning(Object message) {
     _log(LogLevel.warning, name, message);
   }
 
+  /// Emits a [LogLevel.error] record into `this` logger.
   void error(Object message) {
     _log(LogLevel.error, name, message);
   }
 
+  /// Emits a [LogLevel.critical] record into `this` logger.
   void critical(Object message) {
     _log(LogLevel.critical, name, message);
   }

packages/flutter_driver/lib/src/extension.dart

@@ -25,7 +25,7 @@ class _DriverBinding extends WidgetsFlutterBinding { // TODO(ianh): refactor so
   @override
   void initServiceExtensions() {
     super.initServiceExtensions();
-    FlutterDriverExtension extension = new FlutterDriverExtension();
+    _FlutterDriverExtension extension = new _FlutterDriverExtension._();
     registerServiceExtension(
       name: _extensionMethodName,
       callback: extension.call
@@ -55,10 +55,10 @@ typedef Command CommandDeserializerCallback(Map<String, String> params);
 /// Runs the finder and returns the [Element] found, or `null`.
 typedef Finder FinderConstructor(SerializableFinder finder);
 
-class FlutterDriverExtension {
+class _FlutterDriverExtension {
   static final Logger _log = new Logger('FlutterDriverExtension');
 
-  FlutterDriverExtension() {
+  _FlutterDriverExtension._() {
     _commandHandlers.addAll(<String, CommandHandlerCallback>{
       'get_health': _getHealth,
       'tap': _tap,
@@ -88,11 +88,21 @@ class FlutterDriverExtension {
     });
   }
 
-  final WidgetController prober = new WidgetController(WidgetsBinding.instance);
+  final WidgetController _prober = new WidgetController(WidgetsBinding.instance);
   final Map<String, CommandHandlerCallback> _commandHandlers = <String, CommandHandlerCallback>{};
   final Map<String, CommandDeserializerCallback> _commandDeserializers = <String, CommandDeserializerCallback>{};
   final Map<String, FinderConstructor> _finders = <String, FinderConstructor>{};
 
+  /// Processes a driver command configured by [params] and returns a result
+  /// as an arbitrary JSON object.
+  ///
+  /// [params] must contain key "command" whose value is a string that
+  /// identifies the kind of the command and its corresponding
+  /// [CommandDeserializerCallback]. Other keys and values are specific to the
+  /// concrete implementation of [Command] and [CommandDeserializerCallback].
+  ///
+  /// The returned JSON is command specific. Generally the caller deserializes
+  /// the result into a subclass of [Result], but that's not strictly required.
   Future<Map<String, dynamic>> call(Map<String, String> params) async {
     try {
       String commandKind = params['command'];
@@ -181,7 +191,7 @@ class FlutterDriverExtension {
 
   Future<TapResult> _tap(Command command) async {
     Tap tapCommand = command;
-    await prober.tap(await _waitForElement(_createFinder(tapCommand.finder)));
+    await _prober.tap(await _waitForElement(_createFinder(tapCommand.finder)));
     return new TapResult();
   }
 
@@ -199,20 +209,20 @@ class FlutterDriverExtension {
     final int totalMoves = scrollCommand.duration.inMicroseconds * scrollCommand.frequency ~/ Duration.MICROSECONDS_PER_SECOND;
     Offset delta = new Offset(scrollCommand.dx, scrollCommand.dy) / totalMoves.toDouble();
     Duration pause = scrollCommand.duration ~/ totalMoves;
-    Point startLocation = prober.getCenter(target);
+    Point startLocation = _prober.getCenter(target);
     Point currentLocation = startLocation;
     TestPointer pointer = new TestPointer(1);
     HitTestResult hitTest = new HitTestResult();
 
-    prober.binding.hitTest(hitTest, startLocation);
+    _prober.binding.hitTest(hitTest, startLocation);
-    prober.binding.dispatchEvent(pointer.down(startLocation), hitTest);
+    _prober.binding.dispatchEvent(pointer.down(startLocation), hitTest);
     await new Future<Null>.value();  // so that down and move don't happen in the same microtask
     for (int moves = 0; moves < totalMoves; moves++) {
       currentLocation = currentLocation + delta;
-      prober.binding.dispatchEvent(pointer.move(currentLocation), hitTest);
+      _prober.binding.dispatchEvent(pointer.move(currentLocation), hitTest);
       await new Future<Null>.delayed(pause);
     }
-    prober.binding.dispatchEvent(pointer.up(), hitTest);
+    _prober.binding.dispatchEvent(pointer.up(), hitTest);
 
     return new ScrollResult();
   }

packages/flutter_driver/lib/src/find.dart

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+import 'package:meta/meta.dart';
+
 import 'error.dart';
 import 'message.dart';
 
@@ -17,6 +19,7 @@ DriverError _createInvalidKeyValueTypeError(String invalidType) {
 /// required beyond the [finder] the implementation may override [serialize]
 /// and add more keys to the returned map.
 abstract class CommandWithTarget extends Command {
+  /// Constructs this command given a [finder].
   CommandWithTarget(this.finder) {
     if (finder == null)
       throw new DriverError('${this.runtimeType} target cannot be null');
@@ -42,11 +45,20 @@ class WaitFor extends CommandWithTarget {
   @override
   final String kind = 'waitFor';
 
+  /// Creates a command that waits for the widget identified by [finder] to
+  /// appear within the [timeout] amount of time.
+  ///
+  /// If [timeout] is not specified the command times out after 5 seconds.
   WaitFor(SerializableFinder finder, {this.timeout})
       : super(finder);
 
+  /// The maximum amount of time to wait for the [finder] to locate the desired
+  /// widgets before timing out the command.
+  ///
+  /// Defaults to 5 seconds.
   final Duration timeout;
 
+  /// Deserializes the command from JSON generated by [serialize].
   static WaitFor deserialize(Map<String, String> json) {
     Duration timeout = json['timeout'] != null
       ? new Duration(milliseconds: int.parse(json['timeout']))
@@ -66,9 +78,9 @@ class WaitFor extends CommandWithTarget {
   }
 }
 
+/// The result of a [WaitFor] command.
 class WaitForResult extends Result {
-  WaitForResult();
+  /// Deserializes the result from JSON.
-
   static WaitForResult fromJson(Map<String, dynamic> json) {
     return new WaitForResult();
   }
@@ -79,8 +91,10 @@ class WaitForResult extends Result {
 
 /// Describes how to the driver should search for elements.
 abstract class SerializableFinder {
+  /// Identifies the type of finder to be used by the driver extension.
   String get finderType;
 
+  /// Deserializes a finder from JSON generated by [serialize].
   static SerializableFinder deserialize(Map<String, String> json) {
     String finderType = json['finderType'];
     switch(finderType) {
@@ -91,6 +105,11 @@ abstract class SerializableFinder {
     throw new DriverError('Unsupported search specification type $finderType');
   }
 
+  /// Serializes common fields to JSON.
+  ///
+  /// Methods that override [serialize] are expected to call `super.serialize`
+  /// and add more fields to the returned [Map].
+  @mustCallSuper
   Map<String, String> serialize() => <String, String>{
     'finderType': finderType,
   };
@@ -101,6 +120,7 @@ class ByTooltipMessage extends SerializableFinder {
   @override
   final String finderType = 'ByTooltipMessage';
 
+  /// Creates a tooltip finder given the tooltip's message [text].
   ByTooltipMessage(this.text);
 
   /// Tooltip message text.
@@ -111,6 +131,7 @@ class ByTooltipMessage extends SerializableFinder {
     'text': text,
   });
 
+  /// Deserializes the finder from JSON generated by [serialize].
   static ByTooltipMessage deserialize(Map<String, String> json) {
     return new ByTooltipMessage(json['text']);
   }
@@ -121,8 +142,10 @@ class ByText extends SerializableFinder {
   @override
   final String finderType = 'ByText';
 
+  /// Creates a text finder given the text.
   ByText(this.text);
 
+  /// The text that appears inside the `Text` widget.
   final String text;
 
   @override
@@ -130,6 +153,7 @@ class ByText extends SerializableFinder {
     'text': text,
   });
 
+  /// Deserializes the finder from JSON generated by [serialize].
   static ByText deserialize(Map<String, String> json) {
     return new ByText(json['text']);
   }
@@ -140,6 +164,7 @@ class ByValueKey extends SerializableFinder {
   @override
   final String finderType = 'ByValueKey';
 
+  /// Creates a finder given the key value.
   ByValueKey(dynamic keyValue)
     : this.keyValue = keyValue,
       this.keyValueString = '$keyValue',
@@ -165,6 +190,7 @@ class ByValueKey extends SerializableFinder {
     'keyValueType': keyValueType,
   });
 
+  /// Deserializes the finder from JSON generated by [serialize].
   static ByValueKey deserialize(Map<String, String> json) {
     String keyValueString = json['keyValueString'];
     String keyValueType = json['keyValueType'];
@@ -187,6 +213,7 @@ class GetText extends CommandWithTarget {
   @override
   final String kind = 'get_text';
 
+  /// Deserializes the command from JSON generated by [serialize].
   static GetText deserialize(Map<String, String> json) {
     return new GetText(SerializableFinder.deserialize(json));
   }
@@ -195,11 +222,15 @@ class GetText extends CommandWithTarget {
   Map<String, String> serialize() => super.serialize();
 }
 
+/// The result of the [GetText] command.
 class GetTextResult extends Result {
+  /// Creates a result with the given [text].
   GetTextResult(this.text);
 
+  /// The text extracted by the [GetText] command.
   final String text;
 
+  /// Deserializes the result from JSON.
   static GetTextResult fromJson(Map<String, dynamic> json) {
     return new GetTextResult(json['text']);
   }

packages/flutter_driver/lib/src/gesture.dart

@@ -5,12 +5,15 @@
 import 'message.dart';
 import 'find.dart';
 
+/// Taps on a target widget located by [finder].
 class Tap extends CommandWithTarget {
   @override
   final String kind = 'tap';
 
+  /// Creates a tap command to tap on a widget located by [finder].
   Tap(SerializableFinder finder) : super(finder);
 
+  /// Deserializes this command from JSON generated by [serialize].
   static Tap deserialize(Map<String, String> json) {
     return new Tap(SerializableFinder.deserialize(json));
   }
@@ -19,7 +22,9 @@ class Tap extends CommandWithTarget {
   Map<String, String> serialize() => super.serialize();
 }
 
+/// The result of a [Tap] command.
 class TapResult extends Result {
+  /// Deserializes this result from JSON.
   static TapResult fromJson(Map<String, dynamic> json) {
     return new TapResult();
   }
@@ -34,6 +39,8 @@ class Scroll extends CommandWithTarget {
   @override
   final String kind = 'scroll';
 
+  /// Creates a scroll command that will attempt to scroll a scrollable view by
+  /// dragging a widget located by the given [finder].
   Scroll(
     SerializableFinder finder,
     this.dx,
@@ -42,6 +49,7 @@ class Scroll extends CommandWithTarget {
     this.frequency
   ) : super(finder);
 
+  /// Deserializes this command from JSON generated by [serialize].
   static Scroll deserialize(Map<String, dynamic> json) {
     return new Scroll(
       SerializableFinder.deserialize(json),
@@ -73,20 +81,9 @@ class Scroll extends CommandWithTarget {
   });
 }
 
-/// Command the driver to ensure that the element represented by [finder]
+/// The result of a [Scroll] command.
-/// has been scrolled completely into view.
-class ScrollIntoView extends CommandWithTarget {
-  @override
-  final String kind = 'scrollIntoView';
-
-  ScrollIntoView(SerializableFinder finder) : super(finder);
-
-  static ScrollIntoView deserialize(Map<String, dynamic> json) {
-    return new ScrollIntoView(SerializableFinder.deserialize(json));
-  }
-}
-
 class ScrollResult extends Result {
+  /// Deserializes this result from JSON.
   static ScrollResult fromJson(Map<String, dynamic> json) {
     return new ScrollResult();
   }
@@ -94,3 +91,24 @@ class ScrollResult extends Result {
   @override
   Map<String, dynamic> toJson() => <String, dynamic>{};
 }
+
+/// Command the driver to ensure that the element represented by [finder]
+/// has been scrolled completely into view.
+class ScrollIntoView extends CommandWithTarget {
+  @override
+  final String kind = 'scrollIntoView';
+
+  /// Creates this command given a [finder] used to locate the widget to be
+  /// scrolled into view.
+  ScrollIntoView(SerializableFinder finder) : super(finder);
+
+  /// Deserializes this command from JSON generated by [serialize].
+  static ScrollIntoView deserialize(Map<String, dynamic> json) {
+    return new ScrollIntoView(SerializableFinder.deserialize(json));
+  }
+
+  // This is here just to be clear that this command isn't adding any extra
+  // fields.
+  @override
+  Map<String, String> serialize() => super.serialize();
+}

packages/flutter_driver/lib/src/health.dart

@@ -10,6 +10,7 @@ class GetHealth implements Command {
   @override
   final String kind = 'get_health';
 
+  /// Deserializes the command from JSON generated by [serialize].
   static GetHealth deserialize(Map<String, String> json) => new GetHealth();
 
   @override
@@ -30,10 +31,12 @@ final EnumIndex<HealthStatus> _healthStatusIndex =
 
 /// Application health status.
 class Health extends Result {
+  /// Creates a [Health] object with the given [status].
   Health(this.status) {
     assert(status != null);
   }
 
+  /// Deserializes the result from JSON.
   static Health fromJson(Map<String, dynamic> json) {
     return new Health(_healthStatusIndex.lookupBySimpleName(json['status']));
   }

packages/flutter_driver/lib/src/input.dart

@@ -5,14 +5,21 @@
 import 'message.dart';
 import 'find.dart';
 
+/// Sets [text] in a text input widget.
 class SetInputText extends CommandWithTarget {
   @override
   final String kind = 'setInputText';
 
+  /// Creates a command.
+  ///
+  /// [finder] identifies the text input widget. [text] is the string that is
+  /// set as the value of the text input.
   SetInputText(SerializableFinder finder, this.text) : super(finder);
 
+  /// The value of the text input to set.
   final String text;
 
+  /// Deserializes this command from JSON generated by [serialize].
   static SetInputText deserialize(Map<String, dynamic> json) {
     String text = json['text'];
     return new SetInputText(SerializableFinder.deserialize(json), text);
@@ -26,7 +33,9 @@ class SetInputText extends CommandWithTarget {
   }
 }
 
+/// The result of a [SetInputText] command.
 class SetInputTextResult extends Result {
+  /// Deserializes this result from JSON.
   static SetInputTextResult fromJson(Map<String, dynamic> json) {
     return new SetInputTextResult();
   }
@@ -35,22 +44,32 @@ class SetInputTextResult extends Result {
   Map<String, dynamic> toJson() => <String, dynamic>{};
 }
 
+/// Submits text entered in a text input widget.
+///
+/// The definition of submitting input text can be found
+/// [here](https://docs.flutter.io/flutter/material/Input/onSubmitted.html).
 class SubmitInputText extends CommandWithTarget {
   @override
   final String kind = 'submitInputText';
 
+  /// Create a command that submits text on input widget identified by [finder].
   SubmitInputText(SerializableFinder finder) : super(finder);
 
+  /// Deserializes this command from JSON generated by [serialize].
   static SubmitInputText deserialize(Map<String, dynamic> json) {
     return new SubmitInputText(SerializableFinder.deserialize(json));
   }
 }
 
+/// The result of a [SubmitInputText] command.
 class SubmitInputTextResult extends Result {
+  /// Creates a result with [text] as the submitted value.
   SubmitInputTextResult(this.text);
 
+  /// The submitted value.
   final String text;
 
+  /// Deserializes this result from JSON.
   static SubmitInputTextResult fromJson(Map<String, dynamic> json) {
     return new SubmitInputTextResult(json['text']);
   }

packages/flutter_driver/lib/src/timeline.dart

@@ -3,12 +3,13 @@
 // found in the LICENSE file.
 
 /// Timeline data recorded by the Flutter runtime.
-///
-/// The data is in the `chrome://tracing` format. It can be saved to a file
-/// and loaded in Chrome for visual inspection.
-///
-/// See https://docs.google.com/document/d/1CvAClvFfyA5R-PhYUmn5OOQtYMH4h6I0nSsKchNAySU/preview
 class Timeline {
+  /// Creates a timeline given JSON-encoded timeline data.
+  ///
+  /// [json] is in the `chrome://tracing` format. It can be saved to a file
+  /// and loaded in Chrome for visual inspection.
+  ///
+  /// See https://docs.google.com/document/d/1CvAClvFfyA5R-PhYUmn5OOQtYMH4h6I0nSsKchNAySU/preview
   factory Timeline.fromJson(Map<String, dynamic> json) {
     return new Timeline._(json, _parseEvents(json));
   }
@@ -24,6 +25,7 @@ class Timeline {
 
 /// A single timeline event.
 class TimelineEvent {
+  /// Creates a timeline event given JSON-encoded event data.
   factory TimelineEvent(Map<String, dynamic> json) {
     return new TimelineEvent._(
       json,

packages/flutter_driver/lib/src/timeline_summary.dart

@@ -19,8 +19,9 @@ final JsonEncoder _prettyEncoder = new JsonEncoder.withIndent('  ');
 /// phase. Anything past that is in the danger of missing the frame as 60FPS.
 const Duration kBuildBudget = const Duration(milliseconds: 8);
 
-/// Extracts statistics from the event loop timeline.
+/// Extracts statistics from a [Timeline].
 class TimelineSummary {
+  /// Creates a timeline summary given a full timeline object.
   TimelineSummary.summarize(this._timeline);
 
   final Timeline _timeline;
@@ -142,6 +143,7 @@ class TimedEvent {
   /// The duration of the event.
   final Duration duration;
 
+  /// Creates a timed event given begin and end timestamps in microseconds.
   TimedEvent(int beginTimeMicros, int endTimeMicros)
     : this.beginTimeMicros = beginTimeMicros,
       this.endTimeMicros = endTimeMicros,