fix up analysis for Dart in Engine (flutter#7404)

* fix up analysis for Dart in Engine, particularly for tests

Author: dnfield

analysis_options.yaml

@@ -10,16 +10,14 @@
 #    private fields, especially on the Window object):
 
 analyzer:
-  language:
-    enableStrictCallChecks: true
-    enableSuperMixins: true
   strong-mode:
     implicit-dynamic: false
   errors:
     # treat missing required parameters as a warning (not a hint)
     missing_required_param: warning
     # treat missing returns as a warning (not a hint)
     missing_return: warning
+    native_function_body_in_non_sdk_code: ignore
     # allow having TODOs in the code
     todo: ignore
   # `flutter analyze` (without `--watch`) just ignores directories
@@ -94,7 +92,6 @@ linter:
     # - parameter_assignments # we do this commonly
     - prefer_adjacent_string_concatenation
     - prefer_asserts_in_initializer_lists
-    - prefer_bool_in_asserts
     - prefer_collection_literals
     - prefer_conditional_assignment
     - prefer_const_constructors

ci/analyze.sh

@@ -4,13 +4,7 @@ RESULTS=`dartanalyzer                                                          \
   --options flutter/analysis_options.yaml                                      \
   out/host_debug_unopt/gen/sky/bindings/dart_ui/ui.dart                        \
   2>&1                                                                         \
-  | grep -v "Native functions can only be declared in the SDK and code that is loaded through native extensions" \
-  | grep -Ev "The function '.+' (is not|isn't) used"                           \
-  | grep -Ev "The top level variable '.+' isn't used"                          \
-  | grep -Ev "Undefined name 'main'"                                           \
-  | grep -v "The library 'dart:_internal' is internal"                         \
-  | grep -Ev "Unused import.+ui\.dart"                                         \
-  | grep -Ev "[0-9]+ errors.*found\."                                          \
+  | grep -Ev "No issues found!"                                          \
   | grep -Ev "Analyzing.+out/host_debug_unopt/gen/sky/bindings/dart_ui/ui\.dart"`
 
 echo "$RESULTS"

lib/ui/hooks.dart

@@ -2,17 +2,22 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+// TODO(dnfield): Remove unused_import ignores when https://github.com/dart-lang/sdk/issues/35164 is resolved.
+
 part of dart.ui;
 
+// ignore: unused_element
 String _decodeUTF8(ByteData message) {
   return message != null ? utf8.decoder.convert(message.buffer.asUint8List()) : null;
 }
 
+// ignore: unused_element
 dynamic _decodeJSON(String message) {
   return message != null ? json.decode(message) : null;
 }
 
 @pragma('vm:entry-point')
+// ignore: unused_element
 void _updateWindowMetrics(double devicePixelRatio,
                           double width,
                           double height,
@@ -50,9 +55,11 @@ String _localeClosure() {
 }
 
 @pragma('vm:entry-point')
+// ignore: unused_element
 _LocaleClosure _getLocaleClosure() => _localeClosure;
 
 @pragma('vm:entry-point')
+// ignore: unused_element
 void _updateLocales(List<String> locales) {
   const int stringsPerLocale = 4;
   final int numLocales = locales.length ~/ stringsPerLocale;
@@ -71,6 +78,7 @@ void _updateLocales(List<String> locales) {
 }
 
 @pragma('vm:entry-point')
+// ignore: unused_element
 void _updateUserSettingsData(String jsonData) {
   final Map<String, dynamic> data = json.decode(jsonData);
   if (data.isEmpty) {
@@ -90,12 +98,14 @@ void _updateAlwaysUse24HourFormat(bool alwaysUse24HourFormat) {
 }
 
 @pragma('vm:entry-point')
+// ignore: unused_element
 void _updateSemanticsEnabled(bool enabled) {
   window._semanticsEnabled = enabled;
   _invoke(window.onSemanticsEnabledChanged, window._onSemanticsEnabledChangedZone);
 }
 
 @pragma('vm:entry-point')
+// ignore: unused_element
 void _updateAccessibilityFeatures(int values) {
   final AccessibilityFeatures newFeatures = new AccessibilityFeatures._(values);
   if (newFeatures == window._accessibilityFeatures)
@@ -122,12 +132,14 @@ void _dispatchPlatformMessage(String name, ByteData data, int responseId) {
 }
 
 @pragma('vm:entry-point')
+// ignore: unused_element
 void _dispatchPointerDataPacket(ByteData packet) {
   if (window.onPointerDataPacket != null)
     _invoke1<PointerDataPacket>(window.onPointerDataPacket, window._onPointerDataPacketZone, _unpackPointerDataPacket(packet));
 }
 
 @pragma('vm:entry-point')
+// ignore: unused_element
 void _dispatchSemanticsAction(int id, int action, ByteData args) {
   _invoke3<int, SemanticsAction, ByteData>(
     window.onSemanticsAction,
@@ -139,11 +151,13 @@ void _dispatchSemanticsAction(int id, int action, ByteData args) {
 }
 
 @pragma('vm:entry-point')
+// ignore: unused_element
 void _beginFrame(int microseconds) {
   _invoke1<Duration>(window.onBeginFrame, window._onBeginFrameZone, new Duration(microseconds: microseconds));
 }
 
 @pragma('vm:entry-point')
+// ignore: unused_element
 void _drawFrame() {
   _invoke(window.onDrawFrame, window._onDrawFrameZone);
 }
@@ -177,6 +191,7 @@ void _invoke1<A>(void callback(A a), Zone zone, A arg) {
 }
 
 /// Invokes [callback] inside the given [zone] passing it [arg1] and [arg2].
+// ignore: unused_element
 void _invoke2<A1, A2>(void callback(A1 a1, A2 a2), Zone zone, A1 arg1, A2 arg2) {
   if (callback == null)
     return;

lib/ui/natives.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.
 
+// TODO(dnfield): remove unused_element ignores when https://github.com/dart-lang/sdk/issues/35164 is resolved.
+
 part of dart.ui;
 
 // Corelib 'print' implementation.
@@ -28,7 +30,7 @@ Future<developer.ServiceExtensionResponse> _scheduleFrame(
 }
 
 @pragma('vm:entry-point')
-void _setupHooks() {
+void _setupHooks() {  // ignore: unused_element
   assert(() {
     // In debug mode, register the schedule frame extension.
     developer.registerExtension('ext.ui.window.scheduleFrame', _scheduleFrame);
@@ -67,9 +69,9 @@ int _getCallbackHandle(Function closure) native 'GetCallbackHandle';
 Function _getCallbackFromHandle(int handle) native 'GetCallbackFromHandle';
 
 // Required for gen_snapshot to work correctly.
-int _isolateId;
+int _isolateId; // ignore: unused_element
 
 @pragma('vm:entry-point')
-Function _getPrintClosure() => _print;
+Function _getPrintClosure() => _print;  // ignore: unused_element
 @pragma('vm:entry-point')
-Function _getScheduleMicrotaskClosure() => _scheduleMicrotask;
+Function _getScheduleMicrotaskClosure() => _scheduleMicrotask; // ignore: unused_element

lib/ui/ui.dart

@@ -11,12 +11,12 @@
 /// text, layout, and rendering subsystems.
 library dart.ui;
 
-import 'dart:_internal' hide Symbol;
+import 'dart:_internal' hide Symbol; // ignore: import_internal_library, unused_import
 import 'dart:async';
 import 'dart:collection' as collection;
 import 'dart:convert';
 import 'dart:developer' as developer;
-import 'dart:io';
+import 'dart:io'; // ignore: unused_import
 import 'dart:isolate' show SendPort;
 import 'dart:math' as math;
 import 'dart:nativewrappers';

runtime/fixtures/simple_main.dart

@@ -3,5 +3,5 @@
 // found in the LICENSE file.
 
 void main() {
-  print("Hello");
+  print('Hello');
 }

testing/dart/canvas_test.dart

@@ -2,51 +2,52 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'dart:ui';
 import 'dart:typed_data';
+import 'dart:ui';
 
 import 'package:test/test.dart';
 
-typedef void CanvasCallback(Canvas canvas);
+typedef CanvasCallback = void Function(Canvas canvas);
 
 void testCanvas(CanvasCallback callback) {
   try {
     callback(Canvas(PictureRecorder(), Rect.fromLTRB(0.0, 0.0, 0.0, 0.0)));
-  } catch (error) { }
+  } catch (error) { } // ignore: empty_catches
 }
 
 void main() {
-  test("canvas APIs should not crash", () {
-    Paint paint = Paint();
-    Rect rect = Rect.fromLTRB(double.nan, double.nan, double.nan, double.nan);
-    RRect rrect = RRect.fromRectAndCorners(rect);
-    Offset offset = Offset(double.nan, double.nan);
-    Path path = Path();
-    Color color = Color(0);
-    Paragraph paragraph = ParagraphBuilder(ParagraphStyle()).build();
+  test('canvas APIs should not crash', () {
+    final Paint paint = Paint();
+    final Rect rect = Rect.fromLTRB(double.nan, double.nan, double.nan, double.nan);
+    final RRect rrect = RRect.fromRectAndCorners(rect);
+    const Offset offset = Offset(double.nan, double.nan);
+    final Path path = Path();
+    const Color color = Color(0);
+    final Paragraph paragraph = ParagraphBuilder(ParagraphStyle()).build();
 
-    PictureRecorder recorder = PictureRecorder();
-    Canvas recorderCanvas = Canvas(recorder);
-    Picture picture = recorder.endRecording();
-    Image image = picture.toImage(1, 1);
+    final PictureRecorder recorder = PictureRecorder();
+    final Canvas recorderCanvas = Canvas(recorder);
+    recorderCanvas.scale(1.0, 1.0);
+    final Picture picture = recorder.endRecording();
+    final Image image = picture.toImage(1, 1);
 
-    try { Canvas(null, null); } catch (error) { }
-    try { Canvas(null, rect); } catch (error) { }
-    try { Canvas(PictureRecorder(), null); } catch (error) { }
-    try { Canvas(PictureRecorder(), rect); } catch (error) { }
+    try { Canvas(null, null); } catch (error) { } // ignore: empty_catches
+    try { Canvas(null, rect); } catch (error) { } // ignore: empty_catches
+    try { Canvas(PictureRecorder(), null); } catch (error) { } // ignore: empty_catches
+    try { Canvas(PictureRecorder(), rect); } catch (error) { } // ignore: empty_catches
 
     try {
       PictureRecorder()
         ..endRecording()
         ..endRecording()
         ..endRecording();
-    } catch (error) { }
+    } catch (error) { } // ignore: empty_catches
 
     testCanvas((Canvas canvas) => canvas.clipPath(path));
     testCanvas((Canvas canvas) => canvas.clipRect(rect));
     testCanvas((Canvas canvas) => canvas.clipRRect(rrect));
     testCanvas((Canvas canvas) => canvas.drawArc(rect, 0.0, 0.0, false, paint));
-    testCanvas((Canvas canvas) => canvas.drawAtlas(image, [], [], [], BlendMode.src, rect, paint));
+    testCanvas((Canvas canvas) => canvas.drawAtlas(image, <RSTransform>[], <Rect>[], <Color>[], BlendMode.src, rect, paint));
     testCanvas((Canvas canvas) => canvas.drawCircle(offset, double.nan, paint));
     testCanvas((Canvas canvas) => canvas.drawColor(color, BlendMode.src));
     testCanvas((Canvas canvas) => canvas.drawDRRect(rrect, rrect, paint));
@@ -59,15 +60,15 @@ void main() {
     testCanvas((Canvas canvas) => canvas.drawParagraph(paragraph, offset));
     testCanvas((Canvas canvas) => canvas.drawPath(path, paint));
     testCanvas((Canvas canvas) => canvas.drawPicture(picture));
-    testCanvas((Canvas canvas) => canvas.drawPoints(PointMode.points, [], paint));
+    testCanvas((Canvas canvas) => canvas.drawPoints(PointMode.points, <Offset>[], paint));
     testCanvas((Canvas canvas) => canvas.drawRawAtlas(image, Float32List(0), Float32List(0), Int32List(0), BlendMode.src, rect, paint));
     testCanvas((Canvas canvas) => canvas.drawRawPoints(PointMode.points, Float32List(0), paint));
     testCanvas((Canvas canvas) => canvas.drawRect(rect, paint));
     testCanvas((Canvas canvas) => canvas.drawRRect(rrect, paint));
     testCanvas((Canvas canvas) => canvas.drawShadow(path, color, double.nan, null));
     testCanvas((Canvas canvas) => canvas.drawShadow(path, color, double.nan, false));
     testCanvas((Canvas canvas) => canvas.drawShadow(path, color, double.nan, true));
-    testCanvas((Canvas canvas) => canvas.drawVertices(Vertices(VertexMode.triangles, []), null, paint));
+    testCanvas((Canvas canvas) => canvas.drawVertices(Vertices(VertexMode.triangles, <Offset>[]), null, paint));
     testCanvas((Canvas canvas) => canvas.getSaveCount());
     testCanvas((Canvas canvas) => canvas.restore());
     testCanvas((Canvas canvas) => canvas.rotate(double.nan));