Cleanup based on new lints (#4052)

.analysis_options

 # Specify analysis options.
-#
-# Note that until there is a default "all-in" lint rule-set we need
-# to opt-in to all desired lints (https://github.com/dart-lang/sdk/issues/25843).
-# For a list of lints, see: http://dart-lang.github.io/linter/lints/
 
 # This file is the .analysis_options file used by Flutter editors, such as
 # Atom. It is very similar to flutter_tools/flutter_analysis_options; the only
@@ -23,33 +19,52 @@ analyzer:
     strong_mode_down_cast_composite: ignore
     # we allow having TODOs in the code
     todo: ignore
+
 linter:
   rules:
+    # these are in the same order as http://dart-lang.github.io/linter/lints/
+    # to make maintenance easier
+
+    # error rules
     - avoid_empty_else
+    # - comment_references
+    - control_flow_in_finally
+    - hash_and_equals
+    # - iterable_contains_unrelated_type
+    - test_types_in_equals
+    - throw_in_finally
+    - unrelated_type_equality_checks
+
+    # style rules
     - always_declare_return_types
     - always_specify_types
     - annotate_overrides
     - avoid_as
     - avoid_init_to_null
-    # - avoid_return_types_on_setters # https://github.com/dart-lang/linter/issues/202
+    - avoid_return_types_on_setters
+    - await_only_futures
     - camel_case_types
-    # - constant_identifier_names # https://github.com/dart-lang/linter/issues/204 (and 203)
+    # - constant_identifier_names
+    - control_flow_in_finally
     - empty_constructor_bodies
-    - hash_and_equals
-    # - implementation_imports # https://github.com/dart-lang/linter/issues/203
+    - implementation_imports
     - library_names
     - library_prefixes
     - non_constant_identifier_names
-    # - one_member_abstracts # https://github.com/dart-lang/linter/issues/203
+    - one_member_abstracts
+    # - overriden_field
     - package_api_docs
-    - package_names
     - package_prefixed_library_names
     - prefer_is_not_empty
+    # - public_member_api_docs
     - slash_for_doc_comments
     - sort_constructors_first
     - sort_unnamed_constructors_first
     - super_goes_last
-    - type_annotate_public_apis # subset of always_specify_types
+    # - type_annotate_public_apis # subset of always_specify_types
     - type_init_formals
     - unnecessary_brace_in_string_interp
     - unnecessary_getters_setters
+
+    # pub rules
+    - package_names

packages/flutter/lib/src/foundation/assertions.dart

@@ -290,7 +290,7 @@ class FlutterError extends AssertionError {
       }
       result.add(line);
     }
-    if (skipped == 1) {
+    if (skipped.length == 1) {
       result.add('(elided one frame from ${skipped.single})');
     } else if (skipped.length > 1) {
       List<String> where = new Set<String>.from(skipped).toList()..sort();

packages/flutter/lib/src/rendering/box.dart

@@ -963,6 +963,11 @@ abstract class RenderBox extends RenderObject {
 
   int _debugActivePointers = 0;
 
+  /// Override this function to handle pointer events that hit this render object.
+  ///
+  /// For [RenderBox] objects, the `entry` argument is a [BoxHitTestEntry]. From this
+  /// object you can determine the [PointerDownEvent]'s position in local coordinates.
+  /// (This is useful because [PointerEvent.position] is in global coordinates.)
   @override
   void handleEvent(PointerEvent event, HitTestEntry entry) {
     super.handleEvent(event, entry);

packages/flutter/lib/src/widgets/focus.dart

@@ -130,8 +130,13 @@ class Focus extends StatefulWidget {
       if (debugOnlyFocusedKey?.currentContext == null)
         debugOnlyFocusedKey = context.widget.key;
       if (debugOnlyFocusedKey != context.widget.key) {
-        debugPrint('Tried to focus widgets with two different keys: $debugOnlyFocusedKey and ${context.widget.key}');
-        assert('If you have more than one focusable widget, then you should put them inside a Focus.' == true);
+        throw new FlutterError(
+          'Missing Focus scope.\n'
+          'Two focusable widgets with different keys, $debugOnlyFocusedKey and ${context.widget.key}, '
+          'exist in the widget tree simultaneously, but they have no Focus widget ancestor.\n'
+          'If you have more than one focusable widget, then you should put them inside a Focus. '
+          'Normally, this is done for you using a Route, via Navigator, WidgetsApp, or MaterialApp.'
+        );
       }
       return true;
     });

packages/flutter/test/widget/lazy_block_viewport_test.dart

@@ -183,7 +183,7 @@ void main() {
 
     expect(callbackTracker, equals(<int>[0, 1, 2]));
     callbackTracker.clear();
-    await tester.allWidgets.forEach(collectText);
+    tester.allWidgets.forEach(collectText);
     expect(text, equals(<String>['0', '1', '2']));
     text.clear();
 
@@ -191,7 +191,7 @@ void main() {
 
     expect(callbackTracker, equals(<int>[0, 1, 2]));
     callbackTracker.clear();
-    await tester.allWidgets.forEach(collectText);
+    tester.allWidgets.forEach(collectText);
     expect(text, equals(<String>['0', '1', '2']));
     text.clear();
   });

packages/flutter_tools/flutter_analysis_options

@@ -3,11 +3,13 @@
 # Note that until there is a default "all-in" lint rule-set we need
 # to opt-in to all desired lints (https://github.com/dart-lang/sdk/issues/25843).
 # For a list of lints, see: http://dart-lang.github.io/linter/lints/
-
+#
 # This file is the .analysis_options file used by "flutter analyze".
 # It isn't named that because otherwise editors like Atom would try
 # to use it, and that wouldn't work because it enables things that
 # need to be silenced, in particular, public_member_api_docs.
+#
+# When editing, make sure you keep /.analysis_options consistent.
 
 analyzer:
   language:
@@ -23,26 +25,41 @@ analyzer:
     strong_mode_down_cast_composite: ignore
     # we allow having TODOs in the code
     todo: ignore
+
 linter:
   rules:
+    # these are in the same order as http://dart-lang.github.io/linter/lints/
+    # to make maintenance easier
+
+    # # error rules
     - avoid_empty_else
+    # - comment_references # blocked on https://github.com/dart-lang/dartdoc/issues/1153
+    - control_flow_in_finally
+    - hash_and_equals
+    # - iterable_contains_unrelated_type # https://github.com/dart-lang/linter/issues/245
+    - test_types_in_equals
+    - throw_in_finally
+    - unrelated_type_equality_checks
+
+    # style rules
     - always_declare_return_types
     - always_specify_types
     - annotate_overrides
     - avoid_as
     - avoid_init_to_null
     - avoid_return_types_on_setters
+    - await_only_futures
     - camel_case_types
-    # - constant_identifier_names # https://github.com/dart-lang/linter/issues/204 (and 203)
+    # - constant_identifier_names # https://github.com/dart-lang/linter/issues/204
+    - control_flow_in_finally
     - empty_constructor_bodies
-    - hash_and_equals
     - implementation_imports
     - library_names
     - library_prefixes
     - non_constant_identifier_names
     - one_member_abstracts
+    # - overriden_field # the analyzer code itself violates this right now :-)
     - package_api_docs
-    - package_names
     - package_prefixed_library_names
     - prefer_is_not_empty
     - public_member_api_docs
@@ -50,6 +67,10 @@ linter:
     - sort_constructors_first
     - sort_unnamed_constructors_first
     - super_goes_last
+    # - type_annotate_public_apis # subset of always_specify_types
     - type_init_formals
     - unnecessary_brace_in_string_interp
     - unnecessary_getters_setters
+
+    # pub rules
+    - package_names

packages/flutter_tools/lib/executable.dart

@@ -91,8 +91,10 @@ Future<Null> main(List<String> args) async {
     if (error is UsageException) {
       stderr.writeln(error.message);
       stderr.writeln();
-      stderr.writeln("Run 'flutter -h' (or 'flutter <command> -h') for available "
-        "flutter commands and options.");
+      stderr.writeln(
+        "Run 'flutter -h' (or 'flutter <command> -h') for available "
+        "flutter commands and options."
+      );
       // Argument error exit code.
       _exit(64);
     } else if (error is ProcessExit) {
@@ -118,7 +120,8 @@ Future<Null> main(List<String> args) async {
 
         stderr.writeln(
           'Crash report written to ${file.path};\n'
-          'please let us know at https://github.com/flutter/flutter/issues.');
+          'please let us know at https://github.com/flutter/flutter/issues.'
+        );
       }
 
       _exit(1);
@@ -129,21 +132,21 @@ Future<Null> main(List<String> args) async {
 File _createCrashReport(List<String> args, dynamic error, Chain chain) {
   File crashFile = getUniqueFile(Directory.current, 'flutter', 'log');
 
-  StringBuffer buf = new StringBuffer();
+  StringBuffer buffer = new StringBuffer();
 
-  buf.writeln('Flutter crash report; please file at https://github.com/flutter/flutter/issues.\n');
+  buffer.writeln('Flutter crash report; please file at https://github.com/flutter/flutter/issues.\n');
 
-  buf.writeln('## command\n');
-  buf.writeln('flutter ${args.join(' ')}\n');
+  buffer.writeln('## command\n');
+  buffer.writeln('flutter ${args.join(' ')}\n');
 
-  buf.writeln('## exception\n');
-  buf.writeln('$error\n');
-  buf.writeln('```\n${chain.terse}```\n');
+  buffer.writeln('## exception\n');
+  buffer.writeln('$error\n');
+  buffer.writeln('```\n${chain.terse}```\n');
 
-  buf.writeln('## flutter doctor\n');
-  buf.writeln('```\n${_doctorText()}```');
+  buffer.writeln('## flutter doctor\n');
+  buffer.writeln('```\n${_doctorText()}```');
 
-  crashFile.writeAsStringSync(buf.toString());
+  crashFile.writeAsStringSync(buffer.toString());
 
   return crashFile;
 }
@@ -179,7 +182,7 @@ Future<Null> _exit(int code) async {
   logger.flush();
 
   // Give the task / timer queue one cycle through before we hard exit.
-  await Timer.run(() {
+  Timer.run(() {
     printTrace('exiting with code $code');
     exit(code);
   });

packages/flutter_tools/lib/src/commands/drive.dart

@@ -261,7 +261,7 @@ Future<int> startApp(DriveCommand command, BuildMode buildMode) async {
   printTrace('Installing application package.');
   ApplicationPackage package = command.applicationPackages
       .getPackageForPlatform(command.device.platform);
-  await command.device.installApp(package);
+  command.device.installApp(package);
 
   printTrace('Starting application.');
   LaunchResult result = await command.device.startApp(

packages/flutter_tools/lib/src/commands/run.dart

@@ -205,7 +205,7 @@ Future<int> startApp(
   if (install && device is AndroidDevice) {
     printStatus('Installing $package to $device...');
 
-    if (!(await installApp(device, package)))
+    if (!(installApp(device, package)))
       return 1;
   }
 
@@ -345,7 +345,7 @@ class _RunAndStayResident {
     // TODO(devoncarew): This fails for ios devices - we haven't built yet.
     if (device is AndroidDevice) {
       printTrace('Running install command.');
-      if (!(await installApp(device, package)))
+      if (!(installApp(device, package)))
         return 1;
     }
 

packages/flutter_tools/lib/src/ios/simulators.dart

@@ -78,7 +78,7 @@ class SimControl {
     bool connected = false;
     int attempted = 0;
     while (!connected && attempted < 20) {
-      connected = await _isAnyConnected();
+      connected = _isAnyConnected();
       if (!connected) {
         printStatus('Still waiting for iOS Simulator to boot...');
         await new Future<Null>.delayed(new Duration(seconds: 1));

packages/flx/test/bundle_test.dart

@@ -24,7 +24,7 @@ Future<Null> main() async {
   final Uint8List kTestBytes = new Uint8List.fromList(<int>[1, 2, 3]);
 
   // Create a temp dir and file for the bundle.
-  Directory tempDir = await Directory.systemTemp.createTempSync('bundle_test');
+  Directory tempDir = Directory.systemTemp.createTempSync('bundle_test');
   String bundlePath = tempDir.path + '/bundle.flx';
 
   AsymmetricKeyPair<PublicKey, PrivateKey> keyPair = keyPairFromPrivateKeyBytes(kPrivateKeyDER);