New `whitespace_around_ops` lint (#249).

lib/src/rules.dart

 // Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library linter.src.rules;
 
 import 'dart:collection';
 
 import 'package:linter/src/config.dart';
 import 'package:linter/src/linter.dart';
@@ skipping 10 matching lines @@
 import 'package:linter/src/rules/close_sinks.dart';
 import 'package:linter/src/rules/comment_references.dart';
 import 'package:linter/src/rules/constant_identifier_names.dart';
 import 'package:linter/src/rules/control_flow_in_finally.dart';
 import 'package:linter/src/rules/empty_catches.dart';
 import 'package:linter/src/rules/empty_constructor_bodies.dart';
 import 'package:linter/src/rules/empty_statements.dart';
 import 'package:linter/src/rules/hash_and_equals.dart';
 import 'package:linter/src/rules/implementation_imports.dart';
 import 'package:linter/src/rules/iterable_contains_unrelated_type.dart';
-import 'package:linter/src/rules/list_remove_unrelated_type.dart';
 import 'package:linter/src/rules/library_names.dart';
 import 'package:linter/src/rules/library_prefixes.dart';
+import 'package:linter/src/rules/list_remove_unrelated_type.dart';
 import 'package:linter/src/rules/non_constant_identifier_names.dart';
 import 'package:linter/src/rules/one_member_abstracts.dart';
 import 'package:linter/src/rules/only_throw_errors.dart';
 import 'package:linter/src/rules/overridden_fields.dart';
 import 'package:linter/src/rules/package_api_docs.dart';
 import 'package:linter/src/rules/package_prefixed_library_names.dart';
 import 'package:linter/src/rules/prefer_is_not_empty.dart';
 import 'package:linter/src/rules/pub/package_names.dart';
 import 'package:linter/src/rules/public_member_api_docs.dart';
 import 'package:linter/src/rules/slash_for_doc_comments.dart';
 import 'package:linter/src/rules/sort_constructors_first.dart';
 import 'package:linter/src/rules/sort_unnamed_constructors_first.dart';
 import 'package:linter/src/rules/super_goes_last.dart';
 import 'package:linter/src/rules/test_types_in_equals.dart';
 import 'package:linter/src/rules/throw_in_finally.dart';
 import 'package:linter/src/rules/type_annotate_public_apis.dart';
 import 'package:linter/src/rules/type_init_formals.dart';
 import 'package:linter/src/rules/unawaited_futures.dart';
 import 'package:linter/src/rules/unnecessary_brace_in_string_interp.dart';
 import 'package:linter/src/rules/unnecessary_getters_setters.dart';
 import 'package:linter/src/rules/unrelated_type_equality_checks.dart';
+import 'package:linter/src/rules/whitespace_around_ops.dart';
 
 final Registry ruleRegistry = new Registry()
   ..register(new AlwaysDeclareReturnTypes())
   ..register(new AlwaysSpecifyTypes())
   ..register(new AnnotateOverrides())
   ..register(new AvoidAs())
   ..register(new AvoidEmptyElse())
   ..register(new AvoidReturnTypesOnSetters())
   ..register(new AvoidInitToNull())
   ..register(new AwaitOnlyFutures())
@@ skipping 27 matching lines @@
   ..register(new SortConstructorsFirst())
   ..register(new SortUnnamedConstructorsFirst())
   ..register(new SuperGoesLast())
   ..register(new TypeInitFormals())
   ..register(new TypeAnnotatePublicApis())
   ..register(new UnawaitedFutures())
   ..register(new UnnecessaryBraceInStringInterp())
   // Disabled pending fix: https://github.com/dart-lang/linter/issues/35
   //..register(new UnnecessaryGetters())
   ..register(new UnnecessaryGettersSetters())
-  ..register(new UnrelatedTypeEqualityChecks());
-
+  ..register(new UnrelatedTypeEqualityChecks())
+  ..register(new WhitespaceAroundOps());
 
 /// Registry of contributed lint rules.
 class Registry extends Object with IterableMixin<LintRule> {
   Map<String, LintRule> _ruleMap = <String, LintRule>{};
 
   @override
   Iterator<LintRule> get iterator => _ruleMap.values.iterator;
 
   Iterable<LintRule> get rules => _ruleMap.values;
 
   LintRule operator [](String key) => _ruleMap[key];
 
   /// All lint rules explicitly enabled by the given [config].
   ///
   /// For example:
   ///     my_rule: true
   ///
   /// enables `my_rule`.
   ///
   /// Unspecified rules are treated as disabled by default.
   Iterable<LintRule> enabled(LintConfig config) => rules
       .where((rule) => config.ruleConfigs.any((rc) => rc.enables(rule.name)));
 
   void register(LintRule rule) {
     _ruleMap[rule.name] = rule;
   }
 }