Add hint for use of ?. in conditions (issue 24649)

pkg/analyzer/lib/src/generated/error.dart

 // Copyright (c) 2014, 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 engine.error;
 
 import 'dart:collection';
 
 import 'package:source_span/source_span.dart';
 
@@ skipping 3005 matching lines @@
    *
    * Parameters:
    * 0: the name of the declared return type
    */
   static const HintCode MISSING_RETURN = const HintCode(
       'MISSING_RETURN',
       "This function declares a return type of '{0}', but does not end with a return statement",
       "Either add a return statement or change the return type to 'void'");
 
   /**
+   * Generate a hint for conditions in control flow statements that uses the

[pquitslund, 2015/10/28 04:40:35]

uses => use?

[Brian Wilkerson, 2015/10/28 15:27:38]

Actually, it needed a bigger re-write than that. But thanks for catching it.

+   * null-aware '?.' operator.
+   */
+  static const HintCode NULL_AWARE_IN_CONDITION = const HintCode(
+      'NULL_AWARE_IN_CONDITION',
+      "The value of the '?.' operator can be 'null', which is not appropriate in a condition",
+      "Replace the '?.' with a '.', testing the left-hand side for null if necessary");
+
+  /**
    * A getter with the override annotation does not override an existing getter.
    */
   static const HintCode OVERRIDE_ON_NON_OVERRIDING_GETTER = const HintCode(
       'OVERRIDE_ON_NON_OVERRIDING_GETTER',
       "Getter does not override an inherited getter");
 
   /**
    * A method with the override annotation does not override an existing method.
    */
   static const HintCode OVERRIDE_ON_NON_OVERRIDING_METHOD = const HintCode(
@@ skipping 2036 matching lines @@
    * Initialize a newly created error code to have the given [name].
    */
   const TodoCode(String name) : super(name, "{0}");
 
   @override
   ErrorSeverity get errorSeverity => ErrorSeverity.INFO;
 
   @override
   ErrorType get type => ErrorType.TODO;
 }