Analyzer support for `@factory` methods (linter#253).

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 analyzer.src.generated.error;
 
 import 'dart:collection';
 
 import 'package:analyzer/dart/ast/ast.dart' show AstNode;
 import 'package:analyzer/dart/ast/token.dart';
@@ skipping 2664 matching lines @@
     CompileTimeErrorCode.YIELD_EACH_IN_NON_GENERATOR,
     CompileTimeErrorCode.YIELD_IN_NON_GENERATOR,
     HintCode.ARGUMENT_TYPE_NOT_ASSIGNABLE,
     HintCode.CAN_BE_NULL_AFTER_NULL_AWARE,
     HintCode.DEAD_CODE,
     HintCode.DEAD_CODE_CATCH_FOLLOWING_CATCH,
     HintCode.DEAD_CODE_ON_CATCH_SUBTYPE,
     HintCode.DEPRECATED_MEMBER_USE,
     HintCode.DUPLICATE_IMPORT,
     HintCode.DIVISION_OPTIMIZATION,
+    HintCode.INVALID_FACTORY_ANNOTATION,
+    HintCode.INVALID_FACTORY_METHOD_DECL,
+    HintCode.INVALID_FACTORY_METHOD_IMPL,
     HintCode.IS_DOUBLE,
     HintCode.IS_INT,
     HintCode.IS_NOT_DOUBLE,
     HintCode.IS_NOT_INT,
     HintCode.IMPORT_DEFERRED_LIBRARY_WITH_LOAD_FUNCTION,
     HintCode.INVALID_ASSIGNMENT,
     HintCode.INVALID_USE_OF_PROTECTED_MEMBER,
     HintCode.MISSING_JS_LIB_ANNOTATION,
     HintCode.MISSING_REQUIRED_PARAM,
     HintCode.MISSING_REQUIRED_PARAM_WITH_DETAILS,
@@ skipping 907 matching lines @@
    *
    * Parameters:
    * 0: the name of the right hand side type
    * 1: the name of the left hand side type
    */
   static const HintCode INVALID_ASSIGNMENT = const HintCode(
       'INVALID_ASSIGNMENT',
       "A value of type '{0}' cannot be assigned to a variable of type '{1}'");
 
   /**
+   * This hint is generated anywhere a @factory annotation is associated with
+   * anything other than a method.
+   */
+  static const HintCode INVALID_FACTORY_ANNOTATION = const HintCode(
+      'INVALID_FACTORY_ANNOTATION',
+      "Only methods can be annotated as factories.");
+
+  /**
+   * This hint is generated anywhere a @factory annotation is associated with
+   * a method that does not declare a return type.
+   */
+  static const HintCode INVALID_FACTORY_METHOD_DECL = const HintCode(
+      'INVALID_FACTORY_METHOD_DECL',
+      "Factory method '{0}' must have a return type.");
+
+  /**
+   * This hint is generated anywhere a @factory annotation is associated with
+   * a non-abstract method that can return anything other than a newly allocated
+   * object.
+   *
+   * Parameters:
+   * 0: the name of the method
+   */
+  static const HintCode INVALID_FACTORY_METHOD_IMPL = const HintCode(
+      'INVALID_FACTORY_METHOD_IMPL',
+      "Factory method '{0}' does not return a newly allocated object.");
+
+  /**
    * This hint is generated anywhere where a member annotated with `@protected`
    * is used outside an instance member of a subclass.
    *
    * Parameters:
    * 0: the name of the member
    * 1: the name of the defining class
    */
   static const HintCode INVALID_USE_OF_PROTECTED_MEMBER = const HintCode(
       'INVALID_USE_OF_PROTECTED_MEMBER',
       "The member '{0}' can only be used within instance members of subclasses of '{1}'");
@@ skipping 2343 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;
 }