Issue 21740. Allow inlining local variables declared in SwitchCase.

pkg/analysis_server/lib/src/services/refactoring/inline_local.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 services.src.refactoring.inline_local;
 
 import 'dart:async';
 
 import 'package:analysis_server/src/protocol_server.dart' hide Element;
 import 'package:analysis_server/src/services/correction/source_range.dart';
@@ skipping 61 matching lines @@
     {
       AstNode offsetNode = new NodeLocator.con1(offset).searchWithin(unit);
       if (offsetNode is SimpleIdentifier) {
         Element element = offsetNode.staticElement;
         if (element is LocalVariableElement) {
           _variableElement = element;
           _variableNode = element.node;
         }
       }
     }
-    if (_variableNode == null) {
+    // validate node declaration
+    if (!_isVariableDeclaredInStatement()) {
       result = new RefactoringStatus.fatal(
-          'Local variable declaration or reference must be selected to activate this refactoring.');
-      return new Future.value(result);
-    }
-    // should be normal variable declaration statement
-    if (_variableNode.parent is! VariableDeclarationList ||
-        _variableNode.parent.parent is! VariableDeclarationStatement ||
-        _variableNode.parent.parent.parent is! Block) {
-      result = new RefactoringStatus.fatal(
-          'Local variable declared in '
-              'statement should be selected to activate this refactoring.');
+          'Local variable declaration or reference must be selected '
+              'to activate this refactoring.');
       return new Future.value(result);
     }
     // should have initializer at declaration
     if (_variableNode.initializer == null) {
       String message = format(
           "Local variable '{0}' is not initialized at declaration.",
           _variableElement.displayName);
       result =
           new RefactoringStatus.fatal(message, newLocation_fromNode(_variableNode));
       return new Future.value(result);
@@ skipping 77 matching lines @@
           unitElement,
           newSourceEdit_range(range, codeForReference));
     }
     // done
     return new Future.value(change);
   }
 
   @override
   bool requiresPreview() => false;
 
+  bool _isVariableDeclaredInStatement() {
+    if (_variableNode == null) {
+      return false;
+    }
+    AstNode parent = _variableNode.parent;
+    if (parent is VariableDeclarationList) {
+      parent = parent.parent;
+      if (parent is VariableDeclarationStatement) {
+        parent = parent.parent;
+        return parent is Block || parent is SwitchCase;
+      }
+    }
+    return false;
+  }
+
   static bool _shouldBeExpressionInterpolation(InterpolationExpression target,
       Expression expression) {
     TokenType targetType = target.beginToken.type;
     return targetType == TokenType.STRING_INTERPOLATION_IDENTIFIER &&
         expression is! SimpleIdentifier;
   }
 
   static bool _shouldUseParenthesis(Expression init, AstNode node) {
     // check precedence
     int initPrecedence = getExpressionPrecedence(init);
     if (initPrecedence < getExpressionParentPrecedence(node)) {
       return true;
     }
     // special case for '-'
     AstNode parent = node.parent;
     if (init is PrefixExpression && parent is PrefixExpression) {
       if (parent.operator.type == TokenType.MINUS) {
         TokenType initializerOperator = init.operator.type;
         if (initializerOperator == TokenType.MINUS ||
             initializerOperator == TokenType.MINUS_MINUS) {
           return true;
         }
       }
     }
     // no () is needed
     return false;
   }
 }