Fix for issue 4070

pkg/analyzer/test/generated/parser_test.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.parser_test;
 
 import 'package:analyzer/src/generated/ast.dart';
 import 'package:analyzer/src/generated/element.dart';
 import 'package:analyzer/src/generated/error.dart';
 import 'package:analyzer/src/generated/incremental_scanner.dart';
@@ skipping 2342 matching lines @@
         "(a, b])",
         [ParserErrorCode.UNEXPECTED_TERMINATOR_FOR_PARAMETER_GROUP]);
   }
 
   void test_unexpectedToken_endOfFieldDeclarationStatement() {
     ParserTestCase.parseStatement(
         "String s = (null));",
         [ParserErrorCode.UNEXPECTED_TOKEN]);
   }
 
+  void test_unexpectedToken_returnInExpressionFuntionBody() {
+    ParserTestCase.parseCompilationUnit(
+        "f() => return null;",
+        [ParserErrorCode.UNEXPECTED_TOKEN]);
+  }
+
   void test_unexpectedToken_semicolonBetweenClassMembers() {
     ParserTestCase.parse3(
         "parseClassDeclaration",
         <Object>[emptyCommentAndMetadata(), null],
         "class C { int x; ; int y;}",
         [ParserErrorCode.UNEXPECTED_TOKEN]);
   }
 
   void test_unexpectedToken_semicolonBetweenCompilationUnitMembers() {
     ParserTestCase.parseCompilationUnit(
@@ skipping 8571 matching lines @@
     // Parse the source.
     //
     Parser parser = new Parser(null, listener);
     return invokeParserMethodImpl(
         parser,
         methodName,
         <Object>[tokenStream],
         tokenStream) as Token;
   }
 }