Improve error recovery (issue 27646)

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 analyzer.test.generated.parser_test;
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/token.dart';
 import 'package:analyzer/dart/ast/visitor.dart';
 import 'package:analyzer/error/error.dart';
@@ skipping 3105 matching lines @@
 
   void test_additiveExpression_super() {
     BinaryExpression expression = parseExpression("super + +", [
       ParserErrorCode.MISSING_IDENTIFIER,
       ParserErrorCode.MISSING_IDENTIFIER
     ]);
     EngineTestCase.assertInstanceOf((obj) => obj is BinaryExpression,
         BinaryExpression, expression.leftOperand);
   }
 
+  void test_assignableSelector() {
+    IndexExpression expression =
+        parseExpression("a.b[]", [ParserErrorCode.MISSING_IDENTIFIER]);
+    Expression index = expression.index;
+    expect(index, new isInstanceOf<SimpleIdentifier>());
+    expect(index.isSynthetic, isTrue);
+  }
+
   void test_assignmentExpression_missing_compound1() {
     AssignmentExpression expression =
         parseExpression("= y = 0", [ParserErrorCode.MISSING_IDENTIFIER]);
     Expression syntheticExpression = expression.leftHandSide;
     EngineTestCase.assertInstanceOf((obj) => obj is SimpleIdentifier,
         SimpleIdentifier, syntheticExpression);
     expect(syntheticExpression.isSynthetic, isTrue);
   }
 
   void test_assignmentExpression_missing_compound2() {
@@ skipping 10315 matching lines @@
   CompilationUnit _parseDirectives(String source,
       [List<ErrorCode> errorCodes = ErrorCode.EMPTY_LIST]) {
     createParser(source);
     CompilationUnit unit = parser.parseDirectives2();
     expect(unit, isNotNull);
     expect(unit.declarations, hasLength(0));
     listener.assertErrorsWithCodes(errorCodes);
     return unit;
   }
 }