Improve parser recovery on missing semicolon (issue 25846)

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/dart/element/element.dart';
@@ skipping 3998 matching lines @@
 
   void test_missingIdentifier_afterAnnotation() {
     MethodDeclaration method = parse3("parseClassMember", <Object>["C"],
         "@override }", [ParserErrorCode.EXPECTED_CLASS_MEMBER]);
     expect(method.documentationComment, isNull);
     NodeList<Annotation> metadata = method.metadata;
     expect(metadata, hasLength(1));
     expect(metadata[0].name.name, "override");
   }
 
+  void test_missingSemicolon_varialeDeclarationList() {
+    void verify(CompilationUnitMember member, String expectedTypeName,
+        String expectedName, String expectedSemicolon) {
+      expect(member, new isInstanceOf<TopLevelVariableDeclaration>());
+      TopLevelVariableDeclaration declaration = member;
+      VariableDeclarationList variableList = declaration.variables;
+      expect(variableList, isNotNull);
+      NodeList<VariableDeclaration> variables = variableList.variables;
+      expect(variables, hasLength(1));
+      VariableDeclaration variable = variables[0];
+      expect(variableList.type.toString(), expectedTypeName);
+      expect(variable.name.name, expectedName);
+      expect(declaration.semicolon.lexeme, expectedSemicolon);
+    }
+
+    CompilationUnit unit = ParserTestCase.parseCompilationUnit(
+        'String n x = "";', [
+      ParserErrorCode.EXPECTED_TOKEN,
+      ParserErrorCode.MISSING_CONST_FINAL_VAR_OR_TYPE
+    ]);
+    expect(unit, isNotNull);
+    NodeList<CompilationUnitMember> declarations = unit.declarations;
+    expect(declarations, hasLength(2));
+    verify(declarations[0], 'String', 'n', '');
+    verify(declarations[1], 'null', 'x', ';');
+  }
+
   void test_multiplicativeExpression_missing_LHS() {
     BinaryExpression expression =
         parseExpression("* y", [ParserErrorCode.MISSING_IDENTIFIER]);
     EngineTestCase.assertInstanceOf((obj) => obj is SimpleIdentifier,
         SimpleIdentifier, expression.leftOperand);
     expect(expression.leftOperand.isSynthetic, isTrue);
   }
 
   void test_multiplicativeExpression_missing_LHS_RHS() {
     BinaryExpression expression = parseExpression("*", [
@@ skipping 7563 matching lines @@
         new Scanner(null, new CharSequenceReader(source), listener);
     Token tokenStream = scanner.tokenize();
     //
     // Parse the source.
     //
     Parser parser = new Parser(null, listener);
     return invokeParserMethodImpl(
         parser, methodName, <Object>[tokenStream], tokenStream) as Token;
   }
 }