support class native clause

pkg/analyzer/test/generated/parser_fasta_test.dart

 // Copyright (c) 2017, 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.
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/token.dart' as analyzer;
+import 'package:analyzer/dart/ast/token.dart' show TokenType;
 import 'package:analyzer/error/error.dart';
 import 'package:analyzer/error/listener.dart' show ErrorReporter;
 import 'package:analyzer/src/dart/scanner/scanner.dart';
 import 'package:analyzer/src/fasta/ast_builder.dart';
 import 'package:analyzer/src/generated/parser.dart' as analyzer;
 import 'package:analyzer/src/generated/utilities_dart.dart';
 import 'package:analyzer/src/string_source.dart';
 import 'package:front_end/src/fasta/fasta_codes.dart' show Message;
 import 'package:front_end/src/fasta/kernel/kernel_builder.dart';
 import 'package:front_end/src/fasta/kernel/kernel_library_builder.dart';
@@ skipping 2909 matching lines @@
     super.test_parseTryStatement_on_catch_finally();
   }
 }
 
 /**
  * Tests of the fasta parser based on [TopLevelParserTestMixin].
  */
 @reflectiveTest
 class TopLevelParserTest_Fasta extends FastaParserTestCase
     with TopLevelParserTestMixin {
-  @override
-  @failingTest
-  void test_parseClassDeclaration_native() {
-    // TODO(paulberry): TODO(paulberry,ahe): Fasta parser doesn't appear to support "native" syntax yet.
-    super.test_parseClassDeclaration_native();
+  void test_parseClassDeclaration_native_missing_literal() {
+    createParser('class A native {}');
+    CompilationUnitMember member = parseFullCompilationUnitMember();
+    expect(member, isNotNull);
+    if (AstBuilder.isNativeClauseAllowed) {
+      assertNoErrors();
+    } else {
+      assertErrorsWithCodes([
+        ParserErrorCode.NATIVE_CLAUSE_SHOULD_BE_ANNOTATION,
+      ]);
+    }
+    expect(member, new isInstanceOf<ClassDeclaration>());
+    ClassDeclaration declaration = member;
+    expect(declaration.nativeClause, isNull);
+    expect(declaration.endToken.type, TokenType.CLOSE_CURLY_BRACKET);
+  }
+
+  void test_parseClassDeclaration_native_allowed() {
+    _setNativeAllowed(true, () {
+      test_parseClassDeclaration_native();
+    });
+  }
+
+  void test_parseClassDeclaration_native_missing_literal_allowed() {
+    _setNativeAllowed(true, () {
+      test_parseClassDeclaration_native_missing_literal();
+    });
+  }
+
+  void test_parseClassDeclaration_native_missing_literal_not_allowed() {
+    _setNativeAllowed(false, () {
+      test_parseClassDeclaration_native_missing_literal();
+    });
+  }
+
+  void test_parseClassDeclaration_native_not_allowed() {
+    _setNativeAllowed(false, () {
+      test_parseClassDeclaration_native();
+    });
   }
 
   @override
   @failingTest
   void test_parseCompilationUnit_builtIn_asFunctionName() {
     // TODO(paulberry,ahe): Fasta's parser is confused when one of the built-in
     // identifiers `export`, `import`, `library`, `part`, or `typedef` appears
     // as the name of a top level function with an implicit return type.
     super.test_parseCompilationUnit_builtIn_asFunctionName();
   }
@@ skipping 35 matching lines @@
     super.test_parseCompilationUnit_typedefAsPrefix();
     assertNoErrors();
   }
 
   @failingTest
   void test_parseCompilationUnitMember_abstractAsPrefix2() {
     // TODO(danrubel): should not be generating an error
     super.test_parseCompilationUnitMember_abstractAsPrefix();
     assertNoErrors();
   }
+
+  void _setNativeAllowed(bool isAllowed, Function f) {
+    bool original = AstBuilder.isNativeClauseAllowed;
+    AstBuilder.isNativeClauseAllowed = isAllowed;

[ahe, 2017/08/21 12:04:10]

You could make this an instance field on FastaParserTestCase. This way,
createParser can parse the boolean to ParserProxy.

[danrubel, 2017/08/22 01:35:28]

Good point. Revised.

+    try {
+      f();
+    } finally {
+      AstBuilder.isNativeClauseAllowed = original;
+    }
+  }
 }