refactor AstBuilder

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/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';
@@ skipping 449 matching lines @@
                   token,
                   inFunctionType
                       ? fasta.MemberKind.GeneralizedFunctionType
                       : fasta.MemberKind.NonStaticMethod);
             },
         errorCodes) as FormalParameterList;
   }
 
   @override
   CompilationUnitMember parseFullCompilationUnitMember() {
-    return _parserProxy.parseTopLevelDeclaration();
+    return _parserProxy.parseTopLevelDeclaration(false);
   }
 
   @override
   Directive parseFullDirective() {
-    return _parserProxy.parseTopLevelDeclaration();
+    return _parserProxy.parseTopLevelDeclaration(true);
   }
 
   @override
   FunctionExpression parseFunctionExpression(String code) {
     return _parseExpression(code);
   }
 
   @override
   InstanceCreationExpression parseInstanceCreationExpression(
       String code, analyzer.Token newToken) {
@@ skipping 345 matching lines @@
     return result;
   }
 
   @override
   CompilationUnit parseCompilationUnit2() {
     var result = _run((parser) => parser.parseUnit) as CompilationUnit;
     _eventListener.expectEmpty();
     return result;
   }
 
-  AnnotatedNode parseTopLevelDeclaration() {
+  AnnotatedNode parseTopLevelDeclaration(bool isDirective) {
     _eventListener.begin('CompilationUnit');
-    var result = _run((parser) => parser.parseTopLevelDeclaration);
+    _currentFastaToken =
+        _fastaParser.parseTopLevelDeclaration(_currentFastaToken);
+    expect(_currentFastaToken.isEof, isTrue);
+    expect(_astBuilder.stack, hasLength(0));
+    expect(_astBuilder.scriptTag, isNull);
+    expect(_astBuilder.directives, hasLength(isDirective ? 1 : 0));
+    expect(_astBuilder.declarations, hasLength(isDirective ? 0 : 1));
     _eventListener.end('CompilationUnit');
-    return result;
+    return (isDirective ? _astBuilder.directives : _astBuilder.declarations)
+        .first;
   }
 
   /**
    * Runs a single parser function, and returns the result as an analyzer AST.
    */
   Object _run(ParseFunction getParseFunction(fasta.Parser parser)) {
     var parseFunction = getParseFunction(_fastaParser);
     _currentFastaToken = parseFunction(_currentFastaToken);
     expect(_currentFastaToken.isEof, isTrue);
     expect(_astBuilder.stack, hasLength(1));
@@ skipping 168 matching lines @@
     assertNoErrors();
   }
 
   @failingTest
   void test_parseCompilationUnitMember_abstractAsPrefix2() {
     // TODO(danrubel): should not be generating an error
     super.test_parseCompilationUnitMember_abstractAsPrefix();
     assertNoErrors();
   }
 }