Parse optional and named parameters.

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/element/element.dart';
 import 'package:analyzer/error/error.dart';
 import 'package:analyzer/src/generated/parser.dart' as analyzer;
 import 'package:analyzer/src/generated/utilities_dart.dart';
 import 'package:front_end/src/fasta/analyzer/ast_builder.dart';
@@ skipping 315 matching lines @@
   @override
   Expression parseExpression(String source,
       [List<ErrorCode> errorCodes = const <ErrorCode>[]]) {
     return _runParser(source, (parser) => parser.parseExpression, errorCodes)
         as Expression;
   }
 
   @override
   FormalParameter parseFormalParameter(String code, ParameterKind kind,
       {List<ErrorCode> errorCodes: const <ErrorCode>[]}) {
-    fasta.FormalParameterType type;
+    String parametersCode;
     if (kind == ParameterKind.REQUIRED) {
-      type = fasta.FormalParameterType.REQUIRED;
+      parametersCode = '($code)';
     } else if (kind == ParameterKind.POSITIONAL) {
-      type = fasta.FormalParameterType.POSITIONAL;
+      parametersCode = '([$code])';
     } else if (kind == ParameterKind.NAMED) {
-      type = fasta.FormalParameterType.NAMED;
+      parametersCode = '({$code})';
     } else {
       fail('$kind');
     }
-    return _runParser(
-        code,
-        (parser) => (token) => parser.parseFormalParameter(token, type),
-        errorCodes) as FormalParameter;
+    FormalParameterList list = parseFormalParameterList(parametersCode,
+        inFunctionType: false, errorCodes: errorCodes);
+    return list.parameters.single;
   }
 
   @override
   FormalParameterList parseFormalParameterList(String code,
       {bool inFunctionType: false,
       List<ErrorCode> errorCodes: const <ErrorCode>[]}) {
     return _runParser(
             code, (parser) => parser.parseFormalParameters, errorCodes)
         as FormalParameterList;
   }
@@ skipping 180 matching lines @@
 
   @override
   @failingTest
   void test_parseFormalParameter_type_function() {
     // TODO(scheglov): Unhandled event: FunctionTypedFormalParameter
     super.test_parseFormalParameter_type_function();
   }
 
   @override
   @failingTest
-  void test_parseFormalParameter_type_named() {
-    // TODO(scheglov): Unhandled event: ValuedFormalParameter
-    super.test_parseFormalParameter_type_named();
-  }
-
-  @override
-  @failingTest
-  void test_parseFormalParameter_type_positional() {
-    // TODO(scheglov): Unhandled event: ValuedFormalParameter
-    super.test_parseFormalParameter_type_positional();
-  }
-
-  @override
-  @failingTest
   void test_parseFormalParameter_var_named() {
     // TODO(scheglov): Unhandled event: ValuedFormalParameter
     super.test_parseFormalParameter_var_named();
   }
 
   @override
   @failingTest
   void test_parseFormalParameter_var_normal() {
     // TODO(scheglov): parse var
     super.test_parseFormalParameter_var_normal();
@@ skipping 765 matching lines @@
   void test_parseTypeAlias_genericFunction_typeParameters_voidReturnType() {
     super.test_parseTypeAlias_genericFunction_typeParameters_voidReturnType();
   }
 
   @override
   @failingTest
   void test_parseTypeAlias_genericFunction_voidReturnType() {
     super.test_parseTypeAlias_genericFunction_voidReturnType();
   }
 }