Fix inference test annotation of named/optional parameters in function types.

pkg/analyzer/test/src/task/strong/front_end_inference_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 'dart:async';
 import 'dart:convert';
 import 'dart:io';
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/visitor.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/dart/element/type.dart';
 import 'package:analyzer/src/dart/analysis/driver.dart';
 import 'package:analyzer/src/generated/source.dart';
+import 'package:analyzer/src/generated/utilities_dart.dart';
 import 'package:front_end/src/base/instrumentation.dart' as fasta;
 import 'package:front_end/src/fasta/compiler_context.dart' as fasta;
 import 'package:front_end/src/fasta/testing/validating_instrumentation.dart'
     as fasta;
 import 'package:front_end/src/fasta/util/relativize.dart' show relativizeUri;
 import 'package:kernel/kernel.dart' as fasta;
 import 'package:path/path.dart' as pathos;
 import 'package:test/test.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
 
@@ skipping 180 matching lines @@
         buffer.write(separator);
       }
       writeItem(item);
       first = false;
     }
     buffer.write(close);
   }
 
   void _appendParameters(
       StringBuffer buffer, List<ParameterElement> parameters) {
-    _appendList<ParameterElement>(buffer, '(', ')', parameters, ', ',
-        (parameter) {
+    buffer.write('(');
+    bool first = true;
+    ParameterKind lastKind = ParameterKind.REQUIRED;
+    for (var parameter in parameters) {
+      if (!first) {
+        buffer.write(', ');
+      }
+      if (lastKind != parameter.parameterKind) {
+        if (parameter.parameterKind == ParameterKind.POSITIONAL) {
+          buffer.write('[');
+        } else if (parameter.parameterKind == ParameterKind.NAMED) {
+          buffer.write('{');
+        }
+      }
+      if (parameter.parameterKind == ParameterKind.NAMED) {
+        buffer.write(parameter.name);
+        buffer.write(': ');
+      }
       _appendType(buffer, parameter.type);
-    }, includeEmpty: true);
+      lastKind = parameter.parameterKind;
+      first = false;
+    }
+    if (lastKind == ParameterKind.POSITIONAL) {
+      buffer.write(']');
+    } else if (lastKind == ParameterKind.NAMED) {
+      buffer.write('}');
+    }
+    buffer.write(')');
   }
 
   void _appendType(StringBuffer buffer, DartType type) {
     if (type is FunctionType) {
       _appendTypeArguments(buffer, type.typeArguments);
       _appendParameters(buffer, type.parameters);
       buffer.write(' -> ');
       _appendType(buffer, type.returnType);
     } else if (type is InterfaceType) {
       ClassElement element = type.element;
@@ skipping 264 matching lines @@
 
   /// Based on DDC code generator's `_recoverTypeArguments`
   Iterable<DartType> _recoverTypeArguments(FunctionType g, FunctionType f) {
     assert(identical(g.element, f.element));
     assert(g.typeFormals.isNotEmpty && f.typeFormals.isEmpty);
     assert(g.typeFormals.length + g.typeArguments.length ==
         f.typeArguments.length);
     return f.typeArguments.skip(g.typeArguments.length);
   }
 }