Write type parameters when writing members (issue 29714)

pkg/analyzer/lib/src/dart/element/member.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.src.dart.element.member;
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/constant/value.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/dart/element/type.dart';
@@ skipping 563 matching lines @@
 
   @override
   String toString() {
     MethodElement baseElement = this.baseElement;
     List<ParameterElement> parameters = this.parameters;
     FunctionType type = this.type;
     StringBuffer buffer = new StringBuffer();
     buffer.write(baseElement.enclosingElement.displayName);
     buffer.write(".");
     buffer.write(baseElement.displayName);
+    int typeParameterCount = typeParameters.length;
+    if (typeParameterCount > 0) {
+      buffer.write('<');
+      for (int i = 0; i < typeParameterCount; i++) {
+        if (i > 0) {
+          buffer.write(", ");
+        }
+        (typeParameters[i] as TypeParameterElementImpl).appendTo(buffer);
+      }
+      buffer.write('>');
+    }
     buffer.write("(");
+    String closing = null;
+    ParameterKind kind = ParameterKind.REQUIRED;
     int parameterCount = parameters.length;
     for (int i = 0; i < parameterCount; i++) {
       if (i > 0) {
         buffer.write(", ");
       }
-      buffer.write(parameters[i]);
+      ParameterElement parameter = parameters[i];
+      ParameterKind parameterKind = parameter.parameterKind;
+      if (parameterKind != kind) {
+        if (closing != null) {
+          buffer.write(closing);
+        }
+        if (parameterKind == ParameterKind.POSITIONAL) {
+          buffer.write("[");
+          closing = "]";
+        } else if (parameterKind == ParameterKind.NAMED) {
+          buffer.write("{");
+          closing = "}";
+        } else {
+          closing = null;
+        }
+      }
+      kind = parameterKind;
+      parameter.appendToWithoutDelimiters(buffer);
+    }
+    if (closing != null) {
+      buffer.write(closing);
     }
     buffer.write(")");
     if (type != null) {
       buffer.write(ElementImpl.RIGHT_ARROW);
       buffer.write(type.returnType);
     }
     return buffer.toString();
   }
 
   /**
@@ skipping 379 matching lines @@
   DartObject computeConstantValue() => baseElement.computeConstantValue();
 
   @override
   void visitChildren(ElementVisitor visitor) {
     // TODO(brianwilkerson) We need to finish implementing the accessors used
     // below so that we can safely invoke them.
     super.visitChildren(visitor);
     baseElement.initializer?.accept(visitor);
   }
 }