Add an interface for request parameters

pkg/analyzer_plugin/tool/spec/codegen_dart_protocol.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:convert';
 
 import 'package:analyzer/src/codegen/tools.dart';
 import 'package:html/dom.dart' as dom;
 
 import 'api.dart';
@@ skipping 205 matching lines @@
       });
       toHtmlVisitor.p(() {
         toHtmlVisitor.write(disclaimer);
       });
     }));
     write('class $className');
     if (impliedType.kind == 'refactoringFeedback') {
       writeln(' extends RefactoringFeedback implements HasToJson {');
     } else if (impliedType.kind == 'refactoringOptions') {
       writeln(' extends RefactoringOptions implements HasToJson {');
+    } else if (impliedType.kind == 'requestParams') {
+      writeln(' implements RequestParams {');
     } else if (impliedType.kind == 'requestResult') {
       writeln(' implements ResponseResult {');
     } else {
       writeln(' {');
     }
     indent(() {
-      if (impliedType.kind == 'requestResult') {
+      if (impliedType.kind == 'requestResult' ||
+          impliedType.kind == 'requestParams') {
         emitEmptyToJsonMember();
         writeln();
       }
       if (emitToRequestMember(impliedType)) {
         writeln();
       }
       if (emitToResponseMember(impliedType)) {
         writeln();
       }
       if (emitToNotificationMember(impliedType)) {
@@ skipping 155 matching lines @@
       }
       toHtmlVisitor.p(() {
         toHtmlVisitor.write(disclaimer);
       });
     }));
     write('class $className');
     if (impliedType.kind == 'refactoringFeedback') {
       writeln(' extends RefactoringFeedback {');
     } else if (impliedType.kind == 'refactoringOptions') {
       writeln(' extends RefactoringOptions {');
+    } else if (impliedType.kind == 'requestParams') {
+      writeln(' implements RequestParams {');
     } else if (impliedType.kind == 'requestResult') {
       writeln(' implements ResponseResult {');
     } else {
       writeln(' implements HasToJson {');
     }
     indent(() {
       if (emitSpecialStaticMembers(className)) {
         writeln();
       }
       for (TypeObjectField field in type.fields) {
@@ skipping 485 matching lines @@
     }
     return false;
   }
 
   /**
    * Emit the toRequest() code for a class, if appropriate.  Returns true if
    * code was emitted.
    */
   bool emitToRequestMember(ImpliedType impliedType) {
     if (impliedType.kind == 'requestParams') {
+      writeln('@override');
       writeln('Request toRequest(String id) {');
       indent(() {
         String methodString =
             literalString((impliedType.apiNode as Request).longMethod);
         String jsonPart = impliedType.type != null ? 'toJson()' : 'null';
         writeln('return new Request(id, $methodString, $jsonPart);');
       });
       writeln('}');
       return true;
     }
@@ skipping 344 matching lines @@
 
   @override
   String get asClosure => '($type value) => ${callback('value')}';
 
   @override
   bool get isIdentity => false;
 
   @override
   String asSnippet(String value) => callback(value);
 }