Add an integration test for kythe support with bug fixes

pkg/analyzer_plugin/lib/protocol/protocol_common.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.
 //
 // This file has been automatically generated.  Please do not edit it manually.
 // To regenerate the file, use the script
 // "pkg/analysis_server/tool/spec/generate_files".
 
 import 'dart:convert' hide JsonDecoder;
 
@@ skipping 2922 matching lines @@
   String toString() => "HighlightRegionType.$name";
 
   String toJson() => name;
 }
 
 /**
  * KytheEntry
  *
  * {
  *   "source": KytheVName
- *   "kind": String
- *   "target": KytheVName
+ *   "kind": optional String
+ *   "target": optional KytheVName
  *   "fact": String
- *   "value": List<int>
+ *   "value": optional List<int>
  * }
  *
  * Clients may not extend, implement or mix-in this class.
  */
 class KytheEntry implements HasToJson {
   KytheVName _source;
 
   String _kind;
 
   KytheVName _target;
 
   String _fact;
 
   List<int> _value;
 
   /**
-   * The ticket of the source node (must not be empty).
+   * The ticket of the source node.
    */
   KytheVName get source => _source;
 
   /**
-   * The ticket of the source node (must not be empty).
+   * The ticket of the source node.
    */
   void set source(KytheVName value) {
     assert(value != null);
     this._source = value;
   }
 
   /**
-   * An edge label (may be empty). The schema defines which labels are
-   * meaningful.
+   * An edge label. The schema defines which labels are meaningful.
    */
   String get kind => _kind;
 
   /**
-   * An edge label (may be empty). The schema defines which labels are
-   * meaningful.
+   * An edge label. The schema defines which labels are meaningful.
    */
   void set kind(String value) {
-    assert(value != null);
     this._kind = value;
   }
 
   /**
-   * The ticket of the target node (may be empty).
+   * The ticket of the target node.
    */
   KytheVName get target => _target;
 
   /**
-   * The ticket of the target node (may be empty).
+   * The ticket of the target node.
    */
   void set target(KytheVName value) {
-    assert(value != null);
     this._target = value;
   }
 
   /**
-   * A fact label (must not be empty). The schema defines which fact labels are
-   * meaningful.
+   * A fact label. The schema defines which fact labels are meaningful.
    */
   String get fact => _fact;
 
   /**
-   * A fact label (must not be empty). The schema defines which fact labels are
-   * meaningful.
+   * A fact label. The schema defines which fact labels are meaningful.
    */
   void set fact(String value) {
     assert(value != null);
     this._fact = value;
   }
 
   /**
-   * The String value of the fact (may be empty).
+   * The String value of the fact.
    */
   List<int> get value => _value;
 
   /**
-   * The String value of the fact (may be empty).
+   * The String value of the fact.
    */
   void set value(List<int> value) {
-    assert(value != null);
     this._value = value;
   }
 
-  KytheEntry(KytheVName source, String kind, KytheVName target, String fact,
-      List<int> value) {
+  KytheEntry(KytheVName source, String fact,
+      {String kind, KytheVName target, List<int> value}) {
     this.source = source;
     this.kind = kind;
     this.target = target;
     this.fact = fact;
     this.value = value;
   }
 
   factory KytheEntry.fromJson(
       JsonDecoder jsonDecoder, String jsonPath, Object json) {
     if (json == null) {
       json = {};
     }
     if (json is Map) {
       KytheVName source;
       if (json.containsKey("source")) {
         source = new KytheVName.fromJson(
             jsonDecoder, jsonPath + ".source", json["source"]);
       } else {
         throw jsonDecoder.mismatch(jsonPath, "source");
       }
       String kind;
       if (json.containsKey("kind")) {
         kind = jsonDecoder.decodeString(jsonPath + ".kind", json["kind"]);
-      } else {
-        throw jsonDecoder.mismatch(jsonPath, "kind");
       }
       KytheVName target;
       if (json.containsKey("target")) {
         target = new KytheVName.fromJson(
             jsonDecoder, jsonPath + ".target", json["target"]);
-      } else {
-        throw jsonDecoder.mismatch(jsonPath, "target");
       }
       String fact;
       if (json.containsKey("fact")) {
         fact = jsonDecoder.decodeString(jsonPath + ".fact", json["fact"]);
       } else {
         throw jsonDecoder.mismatch(jsonPath, "fact");
       }
       List<int> value;
       if (json.containsKey("value")) {
         value = jsonDecoder.decodeList(
             jsonPath + ".value", json["value"], jsonDecoder.decodeInt);
-      } else {
-        throw jsonDecoder.mismatch(jsonPath, "value");
       }
-      return new KytheEntry(source, kind, target, fact, value);
+      return new KytheEntry(source, fact,
+          kind: kind, target: target, value: value);
     } else {
       throw jsonDecoder.mismatch(jsonPath, "KytheEntry", json);
     }
   }
 
   @override
   Map<String, dynamic> toJson() {
     Map<String, dynamic> result = {};
     result["source"] = source.toJson();
-    result["kind"] = kind;
-    result["target"] = target.toJson();
+    if (kind != null) {
+      result["kind"] = kind;
+    }
+    if (target != null) {
+      result["target"] = target.toJson();
+    }
     result["fact"] = fact;
-    result["value"] = value;
+    if (value != null) {
+      result["value"] = value;
+    }
     return result;
   }
 
   @override
   String toString() => JSON.encode(toJson());
 
   @override
   bool operator ==(other) {
     if (other is KytheEntry) {
       return source == other.source &&
@@ skipping 2626 matching lines @@
 
   @override
   int get hashCode {
     int hash = 0;
     hash = JenkinsSmiHash.combine(hash, file.hashCode);
     hash = JenkinsSmiHash.combine(hash, fileStamp.hashCode);
     hash = JenkinsSmiHash.combine(hash, edits.hashCode);
     return JenkinsSmiHash.finish(hash);
   }
 }