Remove special list behavior in analysis server protocol.

pkg/analysis_server/lib/src/generated_protocol.dart

Index: pkg/analysis_server/lib/src/generated_protocol.dart
diff --git a/pkg/analysis_server/lib/src/generated_protocol.dart b/pkg/analysis_server/lib/src/generated_protocol.dart
index 6a4a19d8ae56a90f1876f40ef1100f27c3224913..e8fc6ddb51186bccceedcc6c68bead12cae4c93e 100644
--- a/pkg/analysis_server/lib/src/generated_protocol.dart
+++ b/pkg/analysis_server/lib/src/generated_protocol.dart
@@ -2798,11 +2798,7 @@ class SearchGetTypeHierarchyResult implements HasToJson {
    */
   List<TypeHierarchyItem> hierarchyItems;
 
-  SearchGetTypeHierarchyResult({this.hierarchyItems}) {
-    if (hierarchyItems == null) {
-      hierarchyItems = <TypeHierarchyItem>[];
-    }
-  }
+  SearchGetTypeHierarchyResult({this.hierarchyItems});
 
   factory SearchGetTypeHierarchyResult.fromJson(JsonDecoder jsonDecoder, String jsonPath, Object json) {
     if (json == null) {
@@ -2812,8 +2808,6 @@ class SearchGetTypeHierarchyResult implements HasToJson {
       List<TypeHierarchyItem> hierarchyItems;
       if (json.containsKey("hierarchyItems")) {
         hierarchyItems = jsonDecoder._decodeList(jsonPath + ".hierarchyItems", json["hierarchyItems"], (String jsonPath, Object json) => new TypeHierarchyItem.fromJson(jsonDecoder, jsonPath, json));
-      } else {
-        hierarchyItems = <TypeHierarchyItem>[];
       }
       return new SearchGetTypeHierarchyResult(hierarchyItems: hierarchyItems);
     } else {
@@ -2828,7 +2822,7 @@ class SearchGetTypeHierarchyResult implements HasToJson {
 
   Map<String, dynamic> toJson() {
     Map<String, dynamic> result = {};
-    if (hierarchyItems.isNotEmpty) {
+    if (hierarchyItems != null) {
       result["hierarchyItems"] = hierarchyItems.map((TypeHierarchyItem value) => value.toJson()).toList();
     }
     return result;
@@ -3633,11 +3627,7 @@ class EditGetRefactoringResult implements HasToJson {
    */
   List<String> potentialEdits;
 
-  EditGetRefactoringResult(this.initialProblems, this.optionsProblems, this.finalProblems, {this.feedback, this.change, this.potentialEdits}) {
-    if (potentialEdits == null) {
-      potentialEdits = <String>[];
-    }
-  }
+  EditGetRefactoringResult(this.initialProblems, this.optionsProblems, this.finalProblems, {this.feedback, this.change, this.potentialEdits});
 
   factory EditGetRefactoringResult.fromJson(JsonDecoder jsonDecoder, String jsonPath, Object json) {
     if (json == null) {
@@ -3673,8 +3663,6 @@ class EditGetRefactoringResult implements HasToJson {
       List<String> potentialEdits;
       if (json.containsKey("potentialEdits")) {
         potentialEdits = jsonDecoder._decodeList(jsonPath + ".potentialEdits", json["potentialEdits"], jsonDecoder._decodeString);
-      } else {
-        potentialEdits = <String>[];
       }
       return new EditGetRefactoringResult(initialProblems, optionsProblems, finalProblems, feedback: feedback, change: change, potentialEdits: potentialEdits);
     } else {
@@ -3698,7 +3686,7 @@ class EditGetRefactoringResult implements HasToJson {
     if (change != null) {
       result["change"] = change.toJson();
     }
-    if (potentialEdits.isNotEmpty) {
+    if (potentialEdits != null) {
       result["potentialEdits"] = potentialEdits;
     }
     return result;
@@ -4383,11 +4371,7 @@ class ExecutionLaunchDataParams implements HasToJson {
    */
   List<String> referencedFiles;
 
-  ExecutionLaunchDataParams(this.file, {this.kind, this.referencedFiles}) {
-    if (referencedFiles == null) {
-      referencedFiles = <String>[];
-    }
-  }
+  ExecutionLaunchDataParams(this.file, {this.kind, this.referencedFiles});
 
   factory ExecutionLaunchDataParams.fromJson(JsonDecoder jsonDecoder, String jsonPath, Object json) {
     if (json == null) {
@@ -4407,8 +4391,6 @@ class ExecutionLaunchDataParams implements HasToJson {
       List<String> referencedFiles;
       if (json.containsKey("referencedFiles")) {
         referencedFiles = jsonDecoder._decodeList(jsonPath + ".referencedFiles", json["referencedFiles"], jsonDecoder._decodeString);
-      } else {
-        referencedFiles = <String>[];
       }
       return new ExecutionLaunchDataParams(file, kind: kind, referencedFiles: referencedFiles);
     } else {
@@ -4427,7 +4409,7 @@ class ExecutionLaunchDataParams implements HasToJson {
     if (kind != null) {
       result["kind"] = kind.toJson();
     }
-    if (referencedFiles.isNotEmpty) {
+    if (referencedFiles != null) {
       result["referencedFiles"] = referencedFiles;
     }
     return result;
@@ -5365,14 +5347,7 @@ class CompletionSuggestion implements HasToJson {
    */
   String parameterType;
 
-  CompletionSuggestion(this.kind, this.relevance, this.completion, this.selectionOffset, this.selectionLength, this.isDeprecated, this.isPotential, {this.docSummary, this.docComplete, this.declaringType, this.element, this.returnType, this.parameterNames, this.parameterTypes, this.requiredParameterCount, this.positionalParameterCount, this.parameterName, this.parameterType}) {
-    if (parameterNames == null) {
-      parameterNames = <String>[];
-    }
-    if (parameterTypes == null) {
-      parameterTypes = <String>[];
-    }
-  }
+  CompletionSuggestion(this.kind, this.relevance, this.completion, this.selectionOffset, this.selectionLength, this.isDeprecated, this.isPotential, {this.docSummary, this.docComplete, this.declaringType, this.element, this.returnType, this.parameterNames, this.parameterTypes, this.requiredParameterCount, this.positionalParameterCount, this.parameterName, this.parameterType});
 
   factory CompletionSuggestion.fromJson(JsonDecoder jsonDecoder, String jsonPath, Object json) {
     if (json == null) {
@@ -5444,14 +5419,10 @@ class CompletionSuggestion implements HasToJson {
       List<String> parameterNames;
       if (json.containsKey("parameterNames")) {
         parameterNames = jsonDecoder._decodeList(jsonPath + ".parameterNames", json["parameterNames"], jsonDecoder._decodeString);
-      } else {
-        parameterNames = <String>[];
       }
       List<String> parameterTypes;
       if (json.containsKey("parameterTypes")) {
         parameterTypes = jsonDecoder._decodeList(jsonPath + ".parameterTypes", json["parameterTypes"], jsonDecoder._decodeString);
-      } else {
-        parameterTypes = <String>[];
       }
       int requiredParameterCount;
       if (json.containsKey("requiredParameterCount")) {
@@ -5499,10 +5470,10 @@ class CompletionSuggestion implements HasToJson {
     if (returnType != null) {
       result["returnType"] = returnType;
     }
-    if (parameterNames.isNotEmpty) {
+    if (parameterNames != null) {
       result["parameterNames"] = parameterNames;
     }
-    if (parameterTypes.isNotEmpty) {
+    if (parameterTypes != null) {
       result["parameterTypes"] = parameterTypes;
     }
     if (requiredParameterCount != null) {
@@ -7442,11 +7413,7 @@ class Outline implements HasToJson {
    */
   List<Outline> children;
 
-  Outline(this.element, this.offset, this.length, {this.children}) {
-    if (children == null) {
-      children = <Outline>[];
-    }
-  }
+  Outline(this.element, this.offset, this.length, {this.children});
 
   factory Outline.fromJson(JsonDecoder jsonDecoder, String jsonPath, Object json) {
     if (json == null) {
@@ -7474,8 +7441,6 @@ class Outline implements HasToJson {
       List<Outline> children;
       if (json.containsKey("children")) {
         children = jsonDecoder._decodeList(jsonPath + ".children", json["children"], (String jsonPath, Object json) => new Outline.fromJson(jsonDecoder, jsonPath, json));
-      } else {
-        children = <Outline>[];
       }
       return new Outline(element, offset, length, children: children);
     } else {
@@ -7488,7 +7453,7 @@ class Outline implements HasToJson {
     result["element"] = element.toJson();
     result["offset"] = offset;
     result["length"] = length;
-    if (children.isNotEmpty) {
+    if (children != null) {
       result["children"] = children.map((Outline value) => value.toJson()).toList();
     }
     return result;
@@ -7554,11 +7519,7 @@ class Override implements HasToJson {
    */
   List<OverriddenMember> interfaceMembers;
 
-  Override(this.offset, this.length, {this.superclassMember, this.interfaceMembers}) {
-    if (interfaceMembers == null) {
-      interfaceMembers = <OverriddenMember>[];
-    }
-  }
+  Override(this.offset, this.length, {this.superclassMember, this.interfaceMembers});
 
   factory Override.fromJson(JsonDecoder jsonDecoder, String jsonPath, Object json) {
     if (json == null) {
@@ -7584,8 +7545,6 @@ class Override implements HasToJson {
       List<OverriddenMember> interfaceMembers;
       if (json.containsKey("interfaceMembers")) {
         interfaceMembers = jsonDecoder._decodeList(jsonPath + ".interfaceMembers", json["interfaceMembers"], (String jsonPath, Object json) => new OverriddenMember.fromJson(jsonDecoder, jsonPath, json));
-      } else {
-        interfaceMembers = <OverriddenMember>[];
       }
       return new Override(offset, length, superclassMember: superclassMember, interfaceMembers: interfaceMembers);
     } else {
@@ -7600,7 +7559,7 @@ class Override implements HasToJson {
     if (superclassMember != null) {
       result["superclassMember"] = superclassMember.toJson();
     }
-    if (interfaceMembers.isNotEmpty) {
+    if (interfaceMembers != null) {
       result["interfaceMembers"] = interfaceMembers.map((OverriddenMember value) => value.toJson()).toList();
     }
     return result;