Always serialize conditions... even when empty

Author: mtdowling

smithy-rules-engine/src/main/java/software/amazon/smithy/rulesengine/language/syntax/rule/Rule.java

@@ -171,18 +171,17 @@ public Type typeCheck(Scope<Type> scope) {
     public Node toNode() {
         ObjectNode.Builder builder = ObjectNode.builder();
 
-        if (!conditions.isEmpty()) {
-            ArrayNode.Builder conditionsBuilder = ArrayNode.builder();
-            for (Condition condition : conditions) {
-                conditionsBuilder.withValue(condition.toNode());
-            }
-            builder.withMember(CONDITIONS, conditionsBuilder.build());
-        }
-
         if (documentation != null) {
             builder.withMember(DOCUMENTATION, documentation);
         }
 
+        // TODO: we should remove the requirement of serializing an empty array here
+        ArrayNode.Builder conditionsBuilder = ArrayNode.builder();
+        for (Condition condition : conditions) {
+            conditionsBuilder.withValue(condition.toNode());
+        }
+        builder.withMember(CONDITIONS, conditionsBuilder.build());
+
         withValueNode(builder);
         return builder.build();
     }

smithy-rules-engine/src/test/resources/software/amazon/smithy/rulesengine/language/minimal-ruleset.json

@@ -10,6 +10,7 @@
   "rules": [
     {
       "documentation": "base rule",
+      "conditions": [],
       "endpoint": {
         "url": "https://{Region}.amazonaws.com",
         "properties": {