feat: enhance ScribanJsonHelper to support root array input and outpu…

SW.Bitween.Api/Resources/Mappers/Preview.cs

@@ -47,32 +47,40 @@ public async Task<MapperPreviewResponse> Handle(MapperPreviewRequest request)
         {
             var inputJson = request.InputJson;
 
-            JObject? jObj = null;
-            if (JToken.Parse(inputJson) is JObject parsedObj)
-                jObj = parsedObj;
+            var parsed = JToken.Parse(inputJson);
+            var jObj = parsed as JObject;
+            var jArr = parsed as JArray;
 
-            if (jObj != null)
-            {
-                var enriched = false;
+            JObject? partnerObj = partner?.AdapterProperties?.Count > 0
+                ? JObject.FromObject(partner.AdapterProperties)
+                : null;
 
-                if (partner?.AdapterProperties?.Count > 0)
-                {
-                    jObj["__partner__"] = JObject.FromObject(partner.AdapterProperties);
-                    enriched = true;
-                }
+            JObject? globalsObj = null;
+            var nonEmptySets = globalSets.Where(s => s.Values?.Count > 0).ToList();
+            if (nonEmptySets.Count > 0)
+            {
+                globalsObj = new JObject();
+                foreach (var set in nonEmptySets)
+                    globalsObj[set.Id] = JObject.FromObject(set.Values);
+            }
 
-                var nonEmptySets = globalSets.Where(s => s.Values?.Count > 0).ToList();
-                if (nonEmptySets.Count > 0)
+            if (jObj != null && (partnerObj != null || globalsObj != null))
+            {
+                if (partnerObj != null) jObj["__partner__"] = partnerObj;
+                if (globalsObj != null) jObj["__globals__"] = globalsObj;
+                inputJson = jObj.ToString(Formatting.None);
+            }
+            else if (jArr != null && (partnerObj != null || globalsObj != null))
+            {
+                foreach (var token in jArr)
                 {
-                    var globalsObj = new JObject();
-                    foreach (var set in nonEmptySets)
-                        globalsObj[set.Id] = JObject.FromObject(set.Values);
-                    jObj["__globals__"] = globalsObj;
-                    enriched = true;
+                    if (token is JObject elem)
+                    {
+                        if (partnerObj != null) elem["__partner__"] = partnerObj;
+                        if (globalsObj != null) elem["__globals__"] = globalsObj;
+                    }
                 }
-
-                if (enriched)
-                    inputJson = jObj.ToString(Formatting.None);
+                inputJson = jArr.ToString(Formatting.None);
             }
 
             var output = ScribanJsonHelper.Render(request.ScribanTemplate, inputJson);

SW.Bitween.NativeAdapters/JsonMapper/ScribanJsonHelper.cs

@@ -14,11 +14,37 @@ public static class ScribanJsonHelper
     /// </summary>`
     public static string Render(string scribanTemplate, string inputJson)
     {
-        // 1. Parse input JSON
-        var inputObj = JObject.Parse(inputJson);
+        // 1. Parse input JSON — handle both root object and root array
+        var rootToken = JToken.Parse(inputJson);
 
         // 2. Build top-level ScriptObject from input (recursive)
-        var scriptObj = BuildScriptObject(inputObj);
+        ScriptObject scriptObj;
+        if (rootToken is JArray rootArray)
+        {
+            // Expose the array under "items" and also forward member access to the
+            // first element so templates can write either:
+            //   {{ items[0].OrderId }}  or  {{ for item in items }} ... {{ end }}
+            scriptObj = new ScriptObject();
+            var smartArray = new SmartArray(rootArray.Select(ToScribanValue));
+            scriptObj["items"] = smartArray;
+
+            // If the first element is an object, also hoist its properties to the
+            // top level so templates that reference fields directly still work.
+            if (rootArray.Count > 0 && rootArray[0] is JObject firstObj)
+            {
+                var firstSo = BuildScriptObject(firstObj);
+                foreach (var key in firstSo.Keys.ToList())
+                    scriptObj.TrySetValue(null!, default, key, firstSo[key], false);
+            }
+        }
+        else if (rootToken is JObject rootObj)
+        {
+            scriptObj = BuildScriptObject(rootObj);
+        }
+        else
+        {
+            throw new InvalidOperationException("Input JSON must be a root object or root array.");
+        }
 
         // 3. Register custom functions (| json pipe, | to_float cast)
         var functions = new ScriptObject();
@@ -50,19 +76,19 @@ public static string Render(string scribanTemplate, string inputJson)
         // 6. Strip trailing commas that may appear after the last field/element
         rendered = Regex.Replace(rendered, @",(\s*[}\]])", "$1");
 
-        // 7. Parse rendered output as JToken
-        JObject flat;
+        // 7. Parse rendered output — root may be an object OR an array
+        JToken renderedToken;
         try
         {
-            flat = JObject.Parse(rendered);
+            renderedToken = JToken.Parse(rendered);
         }
         catch (JsonException ex)
         {
             throw new InvalidOperationException($"Template produced invalid JSON: {ex.Message}\n\nRendered:\n{rendered}");
         }
 
         // 8. Expand dotted keys into nested objects recursively at all depths
-        return ExpandDottedKeys(flat).ToString(Formatting.Indented);
+        return ExpandDottedKeys(renderedToken).ToString(Formatting.Indented);
     }
 
     // ─── Helpers ──────────────────────────────────────────────────────────────