Merge pull request #91 from tgiachi/develop

feat(scripting-lua): marshal dictionary and list returns to Lua tables

Author: tgiachi

src/SquidStd.Scripting.Lua/Services/LuaScriptEngineService.cs

@@ -1,3 +1,4 @@
+using System.Collections;
 using System.Collections.Concurrent;
 using System.Diagnostics;
 using System.Diagnostics.CodeAnalysis;
@@ -697,7 +698,50 @@ private void AttachLuaEventBridge()
         };
 
     private DynValue ConvertToLua(object? value)
-        => value == null ? DynValue.Nil : DynValue.FromObject(LuaScript, value);
+    {
+        switch (value)
+        {
+            case null:
+                return DynValue.Nil;
+
+            case DynValue dynValue:
+                return dynValue;
+
+            case string:
+                return DynValue.FromObject(LuaScript, value);
+
+            case IDictionary dictionary:
+            {
+                var table = new Table(LuaScript);
+
+                foreach (DictionaryEntry entry in dictionary)
+                {
+                    table[ConvertKey(entry.Key)] = ConvertToLua(entry.Value);
+                }
+
+                return DynValue.NewTable(table);
+            }
+
+            case IEnumerable enumerable:
+            {
+                var table = new Table(LuaScript);
+                var index = 1;
+
+                foreach (var item in enumerable)
+                {
+                    table[index++] = ConvertToLua(item);
+                }
+
+                return DynValue.NewTable(table);
+            }
+
+            default:
+                return DynValue.FromObject(LuaScript, value);
+        }
+    }
+
+    private static object ConvertKey(object key)
+        => key is string text ? text : Convert.ToString(key, CultureInfo.InvariantCulture) ?? string.Empty;
 
     /// <summary>
     /// Creates a Lua callback that invokes the constructor matching the number of arguments passed from Lua.

tests/SquidStd.Tests/Scripting/Lua/LuaScriptEngineServiceTests.cs

@@ -59,6 +59,41 @@ public void AddManualModuleFunction_RegistersActionAndTypedFunction()
         Assert.Equal(12d, result.Data);
     }
 
+    [Fact]
+    public void ModuleFunctionReturningDictionary_MarshalsToLuaTable()
+    {
+        using var temp = new TempDirectory();
+        using var container = new Container();
+        using var engine = CreateEngine(temp, container);
+
+        engine.AddManualModuleFunction<double, Dictionary<string, object>>(
+            "itemModule",
+            "get",
+            id => new() { ["id"] = id, ["name"] = "Dagger", ["amount"] = 3d }
+        );
+
+        Assert.Equal(5d, engine.ExecuteFunction("item_module.get(5).id").Data);
+        Assert.Equal("Dagger", engine.ExecuteFunction("item_module.get(5).name").Data);
+        Assert.Equal(3d, engine.ExecuteFunction("item_module.get(5).amount").Data);
+    }
+
+    [Fact]
+    public void ModuleFunctionReturningList_MarshalsToLuaArrayTable()
+    {
+        using var temp = new TempDirectory();
+        using var container = new Container();
+        using var engine = CreateEngine(temp, container);
+
+        engine.AddManualModuleFunction<double, List<object>>(
+            "itemModule",
+            "contents",
+            _ => [1073741824d, 1073741825d, 1073741826d]
+        );
+
+        Assert.Equal(3d, engine.ExecuteFunction("#item_module.contents(1)").Data);
+        Assert.Equal(1073741825d, engine.ExecuteFunction("item_module.contents(1)[2]").Data);
+    }
+
     [Fact]
     public void AddSearchDirectory_AllowsRequireFromAdditionalDirectory()
     {