Merge pull request #4856 from elsa-workflows/issue(4849)

Remove StringObjectDictionaryConverter and update JintJavaScriptEvaluator

src/modules/Elsa.JavaScript/Elsa.JavaScript.csproj

@@ -19,7 +19,7 @@
 
     <ItemGroup>
         <PackageReference Include="System.Linq.Async" Version="6.0.1" />
-        <PackageReference Include="Jint" Version="3.0.0-beta-2057" />
+        <PackageReference Include="Jint" Version="3.0.0" />
     </ItemGroup>
 
 </Project>

src/modules/Elsa.JavaScript/Helpers/ObjectArrayHelper.cs

@@ -0,0 +1,39 @@
+using System.Collections;
+
+namespace Elsa.JavaScript.Helpers;
+
+/// <summary>
+/// Contains helper methods for working with object arrays.
+/// </summary>
+public static class ObjectArrayHelper
+{
+    /// <summary>
+    /// Determines if the specified object is an array-like CLR collection.
+    /// </summary>
+    public static bool DetermineIfObjectIsArrayLikeClrCollection(Type type)
+    {
+        var isDictionary = typeof(IDictionary).IsAssignableFrom(type);
+        
+        if (isDictionary)
+            return false;
+        
+        if (typeof(ICollection).IsAssignableFrom(type))
+            return true;
+        
+        foreach (var interfaceType in type.GetInterfaces())
+        {
+            if (!interfaceType.IsGenericType)
+            {
+                continue;
+            }
+
+            if (interfaceType.GetGenericTypeDefinition() == typeof(IReadOnlyCollection<>)
+                || interfaceType.GetGenericTypeDefinition() == typeof(ICollection<>))
+            {
+                return true;
+            }
+        }
+
+        return false;
+    }
+}

src/modules/Elsa.JavaScript/Helpers/StringObjectDictionaryConverter.cs

@@ -1,40 +0,0 @@
-using System.Collections;
-
-namespace Elsa.JavaScript.Helpers;
-
-/// <summary>
-/// Contains methods for converting dictionaries with string keys and object values by replacing IList fields with Array fields.
-/// </summary>
-public static class StringObjectDictionaryConverter
-{
-    /// <summary>
-    /// Recursively converts all IList fields of an ExpandoObject to Array fields.
-    /// This allows JS expressions to properly use Array methods on lists, such as .length, filter, etc.
-    /// </summary>
-    public static object? ConvertListsToArray(object? value)
-    {
-        if (value is not IDictionary<string, object> dictionary) 
-            return value;
-
-        // Copy the dictionary to avoid modifying the original.
-        dictionary = new Dictionary<string, object>(dictionary);
-        var keys = dictionary.Keys.ToList();
-        foreach (var key in keys)
-        {
-            if (dictionary[key] is IList && dictionary[key].GetType().IsGenericType)
-            {
-                var list = (IList)dictionary[key];
-                var elementType = dictionary[key].GetType().GetGenericArguments()[0];
-                var array = Array.CreateInstance(elementType, list.Count);
-                list.CopyTo(array, 0);
-                dictionary[key] = array;
-            }
-            else
-            {
-                ConvertListsToArray(dictionary[key]);
-            }
-        }
-
-        return dictionary;
-    }
-}

src/modules/Elsa.JavaScript/Services/JintJavaScriptEvaluator.cs

@@ -11,6 +11,7 @@ using Elsa.JavaScript.Options;
 using Elsa.Mediator.Contracts;
 using Humanizer;
 using Jint;
+using Jint.Runtime.Interop;
 using Microsoft.Extensions.Options;
 
 // ReSharper disable ConvertClosureToMethodGroup
@@ -56,6 +57,17 @@ public class JintJavaScriptEvaluator : IJavaScriptEvaluator
         {
             if (_jintOptions.AllowClrAccess)
                 opts.AllowClr();
+
+            // Wrap objects in ObjectWrapper instances and set their prototype to Array.prototype if they are array-like.
+            opts.SetWrapObjectHandler((engine, target, type) =>
+            {
+                var instance = new ObjectWrapper(engine, target);
+
+                if (ObjectArrayHelper.DetermineIfObjectIsArrayLikeClrCollection(target.GetType()))
+                    instance.Prototype = engine.Intrinsics.Array.PrototypeObject;
+
+                return instance;
+            });
         });
 
         configureEngine?.Invoke(engine);
@@ -122,7 +134,7 @@ public class JintJavaScriptEvaluator : IJavaScriptEvaluator
         var inputs = context.GetWorkflowInputs();
 
         foreach (var input in inputs)
-            engine.SetValue($"get{input.Name}", (Func<object?>)(() => StringObjectDictionaryConverter.ConvertListsToArray(input.Value)));
+            engine.SetValue($"get{input.Name}", (Func<object?>)(() => input.Value));
     }
 
     private static void CreateVariableAccessors(Engine engine, ExpressionExecutionContext context)

test/integration/Elsa.IntegrationTests/Scenarios/JavaScriptListAndArray/Tests.cs

@@ -0,0 +1,57 @@
+using System.Collections.Generic;
+using System.Dynamic;
+using Elsa.JavaScript.Helpers;
+using Jint;
+using Jint.Runtime.Interop;
+using Xunit;
+
+namespace Elsa.IntegrationTests.Scenarios.JavaScriptListAndArray;
+
+/// <summary>
+/// Contains test cases for the functionality of the Engine class to enable list and array-like objects to be used in JavaScript as arrays.
+/// </summary>
+public class Tests
+{
+    private readonly Engine _engine;
+
+    public Tests()
+    {
+        _engine = new Engine(cfg => cfg
+            .SetWrapObjectHandler((engine, target, type) =>
+            {
+                var instance = new ObjectWrapper(engine, target);
+                
+                if (ObjectArrayHelper.DetermineIfObjectIsArrayLikeClrCollection(target.GetType()))
+                    instance.Prototype = engine.Intrinsics.Array.PrototypeObject;
+
+                return instance;
+            })
+        );
+    }
+
+    [Fact(DisplayName = "Can access list properties as arrays")]
+    public void Test1()
+    {
+        var person = new ExpandoObject();
+
+        person.TryAdd("name", "John");
+        person.TryAdd("age", 12);
+
+        var languages = new List<object>
+        {
+            "English",
+            "French"
+        };
+
+        person.TryAdd("languages", languages);
+
+        var obj = new ExpandoObject();
+        obj.TryAdd("persons", new List<object> { person });
+        _engine.SetValue("o", obj);
+
+        var name = _engine.Evaluate("o.persons.filter(x => x.age == 12)[0].name").ToString();
+        var language = _engine.Evaluate("o.persons[0].languages.filter(x => x == 'English')[0]").ToString();
+        Assert.Equal("John", name);
+        Assert.Equal("English", language);
+    }
+}