Merge pull request #27 from koculu/24-feature-add-an-interface-to-customize-retrieving-type-members

Add await expression handler interface.

Author: koculu

src/Topaz.Test/AwaitTests.cs

@@ -4,6 +4,7 @@
 using System.Collections.Generic;
 using System.Linq;
 using System.Reflection;
+using System.Threading;
 using System.Threading.Tasks;
 using Tenray.Topaz.API;
 using Tenray.Topaz.Interop;
@@ -150,6 +151,54 @@ public void AsyncEnumerator()
 ");
         Assert.That(model.result2, Is.EqualTo(5));
     }
+
+    [Test]
+    public void CustomAwaitHandler()
+    {
+        var engine = new TopazEngine(new TopazEngineSetup { AwaitExpressionHandler = new CustomAwaitExpressionHandler() });
+        dynamic model = new JsObject();
+        engine.SetValue("test", this);
+        engine.SetValue("model", model);
+        engine.ExecuteScriptAsync(@"
+model.result1 = await test.GenericTask();
+").Wait();
+        Assert.That(model.result1, Is.EqualTo(33));
+        engine.ExecuteScript(@"
+model.result2 = await test.GenericTask();
+");
+        Assert.That(model.result2, Is.EqualTo(33));
+    }
+
+    [Test]
+    public void CustomAwaitHandler2()
+    {
+        var engine = new TopazEngine(new TopazEngineSetup { AwaitExpressionHandler = new CustomAwaitExpressionHandler() });
+        dynamic model = new JsObject();
+        engine.SetValue("test", this);
+        engine.SetValue("model", model);
+        engine.ExecuteScriptAsync(@"
+var t = test.GenericTask();
+model.result1 = await t;
+").Wait();
+        Assert.That(model.result1, Is.EqualTo(33));
+        engine.ExecuteScript(@"
+var t = test.GenericTask();
+model.result2 = await t;
+");
+        Assert.That(model.result2, Is.EqualTo(33));
+    }
+}
+
+class CustomAwaitExpressionHandler : IAwaitExpressionHandler
+{
+    public async Task<object> HandleAwaitExpression(object awaitObject, CancellationToken token)
+    {
+        if (awaitObject is Task<int> task)
+        {
+            return await task;
+        }
+        return awaitObject;
+    }
 }
 
 class CustomMemberInfoProvider : IMemberInfoProvider

src/Topaz/AstHandlers/AsyncHandlers/Expressions/AwaitExpressionHandler.cs

@@ -10,9 +10,14 @@ internal static partial class AwaitExpressionHandler
     internal async static ValueTask<object> ExecuteAsync(ScriptExecutor scriptExecutor, Node expression, CancellationToken token)
     {
         var expr = (AwaitExpression)expression;
-        var result = await scriptExecutor.ExecuteStatementAsync(expr.Argument, token);
+        var result = await scriptExecutor.ExecuteExpressionAndGetValueAsync(expr.Argument, token);
         if (result == null)
             return null;
+        var awaitHandler = scriptExecutor.TopazEngine.AwaitExpressionHandler;
+        if (awaitHandler != null)
+        {
+            return await awaitHandler.HandleAwaitExpression(result, token);
+        }
         if (result is Task task)
         {
             var type = task.GetType();

src/Topaz/AstHandlers/Expressions/AwaitExpressionHandler.cs

@@ -11,7 +11,16 @@ internal static partial class AwaitExpressionHandler
     internal static object Execute(ScriptExecutor scriptExecutor, Node expression, CancellationToken token)
     {
         var expr = (AwaitExpression)expression;
-        var result = scriptExecutor.ExecuteStatement(expr.Argument, token);
+        var result = scriptExecutor.ExecuteExpressionAndGetValue(expr.Argument, token);
+        var awaitHandler = scriptExecutor.TopazEngine.AwaitExpressionHandler;
+        if (result == null)
+            return null;
+        if (awaitHandler != null)
+        {
+            var task1 = awaitHandler.HandleAwaitExpression(result, token);
+            task1.Wait(token);
+            return task1.Result;
+        }
         if (result is Task task)
         {
             task.Wait(token);

src/Topaz/Directory.Build.props

@@ -5,8 +5,8 @@
     <Authors>Ahmed Yasin Koculu</Authors>
     <PackageId>Topaz</PackageId>
     <Title>Topaz</Title>
-    <ProductVersion>1.3.8.0</ProductVersion>
-    <Version>1.3.8.0</Version>
+    <ProductVersion>1.3.9.0</ProductVersion>
+    <Version>1.3.9.0</Version>
     <Authors>Ahmed Yasin Koculu</Authors>
     <AssemblyTitle>Topaz</AssemblyTitle>
     <Description>Multithreaded Javascript Engine for .NET</Description>

src/Topaz/Interop/IAwaitExpressionHandler.cs

@@ -0,0 +1,9 @@
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace Tenray.Topaz.Interop;
+
+public interface IAwaitExpressionHandler
+{
+    Task<object> HandleAwaitExpression(object awaitObject, CancellationToken token);
+}

src/Topaz/TopazEngine.cs

@@ -37,6 +37,8 @@ public sealed class TopazEngine : ITopazEngine
 
     public IMemberInfoProvider MemberInfoProvider { get; }
 
+    public IAwaitExpressionHandler AwaitExpressionHandler { get; }
+
     internal ScriptExecutorPool ScriptExecutorPool = new();
 
     public TopazEngine(TopazEngineSetup setup = null)
@@ -52,6 +54,7 @@ public TopazEngine(TopazEngineSetup setup = null)
         ObjectProxyRegistry = setup.ObjectProxyRegistry ?? new DictionaryObjectProxyRegistry();
         extensionMethodRegistry = new();
         MemberInfoProvider = setup.MemberInfoProvider ?? new MemberInfoProvider();
+        AwaitExpressionHandler = setup.AwaitExpressionHandler;
         ValueConverter = setup.ValueConverter ?? new DefaultValueConverter();
         DefaultObjectProxy = setup.DefaultObjectProxy ?? new ObjectProxyUsingReflection(null, extensionMethodRegistry, ValueConverter, MemberInfoProvider);
         DelegateInvoker = setup.DelegateInvoker ?? new DelegateInvoker(ValueConverter);

src/Topaz/TopazEngineSetup.cs

@@ -24,4 +24,6 @@ public sealed class TopazEngineSetup
     public IValueConverter ValueConverter { get; set; }
 
     public IMemberInfoProvider MemberInfoProvider { get; set; }
+
+    public IAwaitExpressionHandler AwaitExpressionHandler { get; set; }
 }