Add E2E test for interop that uses an object reference to a JS function

Author: oroztocil

src/Components/test/E2ETest/Tests/InteropTest.cs

@@ -107,6 +107,8 @@ public void CanInvokeInteropMethods()
             ["invokeNewWithClassConstructorAsync.dataProperty"] = "abraka",
             ["invokeNewWithClassConstructorAsync.function"] = "6",
             ["invokeNewWithNonConstructorAsync"] = "Success",
+            // Function reference tests
+            ["changeFunctionViaObjectReferenceAsync"] = "42"
         };
 
         var expectedSyncValues = new Dictionary<string, string>
@@ -171,6 +173,8 @@ public void CanInvokeInteropMethods()
             ["invokeNewWithClassConstructor.dataProperty"] = "abraka",
             ["invokeNewWithClassConstructor.function"] = "6",
             ["invokeNewWithNonConstructor"] = "Success",
+            // Function reference tests
+            ["changeFunctionViaObjectReference"] = "42"
         };
 
         // Include the sync assertions only when running under WebAssembly

src/Components/test/testassets/BasicTestApp/InteropComponent.razor

@@ -301,6 +301,13 @@
             InvokeNewTests();
         }
 
+        await FunctionReferenceAsyncTests();
+
+        if (shouldSupportSyncInterop)
+        {
+            FunctionReferenceTests();
+        }
+
         Invocations = invocations;
         DoneWithInterop = true;
     }
@@ -601,6 +608,24 @@
         }
     }
 
+    private async Task FunctionReferenceAsyncTests()
+    {
+        var funcRef = await JSRuntime.GetValueAsync<IJSObjectReference>("jsInteropTests.nonConstructorFunction");
+        var testClassRef = await JSRuntime.InvokeNewAsync("jsInteropTests.TestClass", "abraka");
+        await testClassRef.SetValueAsync("getTextLength", funcRef);
+        ReturnValues["changeFunctionViaObjectReferenceAsync"] = (await testClassRef.InvokeAsync<int>("getTextLength")).ToString();
+    }
+
+    private void FunctionReferenceTests()
+    {
+        var inProcRuntime = ((IJSInProcessRuntime)JSRuntime);
+
+        var funcRef = inProcRuntime.GetValue<IJSObjectReference>("jsInteropTests.nonConstructorFunction");
+        var testClassRef = inProcRuntime.InvokeNew("jsInteropTests.TestClass", "abraka");
+        testClassRef.SetValue("getTextLength", funcRef);
+        ReturnValues["changeFunctionViaObjectReference"] = testClassRef.Invoke<int>("getTextLength").ToString();
+    }
+
     public class PassDotNetObjectByRefArgs
     {
         public string StringValue { get; set; }