Added failing test case for issue #37610 - [System.Text.Json] Serializing class that has array of children of the same class throws StackOverflowException

src/System.Text.Json/tests/Serialization/CyclicTests.cs

@@ -17,5 +17,16 @@ public static void WriteCyclicFail()
             // We don't allow cycles; we throw InvalidOperation instead of an unrecoverable StackOverflow.
             Assert.Throws<InvalidOperationException>(() => JsonSerializer.ToString(obj));
         }
+
+        [Fact]
+        [ActiveIssue(37313)]
+        public static void WriteTestClassWithArrayOfElementsOfTheSameClassWithoutCyclesDoesNotFail()
+        {
+            TestClassWithArrayOfElementsOfTheSameClass obj = new TestClassWithArrayOfElementsOfTheSameClass();
+
+            //It shouldn't throw when there is no real cycle reference, and just empty object is created
+            string json = JsonSerializer.ToString(obj);
+            Assert.Equal(@"{}", json);
+        }
     }
 }

src/System.Text.Json/tests/Serialization/TestClasses.cs

@@ -396,6 +396,11 @@ public void Initialize()
         }
     }
 
+    public class TestClassWithArrayOfElementsOfTheSameClass
+    {
+        public TestClassWithArrayOfElementsOfTheSameClass[] Array { get; set; }
+    }
+
     public class TestClassWithGenericList : ITestClass
     {
         public List<string> MyData { get; set; }