[unity]之前一个扩展函数的用例没生效，其次之前没有验证传递值正确性的用例，参数错位是扩展函数实现容易出现的问题

Author: chexiongsheng

unity/test/Src/Cases/CrossLang/ExtensionTest.cs

@@ -50,6 +50,12 @@ public static string Extension2<T1, T2>(this T1 a, T2 b) where T1 : ExtensionTes
         {
             return (string.Format("Extension2<{0},{1}>", typeof(T1), typeof(T2)));
         }
+
+        [UnityEngine.Scripting.Preserve]
+        public static string Extension3<T>(this T a, string b) where T : ExtensionTestHelper
+        {
+            return b;
+        }
     }
 
     [TestFixture]
@@ -111,6 +117,7 @@ public void ExtensionGenerateBaseTest()
             Assert.AreEqual(res.ToString(), "Puerts.UnitTest.ExtensionTestHelper");
         }
 
+        [Test]
         public void ExtensionGenerateBaseTest_1()
         {
             var jsEnv = UnitTestEnv.GetEnv();
@@ -124,6 +131,20 @@ public void ExtensionGenerateBaseTest_1()
             Assert.AreEqual(res.ToString(), "Puerts.UnitTest.ExtensionTestHelper");
         }
 
+        [Test]
+        public void ExtensionGenerateBaseTest_3()
+        {
+            var jsEnv = UnitTestEnv.GetEnv();
+            var res = jsEnv.Eval<string>(@"
+                (function() {
+                    let obj = new CS.Puerts.UnitTest.ExtensionTestHelper();
+                    let res = obj.Extension3('123');
+                    return res;
+                })()
+            ");
+            Assert.AreEqual(res, "123");
+        }
+
         [Test]
         public void ExtensionGenerateBaseBase1Test_2()
         {