[browser][wasm] Add Function tests. (dotnet#38323)

* Add Function tests.

* Format code.

src/libraries/System.Runtime.InteropServices.JavaScript/tests/AssemblyInfo.cs

@@ -2,4 +2,4 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using Xunit;
+using Xunit;

src/libraries/System.Runtime.InteropServices.JavaScript/tests/System/Runtime/InteropServices/JavaScript/JavaScriptTests.cs

@@ -56,34 +56,65 @@ public static void CoreTypes()
 
             var arr10 = new Uint8Array(sharedArr50);
             Assert.Equal(50, arr10.Length);
-            
+
             var arr11 = new Uint16Array(sharedArr50);
             Assert.Equal(25, arr11.Length);
-            
+
             var arr12 = new Uint32Array(sharedArr40);
             Assert.Equal(10, arr12.Length);
-            
+
             var arr13 = new Int8Array(sharedArr50);
             Assert.Equal(50, arr13.Length);
-            
+
             var arr14 = new Int16Array(sharedArr40);
             Assert.Equal(20, arr14.Length);
-            
+
             var arr15 = new Int32Array(sharedArr40);
             Assert.Equal(10, arr15.Length);
-            
+
             var arr16 = new Float32Array(sharedArr40);
             Assert.Equal(10, arr16.Length);
-            
+
             var arr17 = new Float64Array(sharedArr40);
             Assert.Equal(5, arr17.Length);
         }
 
         [Fact]
-        public static void FunctionSumCall()
+        public static void FunctionSum()
         {
+            // The Difference Between call() and apply()
+            // The difference is:
+            //      The call() method takes arguments separately.
+            //      The apply() method takes arguments as an array.
             var sum = new Function("a", "b", "return a + b");
             Assert.Equal(8, (int)sum.Call(null, 3, 5));
+
+            Assert.Equal(13, (int)sum.Apply(null, new object[] { 6, 7 }));
+        }
+
+        [Fact]
+        public static void FunctionMath()
+        {
+            JSObject math = (JSObject)Runtime.GetGlobalObject("Math");
+            Assert.NotNull(math);
+
+            Function mathMax = (Function)math.GetObjectProperty("max");
+            Assert.NotNull(mathMax);
+
+            var maxValue = (int)mathMax.Apply(null, new object[] { 5, 6, 2, 3, 7 });
+            Assert.Equal(7, maxValue);
+
+            maxValue = (int)mathMax.Call(null, 5, 6, 2, 3, 7);
+            Assert.Equal(7, maxValue);
+
+            Function mathMin = (Function)((JSObject)Runtime.GetGlobalObject("Math")).GetObjectProperty("min");
+            Assert.NotNull(mathMin);
+
+            var minValue = (int)mathMin.Apply(null, new object[] { 5, 6, 2, 3, 7 });
+            Assert.Equal(2, minValue);
+
+            minValue = (int)mathMin.Call(null, 5, 6, 2, 3, 7);
+            Assert.Equal(2, minValue);
         }
     }
 }