public void ShouldSetClrProperties() { // Ensure assembly is loaded var a = typeof(System.Windows.Forms.Form); var b = a.Assembly; // Force loading in Release mode, otherwise code is optimized const string script = @" var frm = new System.Windows.Forms.Form(); frm.Text = 'Test'; return frm.Text; "; var result = new JintEngine() .AddPermission(new UIPermission(PermissionState.Unrestricted)) .AllowClr() .Run(script); Assert.AreEqual("Test", result.ToString()); }