Can you Have multiple unit test files

I have two unit test files in Visual Studio, for example test1.cs and test2.cs... When I select run all tests, it only runs the test from test1.cs. How can I make visual studio run tests from both test1.cs and test2.cs?

Additional information: If I select a test method from test2.cs, the output will tell me "No tests found to run."

(test2.cs == ADPReportClassTest.cs)

using Microsoft.VisualStudio.TestTools.UnitTesting;
namespace EmployeeRefreshTest.tests
{
    [TestClass]
    class ADPReportClassTest
    {
        TestContext TestContext { get; set; }

        [TestMethod]
        [DataSource("System.Data.SqlClient", "Server=Localhost;Database=Test_Employee_Refresh;Integrated Security=Yes", "ADPREPORTCLASS_Tuples", DataAccessMethod.Sequential)]
        public void Checkconstructor()
        {
            string filename = TestContext.DataRow["TestFileName"].ToString();
            Assert.AreEqual(filename, filename);
        }
    }
}