public void TestIfCompanyExistOnAdd()
{
var mockSet = new Mock <DbSet <Company> >();
var mockContext = new Mock <CompanyDBEntities>();
mockContext.Setup(m => m.Companies).Returns(mockSet.Object);
var companyContext = new CompanyDBContext(mockContext.Object);
companyContext.AddCompany(new Company()
{
CompanyId = 1, CompanyName = "Test",
Email = "*****@*****.**", LastName = "Testing", PhoneNumber = 123456
});
mockSet.Verify(m => m.Add(It.IsAny <Company>()), Times.Once());
}