Question

I have the following property:

public double TotalHours
{
    get
    {
        return (from session in sessions
                let ts = session.End.Subtract(session.Start)
                select ts.TotalHours).Sum();
    }
}

The property should sum all hours done in all sessions.
What do I need to test in order to ensure that the property is always summing all the hours from all sessions?

Answer 1

It’s basically a case of working out appropriate sample data. For example, you might want to try tests for:

• No sessions
• A single session
• Multiple sessions
• Sessions with no start time or not end time
• A session where the end is before the start
• A session where the end equals the start

Maybe you’ve got other data validation to ensure that the “dodgy-sounding” situations don’t occur, but those are the kinds of things I’d think about.