I was reviewing a pull request today when came across something along some complicated boolean logic and it reminded me of the sections of Robert C Martin's Clean Code: A Handbook of Agile Software Craftsmanship. In it, he discusses Bad Comments as well as Using Descriptive Naming.

When looking at boolean logic, I like to combine to two principals to give context to why I'm doing something.

Let's look at a contrived example. Some best practices with time retrieval and hard coded values are left for clarity.

if(person.IsBornInUsa && 
   person.DateOfBirth >= DateTime.Now.AddYears(-35) && 
   person.ResidencyDate >= DateTime.Now.AddYears(-14)
{ 
    person.SetQualifications(true)
}

We can add context to our actions by modifying things slightly:

var meetsPresidentialQualifications = person.IsBornInUsa &&
    person.DateOfBirth <= DateTime.Now.AddYears(-35) &&
    person.ResidencyDate <= DateTime.Now.AddYears(-14);

if(meetsPresidentialQualifications)
{
  person.SetQualifications(true)
}

It's a small change, but it lets us focus on what's important with less mental gymnastics.