There is not a section of Virginia Code dedicated to employment agreements. Nor is there a litmus test which allows employees to determine whether or not the agreement they have signed is enforceable.
The law in Virginia on the subject is found in common law or case law. This means, that each case, contract and relationship will be analyzed by the court individually.
Unless your ex-colleague just litigated whether or not the same non-compete you signed is reasonable, you have to re-invent the wheel on each and every non-compete case. That is why employers often add allegations like trade secret violation, conversion, etc. If they have to litigate the breach of contract issue, might as well add in a few extra claims to scare the employee? (Or at least this is the conversation I assume attorneys have with their corporate clients).
Employees should also be prepared with legal counsel if they are going to leave and break an agreement.
If each contract is considered individually, so will the facts of your situation. So when people call us and ask whether their contracts are valid under Virginia law, we tell them we review the agreement, advise future action, defend in court, but ultimately that is up to the judge.