How do you write a unit test for a regex pattern?

Is it possible? Would it require a existing whitewashed and/or blackl开发者_开发问答isted datasets, or not? How would you know an exception did not exist?

whitelists and blacklists sounds a good approach, I don't think you can "prove" it will work without exception so empirical verification is appropriate and in keeping with the spirit of unit testing

as you think up more complex/edge-case examples to test with, just add them and see if it still works, thus building a test suite in which you have ever greater levels of confidence

also, answered previously very thoroughly here

How do you unit test regular expressions?

You might want to look at the following link with an identical discussion that has several good solutions:

How do you unit test regular expressions?
How do you unit test regular expressions?