Added logic to insert whitespace after NOT operators
This is for adding space after NOT operators to conform with the WordPress PHP Coding Standards. See the section on logical comparisons under spacing: https://make.wordpress.org/core/handbook/coding-standards/php/#space-usage
Can you post a few "before and after" examples of this new behavior?
Actually, I think this would be a good time to introduce some phpunit tests that cover all the branches touched by the pull request: T_IF, T_WHILE etc.
I know that, compared to implementing a new feature, writing tests seems like a chore, but it's necessary, particularly for such a script, with many many branches.
If you're not familiar with PHPUnit, just give me the test cases, i.e. "this bit of incorrect PHP should look like this after I run it through wp-phptidy", I'll translate them to working PHPUnit tests.