Thursday, 14 February 2008

PHP_CodeSniffer == JS_CodeSniffer?

There has been one item on my PHP_CodeSniffer todo list for a long time; to get PHP_CodeSniffer to enforce coding standards for JavaScript files. I've finally found the time to get going with this project and I've made good progress over the last couple of days.

My local copy of PHP_CodeSniffer now uses the file extension to determine which tokenizer to use to parse each file. I've moved the tokenizing code out of PHP_CodeSniffer_File into a PHP tokenizer and have added a new JS tokenizer. Once the file is tokenized, all existing sniffs can be run on it, but obviously most of the existing ones are only going to work correctly for PHP files.

The next step is to look at all the existing sniffs and identify those that are PHP only and those that would also work for JS files. Once that happens, each will be flagged using a protected member var so developers of coding standards know which tokenizers a sniff supports. I'll only be doing this for the Squiz and Generic standards to start with as I'm sure PEAR has no desire to start writing a JavaScript coding standard.

For developers who have written their own sniffs, you don't need to change anything to keep your existing sniffs and standards working. You only need to make changes if you want to start checking JavaScript files as well.

My overall goal is to get PHP_CodeSniffer to check all file types that PHP web developers would commonly use, including JavaScript, CSS, HTML and XML. It's going to take a while to get there, but JavaScript files are easily the most complex files to parse in that list, so I'm well on the way. I'm hoping to get this change into CVS sometime next week and get a release candidate out after I've written a decent number of JS sniffs.