Description: ------------ When using PHP/CodeSniffer/Standards/Squiz/Sniffs/Debug/JSLintSniff.php, I do not get a warning/notice/error when either of the required paths is not set. I don't have the possibility to find out something is wrong. When someone uses this sniff, phpcs should tell the error and exit with a non-zero exit code.

This isn't a bug - it is completely intentional. But I'll leave it as a feature request, although I'm not exactly sure how it would work. Maybe a config option in the ruleset.xml file. The reason it works like this is that a standard might include everything because it wants access to all these nice external tools, but many developers wont actually use them during day-to-day development. If it threw an error, the standard could never be used until all external tools were installed and functional. On some platforms, this is impossible. So all an error would lead to is a standard that never gets widely used, or at least one that takes a lot of extra time to get working.