Currently the CLI engine looks explicitly for filenames that end in a .js see:

It would be a nice feature for files which use shebangs to infer the interpreter from #!/usr/bin/env node or similar when no extension is found.

else if (path.extname(filename) === "") {
   // one of the three methods below
}

I have thought about a couple of ways to make this work:

• Read the first n bytes to see if contains #! and node
• Use libmagic or file(1) to determine file type
• Allow the user to explicitly state the files which are to be linted as config.

By allowing this we can allow users who write JS on the server side using d8 or spidermonkey to explicitly define the interpreter that will be used at execution.