function onFile( error, file ) {
		var errs;
		if ( error ) {
			debug( 'Encountered an error when reading file: %s', error.message );
			return done( error );
		}
		debug( 'Successfully read file.' );

		debug( 'Linting namespace...' );
		errs = analyze( file );
		debug( 'Finished linting namespace.' );
		if ( errs ) {
			debug( 'Found %d lint errors: %s', errs.length, JSON.stringify( errs ) );
			return done( null, errs );
		}
		done();
	}
Callback invoked upon reading file contents.

@private
@param {(Error|null)} error - error object
@param {(string|Buffer)} file - file contents
@returns {void}