Javascript Function Pruner

prune.php

<?php

if (count($argv) < 2) {
	die("Please enter a filename");
}

$filename = $argv[1];
$funcNameRegex = '(?P<func>[a-zA-Z0-9_$]+)';

$contents = file_get_contents($filename);
if (! $contents) {
	die("No data for file \"$filename\"");
}

$funcNameRegexes = Array(
	'/[\'"]?'.$funcNameRegex.'[\'"]\s*:\s*function/i',
	'/function\s+'.$funcNameRegex.'\s*\(/i',
	'/var\s+'.$funcNameRegex.'\s*=\s*function/i'
);

$nameLocations = array();
$useLocations = array();

foreach ($funcNameRegexes as $regex) {
	if (preg_match_all($regex, $contents, $output, PREG_OFFSET_CAPTURE)) {
		foreach ($output['func'] as $out) {
			$nameLocations[$out[0]] []= $out[1];
		}
	}
}

$funcUseRegexes = Array(
	'/that\.'.$funcNameRegex.'\(/i', 
	'/this\.'.$funcNameRegex.'\(/i', 
	'/\b'.$funcNameRegex.'\(/i',
	'/[\(,]\s*'.$funcNameRegex.'\s*[\),]/i'
);

foreach ($funcUseRegexes as $regex) {
	if (preg_match_all($regex, $contents, $output, PREG_OFFSET_CAPTURE)) {
		foreach ($output['func'] as $out) {
			$useLocations[$out[0]] []= $out[1];
		}
	}
}

$output = array();

$notUsed = array();

foreach ($nameLocations as $name => $defined) {
	$output [$name] = array(
		'defined' => $defined,
		'used' => array()
	);
	if (! isset($useLocations[$name])) {
		$notUsed [$name] = $defined;
	} else {
		$output[$name]['used'] = $useLocations[$name];
	}
}

foreach ($notUsed as $name => $defined_locations) {
	echo "\033[44m\033[1;37m function $name \033[0m\n";
	echo "  Defined at\n   - line ";
	echo join("\n   - line ", $defined_locations);
	echo "\n";
}

This script will detect unused functions within a single javascript file.