fix-variable-names.php

#!/usr/bin/env php
<?php
/** 
 * DISCLAIMER: Even though I tried my best to prevent anything bad from happening,
 * I can't guarantee that your code won't break after using this script on it.
 * 
 * What does this script do?
 * It replaces all occurences of $FooBar and $foo_bar with properly camelCased $fooBar.
 * Replacements also include references to class properties like $this->foo_bar and $this->FooBar
 * 
 * Note: Function calls are being ignored (for now)
 * If you find a bug, feel free to comment.
 **/
$content = file_get_contents($argv[1]);
$tokens  = token_get_all($content);

$toReplace = [];
foreach($tokens as $key => $token) {
	// Check T_VARIABLE ($foo_bar) and T_STRING with preceding T_OBJECT_OPERATOR ($this->foo_bar)
    if (is_array($token) 
    	&& (
    		$token[0] === 320                  // T_VARIABLE
    		|| (
    			$token[0] === 319              // T_STRING
    			&& $tokens[$key -1][0] === 366 // T_OBJECT_OPERATOR
    			&& $tokens[$key +1] !== '('    // Ignore function calls
    		) 
    	)
    ) {
    	$firstLetterPos = strpos($token[1], "$") === 0 ? 1 : 0;
    	$firstLetter = substr($token[1], $firstLetterPos , 1);
    	// Get triggered if you find underscores or if the first letter of the variable name is uppercased
    	if (strpos($token[1], "_") !== false || $firstLetter !== strtolower($firstLetter)) {
	        // Make every letter preceded by an underscore uppercased
	        $proper = ucwords($token[1], '_');
	        // Remove underscores from token
	        $proper = str_replace("_", "", $proper);
	        // Ensure the first letter is always lowercased
	        $proper = substr_replace($proper, strtolower($firstLetter), $firstLetterPos, 1);
	        // Ensure to only replace the string if it's preceded by an T_OBJECT_OPERATOR
	        if ($tokens[$key -1][0] === 366) {
	        	$toReplace['>' . $token[1]] = '>' . $proper;
	        } else {
		        $toReplace[$token[1]] = $proper;
		    }
	    }
	}
}

foreach ($toReplace as $find => $replace) {
	echo $find . ' => ' . $replace . "\t";
	if (strpos($content, $replace) === false) {
		$content = str_replace($find, $replace, $content);
	} else {
		echo 'Can\'t safely replace! ' . $replace . ' already found in the code!';
	}
	echo PHP_EOL;
}

file_put_contents($argv[1], $content);