CamelCase2Human.php

<?php

/**
 * @param string $input
 * @return mixed|string
 */
function CamelCase2Human($input)
{
    $original = $input;
    
    if (strpos($input, '\\') !== false) {
        $input = explode('\\', $input);
        reset($input);
        $input = end($input);
    }

    if (!preg_match('#^tests#i', $input)) {
        $input = preg_replace('#^(test)#i', '', $input);
    }
    $input = preg_replace('#(test)$#i', '', $input);

    $output = preg_replace(array('/(?<=[^A-Z])([A-Z])/', '/(?<=[^0-9])([0-9])/'), ' $0', $input);
    $output = ucwords($output);
    $output = trim($output);
    
    if (strcasecmp($original, $output) === 0) {
        return $original;
    }
    
    if (strlen($output) == 0) {
        return $original;
    }

    return $output;
}

$tests = array(
    'LocalBusiness'                               => 'Local Business',
    'CivicStructureBuilding'                      => 'Civic Structure Building',
    'getUserMobilePhoneNumber'                    => 'Get User Mobile Phone Number',
    'bandGuitar1'                                 => 'Band Guitar 1',
    'band2Guitar123'                              => 'Band 2 Guitar 123',
    'CustomerIDWithSomeOtherJETWords'             => 'Customer IDWith Some Other JETWords',

    'testCustomerIDWithSomeOtherJETWords'         => 'Customer IDWith Some Other JETWords',
    'TESTCustomerIDWithSomeOtherJETWords'         => 'Customer IDWith Some Other JETWords',
    'TestCustomerIDWithSomeOtherJETWords'         => 'Customer IDWith Some Other JETWords',

    'SmetDenis\\SimpleTypes\\PerformanceTest'     => 'Performance',
    'SmetDenis\\SimpleTypes\\testPerformanceTest' => 'Performance',
    
    'Tests suite'                                 => 'Tests suite',
    'Tests test'                                  => 'Tests',
    'Test test'                                   => 'Test test',
);

foreach ($tests AS $input => $expected) {

    $output = CamelCase2Human($input);

    echo $input . ' : '.($output === $expected ? 'OK' : '<strong style="color:red;">fail</strong> ' . $expected ) . '<br>';
    echo '<pre>' . $output . '</pre><hr/>';
    
}