A Git pre-commit hook rejecting no-descriptive Phing and Ant build files

pre-commit-phing

#!/usr/bin/php
<?php
define('DEPENDENT_EXTENSION', 'SimpleXML');

if (!extension_loaded(DEPENDENT_EXTENSION)) {
    $consoleMessage = sprintf(
        "Skipping build file checks as the '%s' extension isn't available.", 
        DEPENDENT_EXTENSION
    );
    echo $consoleMessage . PHP_EOL;
    exit(0);
}

define('MIN_TARGET_DESCRIPTION_LENGTH', 10);
define('TARGET_DESCRIPTION_ATTRIBUTE', 'description');
define('TARGET_NAME_ATTRIBUTE', 'name');
define('CHECK_DESCRIPTION_LENGTH', true);

$possibleBuildFileNames = array(
    'build.xml.dist',
    'build.xml-dist',
    'build-dist.xml',
    'build.xml',
    'personal-build.xml'
);

$violations = getAllBuildFileViolationsOfCommit($possibleBuildFileNames);
fireBackPossibleViolationsAndExitAccordingly($violations);

function getAllBuildFileViolationsOfCommit(array $possibleBuildFileNames)
{
    $filesOfCommit = array();
    $gitCommand = 'git diff --cached --name-only';
    
    exec($gitCommand, $filesOfCommit, $commandReturnCode);
    
    $allViolations = array();
    foreach ($filesOfCommit as $file) {
      if (in_array(basename($file), $possibleBuildFileNames)) {
          $violations = checkBuildFileForViolations($file);
          if (count($violations) > 0) {
            $allViolations[$file] = $violations;
          }
      }
    }

    return $allViolations;
}

/**
 *  @param  array $allViolations
 *  @return void
 */
function fireBackPossibleViolationsAndExitAccordingly(array $allViolations)
{
    if (count($allViolations) > 0) {
        foreach ($allViolations as $buildFile => $violations) {

            $buildFileConsoleMessageHeader = sprintf("Build file '%s':", $buildFile);
            echo $buildFileConsoleMessageHeader . PHP_EOL;

            foreach ($violations as $violationMessage) {
                $buildFileConsoleMessageLine = sprintf(" + %s", $violationMessage);
                echo $buildFileConsoleMessageLine . PHP_EOL;
            }
        }
        if (count($allViolations) > 1) {
            $rejectCommitConsoleMessage = sprintf(
                "Therefore rejecting the commit of build files [ %s ].", 
                implode(', ', array_keys($allViolations))
            );
        } else {
            $rejectCommitConsoleMessage = sprintf(
                "Therefore rejecting the commit of build file [ %s ].", 
                implode(', ', array_keys($allViolations))
            );
        }

        echo $rejectCommitConsoleMessage . PHP_EOL;
        exit(1);
    }
    exit(0);
}
/**
 *  @param  string $buildfile
 *  @return array
 */
function checkBuildFileForViolations($buildFile) {
    if (!file_exists($buildFile)) {
        return array();
    }

    $buildfileXml = file_get_contents($buildFile);
    $buildXml = new SimpleXMLElement($buildfileXml);
    $allBuildTargets = $buildXml->xpath("//target");
    $violations = array();

    if (count($allBuildTargets) > 0) {

        $targetsWithNoDescription = $targetsWithTooShortDescription = array();

        foreach ($allBuildTargets as $buildTarget) {

            $actualTragetAttributes = $buildTarget->attributes();
            $allUsedTragetAttributes = array();
            $actualTargetName = null;

            foreach ($actualTragetAttributes as $attribute => $value) {
                $allUsedTragetAttributes[] = $attribute;

                if ($attribute === TARGET_NAME_ATTRIBUTE) {
                    $actualTargetName = $value;
                }

                if (CHECK_DESCRIPTION_LENGTH === true && 
                    $attribute === TARGET_DESCRIPTION_ATTRIBUTE && 
                    strlen($value) < MIN_TARGET_DESCRIPTION_LENGTH) 
                {
                    $targetsWithTooShortDescription[] = $actualTargetName;
                }
            }   

            if (!in_array(TARGET_DESCRIPTION_ATTRIBUTE, $allUsedTragetAttributes)) {
                $targetsWithNoDescription[] = $actualTargetName;
            }
        }
        if (count($targetsWithNoDescription) > 0) {
            if (count($targetsWithNoDescription) > 1) {
                $violations[] = sprintf(
                    "Build targets [ %s ] don't have mandatory descriptions.", 
                    implode(', ', $targetsWithNoDescription)
                );
            } else {
                $violations[] = sprintf(
                    "Build target [ %s ] doesn't have a mandatory description.", 
                    implode(', ', $targetsWithNoDescription)
                );
            }
        }

        if (count($targetsWithTooShortDescription) > 0) {
            if (count($targetsWithTooShortDescription) > 1) {
                $violations[] = sprintf(
                    "Build targets [ %s ] don't have an adequate target description length.", 
                    implode(', ', $targetsWithTooShortDescription),
                    MIN_TARGET_DESCRIPTION_LENGTH
                );
            } else {
                $violations[] = sprintf(
                    "Build target [ %s ] doesn't have an adequate target description length.", 
                    implode(', ', $targetsWithTooShortDescription),
                    MIN_TARGET_DESCRIPTION_LENGTH
                );
            }
        }
    }
    return $violations;
}