PHP script to detect potentially unused Magento 2 extensions

detect-unused-magento2-extensions.php

<?php
require __DIR__ . '/app/bootstrap.php';

use Magento\Framework\App\Bootstrap;
use Magento\Framework\App\ResourceConnection;
use Magento\Framework\Module\ModuleListInterface;
use Magento\Framework\Module\Dir\Reader as ModuleDirReader;

$bootstrap = Bootstrap::create(BP, $_SERVER);
$obj = $bootstrap->getObjectManager();
$appState = $obj->get(\Magento\Framework\App\State::class);
$appState->setAreaCode('adminhtml');

$moduleList = $obj->get(ModuleListInterface::class);
$moduleDirReader = $obj->get(ModuleDirReader::class);
$resource = $obj->get(ResourceConnection::class);
$db = $resource->getConnection();
$scopeConfig = $obj->get(\Magento\Framework\App\Config\ScopeConfigInterface::class);

function logInfo(string $msg): void {
    echo "[INFO] $msg\n";
}

function logWarn(string $msg): void {
    echo "[WARN] $msg\n";
}

function getModuleDeclaredTables(string $modulePath): array {
    $tables = [];

    $dbSchema = $modulePath . '/etc/db_schema.xml';
    if (file_exists($dbSchema)) {
        logInfo("Parsing: $dbSchema");
        $xml = simplexml_load_file($dbSchema);
        foreach ($xml->table as $table) {
            $tables[] = (string) $table['name'];
        }
    }

    $legacyInstallSchema = glob($modulePath . '/Setup/InstallSchema.php');
    foreach ($legacyInstallSchema as $file) {
        logInfo("Scanning legacy InstallSchema: $file");
        $contents = file_get_contents($file);
        preg_match_all('/->createTable\(\$setup->getTable\([\'"]([^\'"]+)[\'"]\)\)/', $contents, $matches);
        $tables = array_merge($tables, $matches[1]);
    }

    return array_unique($tables);
}

echo "=== Unused Extensions Detection ===\n\n";

$config = include BP . '/app/etc/config.php';
$unusedModules = [];

foreach ($moduleList->getAll() as $moduleName => $info) {
    logInfo("Processing module: $moduleName");
    $modulePath = $moduleDirReader->getModuleDir('', $moduleName);
    $declaredTables = getModuleDeclaredTables($modulePath);

    $reason = [];

    // 1. Tables declared but all empty or missing
    $tablesEmpty = true;
    foreach ($declaredTables as $table) {
        if (!$db->isTableExists($table)) {
            logWarn("Table '$table' does not exist");
            continue;
        }

        $rowCount = (int) $db->fetchOne("SELECT COUNT(*) FROM `$table`");
        logInfo("Table '$table' has $rowCount rows");

        if ($rowCount > 0) {
            $tablesEmpty = false;
            break;
        }
    }

    if ($declaredTables && $tablesEmpty) {
        $reason[] = 'All declared tables empty or missing';
    }

    // 2. EAV attributes declared but unused
    $eavTableSuffixes = ['varchar', 'int', 'text', 'decimal', 'datetime'];
    $attributeIds = [];

    foreach ($eavTableSuffixes as $suffix) {
        $table = "catalog_product_entity_$suffix";
        if (!$db->isTableExists($table)) continue;
        $ids = $db->fetchCol("SELECT DISTINCT attribute_id FROM $table");
        $attributeIds = array_merge($attributeIds, $ids);
    }

    $attributeIds = array_unique($attributeIds);
    $moduleAttributes = $db->fetchCol(
        "SELECT attribute_id FROM eav_attribute WHERE source_model LIKE ?", ["%$moduleName%"]
    );

    $unusedAttrs = array_diff($moduleAttributes, $attributeIds);
    if ($moduleAttributes && count($unusedAttrs) === count($moduleAttributes)) {
        $reason[] = 'All declared EAV attributes unused';
    }

    // 3. Module is disabled in app/etc/config.php
    $isDisabled = !isset($config['modules'][$moduleName]) || (int) $config['modules'][$moduleName] === 0;
    if ($isDisabled) {
        $reason[] = 'Module is disabled in app/etc/config.php';
    }

    // 4. Optional: frontend output disabled
    $configDisabled = $scopeConfig->isSetFlag("advanced/modules_disable_output/{$moduleName}");
    if ($configDisabled) {
        $reason[] = 'Frontend output is disabled via config';
    }

    // Add to summary if anything is worth flagging
    if (!empty($reason)) {
        $unusedModules[] = [
            'name'   => $moduleName,
            'reason' => implode('; ', $reason),
        ];
    }
}

// Output summary table
if (!empty($unusedModules)) {
    echo "\n=== Summary: Possibly Unused Extensions ===\n\n";
    $maxLen = max(array_map(fn($m) => strlen($m['name']), $unusedModules));
    $col1 = str_pad('Extension', $maxLen + 2);
    echo "$col1 | Reason\n";
    echo str_repeat('-', strlen($col1) + 40) . "\n";

    foreach ($unusedModules as $mod) {
        $name = str_pad($mod['name'], $maxLen + 2);
        echo "$name | {$mod['reason']}\n";
    }
} else {
    echo "\nNo apparently unused extensions found.\n";
}