diff --git a/.gitignore b/.gitignore
index 6ee0aa6..37f4810 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,4 @@
+/tmp/
 /vendor/
-*.phar
\ No newline at end of file
+*.phar
+cs-check.json
\ No newline at end of file
diff --git a/config/serviceManager.php b/config/serviceManager.php
index 6c6dea7..ef6afed 100644
--- a/config/serviceManager.php
+++ b/config/serviceManager.php
@@ -1,18 +1,21 @@
 <?php
+
 use Fbrinker\ExtensionCheck\Command\CheckCommand;
 use Fbrinker\ExtensionCheck\Command\CheckCommandFactory;
 use Fbrinker\ExtensionCheck\Extension\ExtensionCheck;
 use Fbrinker\ExtensionCheck\Extension\ExtensionCheckFactory;
 use Fbrinker\ExtensionCheck\Extension\ExtensionDetails;
+use Fbrinker\ExtensionCheck\Output\SymfonyStyleFactory;
 use Fbrinker\ExtensionCheck\Parser\FileParser;
 use Fbrinker\ExtensionCheck\Parser\FileParserFactory;
 use Laminas\ServiceManager\Factory\InvokableFactory;
 
 return [
     'factories' => [
-        CheckCommand::class =>CheckCommandFactory::class,
+        CheckCommand::class => CheckCommandFactory::class,
         ExtensionCheck::class => ExtensionCheckFactory::class,
         ExtensionDetails::class => InvokableFactory::class,
         FileParser::class => FileParserFactory::class,
+        SymfonyStyleFactory::class => InvokableFactory::class,
     ],
-];
\ No newline at end of file
+];
diff --git a/phpcs.xml b/phpcs.xml
new file mode 100644
index 0000000..7749ee0
--- /dev/null
+++ b/phpcs.xml
@@ -0,0 +1,24 @@
+<?xml version="1.0"?>
+<ruleset name="Skeleton coding standard">
+    <description>Skeleton coding standard</description>
+
+    <arg value="p"/>
+    <arg name="colors"/>
+    <arg name="cache" value="cs-check.json"/>
+    <arg name="parallel" value="8" />
+    <arg name="ignore" value="tests/assets"/>
+
+    <rule ref="PSR12">
+        <exclude name="Generic.Files.LineLength"/>
+    </rule>
+    <rule ref="Generic.Arrays.DisallowLongArraySyntax"/>
+    <rule ref="Squiz.WhiteSpace.SuperfluousWhitespace">
+        <properties>
+            <property name="ignoreBlankLines" value="false"/>
+        </properties>
+    </rule>
+
+    <file>src</file>
+    <file>tests</file>
+    <file>config</file>
+</ruleset>
\ No newline at end of file
diff --git a/phpstan.neon b/phpstan.neon
new file mode 100644
index 0000000..e51c96f
--- /dev/null
+++ b/phpstan.neon
@@ -0,0 +1,9 @@
+parameters:
+    level: max
+    inferPrivatePropertyTypeFromConstructor: true
+    paths:
+        - src/
+        - tests/
+    excludes_analyse:
+        - %currentWorkingDirectory%/src/TEST
+    tmpDir: tmp/phpstan
\ No newline at end of file
diff --git a/src/Command/CheckCommand.php b/src/Command/CheckCommand.php
index 34ffa47..c312993 100644
--- a/src/Command/CheckCommand.php
+++ b/src/Command/CheckCommand.php
@@ -1,4 +1,5 @@
 <?php
+
 declare(strict_types=1);
 
 namespace Fbrinker\ExtensionCheck\Command;
@@ -6,24 +7,27 @@ namespace Fbrinker\ExtensionCheck\Command;
 use Closure;
 use Fbrinker\ExtensionCheck\Extension\ExtensionCheck;
 use Fbrinker\ExtensionCheck\Extension\ExtensionDetails;
+use Fbrinker\ExtensionCheck\Output\SymfonyStyleFactory;
 use Fbrinker\ExtensionCheck\Parser\FileParser;
 use Symfony\Component\Console\Command\Command;
 use Symfony\Component\Console\Helper\ProgressBar;
 use Symfony\Component\Console\Input\InputArgument;
 use Symfony\Component\Console\Input\InputDefinition;
 use Symfony\Component\Console\Input\InputInterface;
-use Symfony\Component\Console\Input\InputOption;
 use Symfony\Component\Console\Output\OutputInterface;
 
 class CheckCommand extends Command
 {
+    private const ARG_DIRECTORY = 'directory';
+
     protected static $defaultName = 'check';
+    private $symfonyStyleFactory;
     private $fileParser;
     private $extensionDetails;
     private $extensionCheck;
 
     public function __construct(
-        $symfonyStyleFactory,
+        SymfonyStyleFactory $symfonyStyleFactory,
         FileParser $fileParser,
         ExtensionDetails $extensionDetails,
         ExtensionCheck $extensionCheck
@@ -42,7 +46,7 @@ class CheckCommand extends Command
             ->setHelp('This command allows you to check your extensions...')
             ->setDefinition(
                 new InputDefinition([
-                    new InputArgument('directory', InputArgument::OPTIONAL, "The directory to scan", "./"),
+                    new InputArgument(self::ARG_DIRECTORY, InputArgument::OPTIONAL, "The directory to scan", "./"),
                 ])
             );
     }
@@ -52,7 +56,13 @@ class CheckCommand extends Command
         $io = ($this->symfonyStyleFactory)($input, $output);
 
         $io->section("Analyzing Files");
-        $this->fileParser->scanForFiles($input->getArgument('directory'));
+
+        $scanDir = $input->getArgument(self::ARG_DIRECTORY);
+        if (empty($scanDir) || !\is_string($scanDir)) {
+            $scanDir = './';
+        }
+        $this->fileParser->scanForFiles($scanDir);
+
         $fileCount = $this->fileParser->getFileCount();
         $io->text(sprintf('Files: %d', $fileCount));
         $io->newLine();
@@ -66,7 +76,7 @@ class CheckCommand extends Command
 
         $progressBar->finish();
         $io->newLine(2);
-        $io->text(sprintf("Calls to check:", count($classes)));
+        $io->text("Calls to check:");
         $io->text(sprintf(
             "%d Classes, %d Functions, %d Constants",
             count($classes),
@@ -95,16 +105,17 @@ class CheckCommand extends Command
         $io->text(sprintf(
             "<fg=green>%d</> Used, <fg=red>%d</> Unused",
             count($usedExtensions),
-            count($unusedExtensions),
+            count($unusedExtensions)
         ));
 
         $io->section("Result");
         $io->text("Used Extensions:");
         $tmp = array_keys($usedExtensions);
         natcasesort($tmp);
-        foreach($tmp as $usedExtension) {
+        foreach ($tmp as $usedExtension) {
             $reason = $usedExtensions[$usedExtension];
-            $io->text(sprintf(' <fg=green>%s</> %s <comment>[Usage: %s]</>',
+            $io->text(sprintf(
+                ' <fg=green>%s</> %s <comment>[Usage: %s]</>',
                 "\u{2713}",
                 $usedExtension,
                 implode(", ", array_keys($reason))
@@ -114,8 +125,9 @@ class CheckCommand extends Command
         $io->newLine();
 
         $io->text("Unused Extensions:");
-        foreach($unusedExtensions as $unusedExtension) {
-            $io->text(sprintf(' <fg=red>%s</> %s',
+        foreach ($unusedExtensions as $unusedExtension) {
+            $io->text(sprintf(
+                ' <fg=red>%s</> %s',
                 "\u{2717}",
                 $unusedExtension
             ));
@@ -124,13 +136,15 @@ class CheckCommand extends Command
         return Command::SUCCESS;
     }
 
-    private function getProgressBarClosure(&$progressBar): Closure {
-        return function() use ($progressBar) {
+    private function getProgressBarClosure(ProgressBar $progressBar): Closure
+    {
+        return function () use ($progressBar) {
             $progressBar->advance();
         };
     }
 
-    private function getStyledProgressBar(OutputInterface $output, int $maxValue): ProgressBar {
+    private function getStyledProgressBar(OutputInterface $output, int $maxValue): ProgressBar
+    {
         $progressBar = new ProgressBar($output, $maxValue);
         $progressBar->setBarCharacter('<info>=</info>');
         $progressBar->setEmptyBarCharacter(' ');
@@ -138,4 +152,4 @@ class CheckCommand extends Command
 
         return $progressBar;
     }
-}
\ No newline at end of file
+}
diff --git a/src/Command/CheckCommandFactory.php b/src/Command/CheckCommandFactory.php
index e28e623..c072f79 100644
--- a/src/Command/CheckCommandFactory.php
+++ b/src/Command/CheckCommandFactory.php
@@ -1,23 +1,28 @@
 <?php
+
 declare(strict_types=1);
+
 namespace Fbrinker\ExtensionCheck\Command;
 
 use Fbrinker\ExtensionCheck\Extension\ExtensionCheck;
 use Fbrinker\ExtensionCheck\Extension\ExtensionDetails;
+use Fbrinker\ExtensionCheck\Output\SymfonyStyleFactory;
 use Fbrinker\ExtensionCheck\Parser\FileParser;
 use Interop\Container\ContainerInterface;
 use Laminas\ServiceManager\Factory\FactoryInterface;
-use Symfony\Component\Console\Style\SymfonyStyle;
 
 class CheckCommandFactory implements FactoryInterface
 {
+    /**
+     * @param array<mixed> $options
+     */
     public function __invoke(ContainerInterface $container, $requestedName, array $options = null)
     {
         return new CheckCommand(
-            new class { public function __invoke($input, $output) { return new SymfonyStyle($input, $output); } },
+            $container->get(SymfonyStyleFactory::class),
             $container->get(FileParser::class),
             $container->get(ExtensionDetails::class),
-            $container->get(ExtensionCheck::class),
+            $container->get(ExtensionCheck::class)
         );
     }
-}
\ No newline at end of file
+}
diff --git a/src/Extension/ExtensionCheck.php b/src/Extension/ExtensionCheck.php
index 60eb61d..b13a877 100644
--- a/src/Extension/ExtensionCheck.php
+++ b/src/Extension/ExtensionCheck.php
@@ -1,10 +1,13 @@
 <?php
+
 declare(strict_types=1);
+
 namespace Fbrinker\ExtensionCheck\Extension;
 
 use Closure;
 
-class ExtensionCheck {
+class ExtensionCheck
+{
 
     private $extensionDetails;
 
@@ -13,17 +16,29 @@ class ExtensionCheck {
         $this->extensionDetails = $extensionDetails;
     }
 
-    public function getUnused(array $usedExtensions) {
+    /**
+     * @param string[] $usedExtensions
+     * @return string[]
+     */
+    public function getUnused(array $usedExtensions): array
+    {
         return array_diff(
             $this->extensionDetails->getLoadedExtensions(),
             $usedExtensions
         );
     }
 
-    public function checkUsages(array $classes, array $functions, array $constants, Closure $callback) {
+    /**
+     * @param string[] $classes
+     * @param string[] $functions
+     * @param string[] $constants
+     * @return array<string,array<string,bool>>
+     */
+    public function checkUsages(array $classes, array $functions, array $constants, Closure $callback)
+    {
         $usedExtensions = [];
 
-        foreach($classes as $class) {
+        foreach ($classes as $class) {
             $extension = $this->checkClass($class);
 
             if (!empty($extension)) {
@@ -33,7 +48,7 @@ class ExtensionCheck {
             $callback();
         }
 
-        foreach($functions as $function) {
+        foreach ($functions as $function) {
             $extension = $this->checkFunction($function);
 
             if (!empty($extension)) {
@@ -43,7 +58,7 @@ class ExtensionCheck {
             $callback();
         }
 
-        foreach($constants as $constant) {
+        foreach ($constants as $constant) {
             $extension = $this->checkConstant($constant);
 
             if (!empty($extension)) {
@@ -54,11 +69,11 @@ class ExtensionCheck {
         }
 
         $tmp = array_keys($usedExtensions);
-        foreach($tmp as $usedExtension) {
+        foreach ($tmp as $usedExtension) {
             $requiredExtensions = $this->checkRequiredDependency($usedExtension);
 
             if (!empty($requiredExtensions)) {
-                foreach($requiredExtensions as $requiredExtension) {
+                foreach ($requiredExtensions as $requiredExtension) {
                     $usedExtensions[$requiredExtension]['dependency'] = true;
                 }
             }
@@ -69,7 +84,8 @@ class ExtensionCheck {
         return $usedExtensions;
     }
 
-    private function checkClass($class): ?string {
+    private function checkClass(string $class): ?string
+    {
         $classMap = $this->extensionDetails->getExtensionClassMap();
 
         if (!isset($classMap[$class])) {
@@ -79,7 +95,8 @@ class ExtensionCheck {
         return $classMap[$class];
     }
 
-    private function checkFunction($function): ?string {
+    private function checkFunction(string $function): ?string
+    {
         $functionMap = $this->extensionDetails->getExtensionFunctionMap();
 
         if (!isset($functionMap[$function])) {
@@ -89,7 +106,8 @@ class ExtensionCheck {
         return $functionMap[$function];
     }
 
-    private function checkConstant($function): ?string {
+    private function checkConstant(string $function): ?string
+    {
         $constantMap = $this->extensionDetails->getExtensionConstantMap();
 
         if (!isset($constantMap[$function])) {
@@ -99,7 +117,11 @@ class ExtensionCheck {
         return $constantMap[$function];
     }
 
-    private function checkRequiredDependency($extension): array {
+    /**
+     * @return string[]
+     */
+    private function checkRequiredDependency(string $extension): array
+    {
         $dependencyMap = $this->extensionDetails->getExtensionDependencyMap();
 
         if (!isset($dependencyMap[$extension]['required'])) {
@@ -108,5 +130,4 @@ class ExtensionCheck {
 
         return $dependencyMap[$extension]['required'];
     }
-
-}
\ No newline at end of file
+}
diff --git a/src/Extension/ExtensionCheckFactory.php b/src/Extension/ExtensionCheckFactory.php
index 33a6e89..20e7f8b 100644
--- a/src/Extension/ExtensionCheckFactory.php
+++ b/src/Extension/ExtensionCheckFactory.php
@@ -1,5 +1,7 @@
 <?php
+
 declare(strict_types=1);
+
 namespace Fbrinker\ExtensionCheck\Extension;
 
 use Interop\Container\ContainerInterface;
@@ -7,10 +9,13 @@ use Laminas\ServiceManager\Factory\FactoryInterface;
 
 class ExtensionCheckFactory implements FactoryInterface
 {
+    /**
+    * @param array<mixed> $options
+    */
     public function __invoke(ContainerInterface $container, $requestedName, array $options = null)
     {
         return new ExtensionCheck(
             $container->get(ExtensionDetails::class)
         );
     }
-}
\ No newline at end of file
+}
diff --git a/src/Extension/ExtensionDetails.php b/src/Extension/ExtensionDetails.php
index cc056b1..b15e25f 100644
--- a/src/Extension/ExtensionDetails.php
+++ b/src/Extension/ExtensionDetails.php
@@ -1,60 +1,90 @@
 <?php
+
 declare(strict_types=1);
+
 namespace Fbrinker\ExtensionCheck\Extension;
 
 use ReflectionExtension;
 
-class ExtensionDetails {
+class ExtensionDetails
+{
     private $loadedExtensions;
-    private $extensionMap = [];
+
+    /** @var ExtensionMap|null */
+    private $extensionMap;
 
     public function __construct()
     {
         $this->loadedExtensions = array_map('strtolower', get_loaded_extensions());
     }
 
-    public function getLoadedExtensions(): array {
+    /**
+     * @return string[]
+     */
+    public function getLoadedExtensions(): array
+    {
         natcasesort($this->loadedExtensions);
         return $this->loadedExtensions;
     }
 
-    public function getLoadedExtensionsCount(): int {
+    public function getLoadedExtensionsCount(): int
+    {
         return count($this->loadedExtensions);
     }
 
-    public function getExtensionClassMap(): array {
+    /**
+     * @return array<string,string>
+     */
+    public function getExtensionClassMap(): array
+    {
         if (empty($this->extensionMap)) {
             $this->buildExtensionMaps();
         }
 
-        return $this->extensionMap['classes'] ?? [];
+        return $this->extensionMap->classes ?? [];
     }
 
-    public function getExtensionFunctionMap(): array {
+    /**
+     * @return array<string,string>
+     */
+    public function getExtensionFunctionMap(): array
+    {
         if (empty($this->extensionMap)) {
             $this->buildExtensionMaps();
         }
 
-        return $this->extensionMap['functions'] ?? [];
+        return $this->extensionMap->functions ?? [];
     }
 
-    public function getExtensionConstantMap(): array {
+    /**
+     * @return array<string,string>
+     */
+    public function getExtensionConstantMap(): array
+    {
         if (empty($this->extensionMap)) {
             $this->buildExtensionMaps();
         }
 
-        return $this->extensionMap['constants'] ?? [];
+        return $this->extensionMap->constants ?? [];
     }
 
-    public function getExtensionDependencyMap(): array {
+    /**
+     * @return array<string,array<string,string[]>>
+     */
+    public function getExtensionDependencyMap(): array
+    {
         if (empty($this->extensionMap)) {
             $this->buildExtensionMaps();
         }
 
-        return $this->extensionMap['dependencies'] ?? [];
+        return $this->extensionMap->dependencies ?? [];
     }
 
-    private function buildExtensionMaps(array $extensionsToExclude = []) {
+    /**
+     * @param string[] $extensionsToExclude
+     */
+    private function buildExtensionMaps(array $extensionsToExclude = []): void
+    {
         $extensionClasses = $extensionFunctions = $extensionConstants = $extensionDependencies = $uncheckedExtensions = [];
         foreach ($this->loadedExtensions as $loadedExtension) {
             if (in_array(strtolower($loadedExtension), array_map('strtolower', $extensionsToExclude))) {
@@ -106,13 +136,12 @@ class ExtensionDetails {
             }
         }
 
-        $this->extensionMap = [
-            'classes' => $extensionClasses,
-            'functions' => $extensionFunctions,
-            'constants' => $extensionConstants,
-            'dependencies' => $extensionDependencies,
-            'unchecked' => $uncheckedExtensions
-        ];
+        $this->extensionMap = new ExtensionMap(
+            $extensionClasses,
+            $extensionFunctions,
+            $extensionConstants,
+            $extensionDependencies,
+            $uncheckedExtensions
+        );
     }
-
-}
\ No newline at end of file
+}
diff --git a/src/Extension/ExtensionMap.php b/src/Extension/ExtensionMap.php
new file mode 100644
index 0000000..e7859d8
--- /dev/null
+++ b/src/Extension/ExtensionMap.php
@@ -0,0 +1,42 @@
+<?php
+
+namespace Fbrinker\ExtensionCheck\Extension;
+
+class ExtensionMap
+{
+    /** @var array<string,string> */
+    public $classes;
+
+    /** @var array<string,string> */
+    public $functions;
+
+    /** @var array<string,string> */
+    public $constants;
+
+    /** @var array<string,array<string,string[]>> */
+    public $dependencies;
+
+    /** @var string[] */
+    public $unchecked;
+
+    /**
+     * @param array<string,string> $classes
+     * @param array<string,string> $functions
+     * @param array<string,string> $constants
+     * @param array<string,array<string,string[]>> $dependencies
+     * @param string[] $unchecked
+     */
+    public function __construct(
+        array $classes = [],
+        array $functions = [],
+        array $constants = [],
+        array $dependencies = [],
+        array $unchecked = []
+    ) {
+        $this->classes = $classes;
+        $this->functions = $functions;
+        $this->constants = $constants;
+        $this->dependencies = $dependencies;
+        $this->unchecked = $unchecked;
+    }
+}
diff --git a/src/Output/SymfonyStyleFactory.php b/src/Output/SymfonyStyleFactory.php
new file mode 100644
index 0000000..a3c1650
--- /dev/null
+++ b/src/Output/SymfonyStyleFactory.php
@@ -0,0 +1,15 @@
+<?php
+
+namespace Fbrinker\ExtensionCheck\Output;
+
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Output\OutputInterface;
+use Symfony\Component\Console\Style\SymfonyStyle;
+
+class SymfonyStyleFactory
+{
+    public function __invoke(InputInterface $input, OutputInterface $output): SymfonyStyle
+    {
+        return new SymfonyStyle($input, $output);
+    }
+}
diff --git a/src/Parser/FileParser.php b/src/Parser/FileParser.php
index 81988bb..3b2d2f1 100644
--- a/src/Parser/FileParser.php
+++ b/src/Parser/FileParser.php
@@ -1,16 +1,21 @@
 <?php
+
 declare(strict_types=1);
+
 namespace Fbrinker\ExtensionCheck\Parser;
 
 use Closure;
+use Error;
 use Fbrinker\ExtensionCheck\Parser\Visitors\ClassCollector;
 use Fbrinker\ExtensionCheck\Parser\Visitors\ConstantCollector;
 use Fbrinker\ExtensionCheck\Parser\Visitors\FunctionCollector;
 use PhpParser\NodeTraverser;
 use PhpParser\ParserFactory;
 use Symfony\Component\Finder\Finder;
+use Throwable;
 
-class FileParser {
+class FileParser
+{
     private $finder;
 
     public function __construct(Finder $finder)
@@ -18,7 +23,8 @@ class FileParser {
         $this->finder = $finder;
     }
 
-    public function scanForFiles(string $directory): void {
+    public function scanForFiles(string $directory): void
+    {
         $this->finder->files()->name('*.php')->in($directory);
         $this->finder->sortByName();
     }
@@ -28,8 +34,12 @@ class FileParser {
         return $this->finder->count();
     }
 
-    public function parseFiles(Closure $callback) {
-        $parser = (new ParserFactory)->create(ParserFactory::PREFER_PHP7);
+    /**
+     * @return array<int,string[]>
+     */
+    public function parseFiles(Closure $callback): array
+    {
+        $parser = (new ParserFactory())->create(ParserFactory::PREFER_PHP7);
 
         $traverser = new NodeTraverser();
 
@@ -42,9 +52,19 @@ class FileParser {
         $constantCollector = new ConstantCollector();
         $traverser->addVisitor($constantCollector);
 
-        foreach($this->finder as $file) {
+        foreach ($this->finder as $file) {
             $content = $file->getContents();
-            $stmts = $parser->parse($content);
+            $stmts = [];
+
+            try {
+                $stmts = $parser->parse($content);
+            } catch (Throwable $e) {
+                echo $e->getMessage();
+            }
+
+            if (empty($stmts)) {
+                continue;
+            }
 
             $traverser->traverse($stmts);
             $callback();
@@ -56,4 +76,4 @@ class FileParser {
             $constantCollector->getCollected(),
         ];
     }
-}
\ No newline at end of file
+}
diff --git a/src/Parser/FileParserFactory.php b/src/Parser/FileParserFactory.php
index 21113e5..769ba32 100644
--- a/src/Parser/FileParserFactory.php
+++ b/src/Parser/FileParserFactory.php
@@ -1,5 +1,7 @@
 <?php
+
 declare(strict_types=1);
+
 namespace Fbrinker\ExtensionCheck\Parser;
 
 use Interop\Container\ContainerInterface;
@@ -8,10 +10,13 @@ use Symfony\Component\Finder\Finder;
 
 class FileParserFactory implements FactoryInterface
 {
+    /**
+    * @param array<mixed> $options
+    */
     public function __invoke(ContainerInterface $container, $requestedName, array $options = null)
     {
         return new FileParser(
             new Finder()
         );
     }
-}
\ No newline at end of file
+}
diff --git a/src/Parser/Visitors/ClassCollector.php b/src/Parser/Visitors/ClassCollector.php
index 7890574..bd55242 100644
--- a/src/Parser/Visitors/ClassCollector.php
+++ b/src/Parser/Visitors/ClassCollector.php
@@ -1,28 +1,37 @@
 <?php
+
 declare(strict_types=1);
+
 namespace Fbrinker\ExtensionCheck\Parser\Visitors;
 
 use PhpParser\Node;
 use PhpParser\NodeVisitorAbstract;
 
-class ClassCollector extends NodeVisitorAbstract implements CollectorInferface {
+class ClassCollector extends NodeVisitorAbstract implements CollectorInferface
+{
+
+    /**
+    * @var array<string,bool> $classes
+    */
     private $classes = [];
 
-    public function getCollected(): array {
+    public function getCollected(): array
+    {
         $list = array_keys($this->classes);
         natcasesort($list);
 
         return array_values($list);
     }
 
-    public function enterNode(Node $node) {
+    public function enterNode(Node $node)
+    {
         if ($node instanceof Node\Stmt\Class_) {
             if (!empty($node->extends)) {
                 $this->classes[$node->extends->toString()] = true;
             }
 
             if (!empty($node->implements)) {
-                foreach($node->implements as $implement) {
+                foreach ($node->implements as $implement) {
                     $this->classes[$implement->toString()] = true;
                 }
             }
@@ -35,7 +44,7 @@ class ClassCollector extends NodeVisitorAbstract implements CollectorInferface {
         }
 
         if ($node instanceof Node\Expr\New_) {
-            if (!empty($node->class) && $node->class->name instanceof Node\Name) {
+            if (!empty($node->class) && $node->class instanceof Node\Name) {
                 $this->classes[$node->class->toString()] = true;
             }
         }
@@ -45,5 +54,7 @@ class ClassCollector extends NodeVisitorAbstract implements CollectorInferface {
                 $this->classes[$node->class->toString()] = true;
             }
         }
+
+        return null;
     }
-}
\ No newline at end of file
+}
diff --git a/src/Parser/Visitors/CollectorInferface.php b/src/Parser/Visitors/CollectorInferface.php
index fb903b8..2d991e5 100644
--- a/src/Parser/Visitors/CollectorInferface.php
+++ b/src/Parser/Visitors/CollectorInferface.php
@@ -1,7 +1,13 @@
 <?php
+
 declare(strict_types=1);
+
 namespace Fbrinker\ExtensionCheck\Parser\Visitors;
 
-interface CollectorInferface {
+interface CollectorInferface
+{
+    /**
+     * @return string[]
+     */
     public function getCollected(): array;
-}
\ No newline at end of file
+}
diff --git a/src/Parser/Visitors/ConstantCollector.php b/src/Parser/Visitors/ConstantCollector.php
index 607c9b4..9fa6d3b 100644
--- a/src/Parser/Visitors/ConstantCollector.php
+++ b/src/Parser/Visitors/ConstantCollector.php
@@ -1,25 +1,35 @@
 <?php
+
 declare(strict_types=1);
+
 namespace Fbrinker\ExtensionCheck\Parser\Visitors;
 
 use PhpParser\Node;
 use PhpParser\NodeVisitorAbstract;
 
-class ConstantCollector extends NodeVisitorAbstract implements CollectorInferface {
+class ConstantCollector extends NodeVisitorAbstract implements CollectorInferface
+{
+    /**
+    * @var array<string,bool> $constants
+    */
     private $constants = [];
 
-    public function getCollected(): array {
+    public function getCollected(): array
+    {
         $list = array_keys($this->constants);
         natcasesort($list);
 
         return array_values($list);
     }
 
-    public function enterNode(Node $node) {
+    public function enterNode(Node $node)
+    {
         if ($node instanceof Node\Expr\ConstFetch) {
             if (!empty($node->name) && $node->name instanceof Node\Name) {
                 $this->constants[$node->name->toString()] = true;
             }
         }
+
+        return null;
     }
-}
\ No newline at end of file
+}
diff --git a/src/Parser/Visitors/FunctionCollector.php b/src/Parser/Visitors/FunctionCollector.php
index 8d0c268..af0b75d 100644
--- a/src/Parser/Visitors/FunctionCollector.php
+++ b/src/Parser/Visitors/FunctionCollector.php
@@ -1,25 +1,35 @@
 <?php
+
 declare(strict_types=1);
+
 namespace Fbrinker\ExtensionCheck\Parser\Visitors;
 
 use PhpParser\Node;
 use PhpParser\NodeVisitorAbstract;
 
-class FunctionCollector extends NodeVisitorAbstract implements CollectorInferface {
+class FunctionCollector extends NodeVisitorAbstract implements CollectorInferface
+{
+    /**
+    * @var array<string,bool> $functions
+    */
     private $functions = [];
 
-    public function getCollected(): array {
+    public function getCollected(): array
+    {
         $list = array_keys($this->functions);
         natcasesort($list);
 
         return array_values($list);
     }
 
-    public function enterNode(Node $node) {
+    public function enterNode(Node $node)
+    {
         if ($node instanceof Node\Expr\FuncCall) {
             if (!empty($node->name) && $node->name instanceof Node\Name) {
                 $this->functions[$node->name->toString()] = true;
             }
         }
+
+        return null;
     }
-}
\ No newline at end of file
+}