From 30b55ae15035faddb993446fbbdc3ea746a616f4 Mon Sep 17 00:00:00 2001
From: Matias Griese <matias@trilbymedia.com>
Date: Fri, 24 Sep 2021 12:19:41 +0300
Subject: [PATCH] Phpstan fixes

---
 system/src/Grav/Common/Assets/BaseAsset.php   |  6 +++-
 system/src/Grav/Common/Assets/Pipeline.php    |  2 +-
 .../Common/Assets/Traits/AssetUtilsTrait.php  |  6 ++--
 system/src/Grav/Common/Backup/Backups.php     |  2 +-
 system/src/Grav/Common/Cache.php              |  8 ++---
 system/src/Grav/Common/Data/Blueprint.php     |  4 +--
 system/src/Grav/Common/Data/Data.php          |  2 +-
 system/src/Grav/Common/Data/Validation.php    |  4 +--
 system/src/Grav/Common/Debugger.php           |  2 +-
 system/src/Grav/Common/Filesystem/Folder.php  |  5 +--
 .../Grav/Common/Filesystem/ZipArchiver.php    |  7 ++--
 system/src/Grav/Common/Flex/FlexObject.php    |  2 +-
 .../Flex/Types/Pages/PageCollection.php       |  7 ++--
 .../Common/Flex/Types/Pages/PageIndex.php     | 19 +++++++----
 .../Common/Flex/Types/Pages/PageObject.php    | 12 ++++---
 .../Types/Pages/Traits/PageLegacyTrait.php    |  5 ++-
 .../Flex/Types/Users/UserCollection.php       |  4 +--
 .../Common/Flex/Types/Users/UserIndex.php     |  4 +--
 system/src/Grav/Common/Grav.php               | 24 +++++++-------
 system/src/Grav/Common/Helpers/Excerpts.php   |  7 +++-
 system/src/Grav/Common/Helpers/LogViewer.php  | 22 +++++++------
 system/src/Grav/Common/Iterator.php           |  4 +--
 .../Grav/Common/Language/LanguageCodes.php    | 13 ++------
 system/src/Grav/Common/Page/Collection.php    |  2 +-
 system/src/Grav/Common/Page/Page.php          |  4 +--
 system/src/Grav/Common/Page/Pages.php         | 32 ++++++++++++-------
 system/src/Grav/Common/Scheduler/Job.php      |  2 +-
 system/src/Grav/Common/Security.php           |  6 ++--
 system/src/Grav/Common/Session.php            |  4 +--
 system/src/Grav/Common/Taxonomy.php           |  2 +-
 system/src/Grav/Common/Utils.php              | 20 ++++--------
 31 files changed, 125 insertions(+), 118 deletions(-)

diff --git a/system/src/Grav/Common/Assets/BaseAsset.php b/system/src/Grav/Common/Assets/BaseAsset.php
index 192ea81cd..a115ce9ec 100644
--- a/system/src/Grav/Common/Assets/BaseAsset.php
+++ b/system/src/Grav/Common/Assets/BaseAsset.php
@@ -92,6 +92,10 @@ abstract class BaseAsset extends PropertyObject
      */
     public function init($asset, $options)
     {
+        if (!$asset) {
+            return false;
+        }
+
         $config = Grav::instance()['config'];
         $uri = Grav::instance()['uri'];
 
@@ -259,6 +263,6 @@ abstract class BaseAsset extends PropertyObject
      */
     protected function cssRewrite($file, $dir, $local)
     {
-        return;
+        return '';
     }
 }
diff --git a/system/src/Grav/Common/Assets/Pipeline.php b/system/src/Grav/Common/Assets/Pipeline.php
index 2e499f98f..948104ab9 100644
--- a/system/src/Grav/Common/Assets/Pipeline.php
+++ b/system/src/Grav/Common/Assets/Pipeline.php
@@ -254,7 +254,7 @@ class Pipeline extends PropertyObject
                 $old_url = ltrim($old_url, '/');
             }
 
-            $new_url = ($local ? $this->base_url: '') . $old_url;
+            $new_url = ($local ? $this->base_url : '') . $old_url;
 
             return str_replace($matches[2], $new_url, $matches[0]);
         }, $file);
diff --git a/system/src/Grav/Common/Assets/Traits/AssetUtilsTrait.php b/system/src/Grav/Common/Assets/Traits/AssetUtilsTrait.php
index ac6e55a31..3f5a690fb 100644
--- a/system/src/Grav/Common/Assets/Traits/AssetUtilsTrait.php
+++ b/system/src/Grav/Common/Assets/Traits/AssetUtilsTrait.php
@@ -68,8 +68,6 @@ trait AssetUtilsTrait
     protected function gatherLinks(array $assets, $css = true)
     {
         $buffer = '';
-
-
         foreach ($assets as $id => $asset) {
             $local = true;
 
@@ -135,7 +133,7 @@ trait AssetUtilsTrait
 
         $imports = [];
 
-        $file = (string)preg_replace_callback($regex, function ($matches) use (&$imports) {
+        $file = (string)preg_replace_callback($regex, static function ($matches) use (&$imports) {
             $imports[] = $matches[0];
 
             return '';
@@ -200,7 +198,7 @@ trait AssetUtilsTrait
         }
 
         if ($this->timestamp) {
-            if (Utils::contains($asset, '?') || $querystring) {
+            if ($querystring || Utils::contains($asset, '?')) {
                 $querystring .=  '&' . $this->timestamp;
             } else {
                 $querystring .= '?' . $this->timestamp;
diff --git a/system/src/Grav/Common/Backup/Backups.php b/system/src/Grav/Common/Backup/Backups.php
index 9483b15f7..b70def96f 100644
--- a/system/src/Grav/Common/Backup/Backups.php
+++ b/system/src/Grav/Common/Backup/Backups.php
@@ -222,7 +222,7 @@ class Backups
             $backup_root = rtrim(GRAV_ROOT . $backup_root, '/');
         }
 
-        if (!file_exists($backup_root)) {
+        if (!$backup_root || !file_exists($backup_root)) {
             throw new RuntimeException("Backup location: {$backup_root} does not exist...");
         }
 
diff --git a/system/src/Grav/Common/Cache.php b/system/src/Grav/Common/Cache.php
index a961904de..a50351836 100644
--- a/system/src/Grav/Common/Cache.php
+++ b/system/src/Grav/Common/Cache.php
@@ -141,7 +141,7 @@ class Cache extends Getters
         $uniqueness = substr(md5($uri->rootUrl(true) . $this->config->key() . GRAV_VERSION), 2, 8);
 
         // Cache key allows us to invalidate all cache on configuration changes.
-        $this->key = ($prefix ? $prefix : 'g') . '-' . $uniqueness;
+        $this->key = ($prefix ?: 'g') . '-' . $uniqueness;
         $this->cache_dir = $grav['locator']->findResource('cache://doctrine/' . $uniqueness, true, true);
         $this->driver_setting = $this->config->get('system.cache.driver');
         $this->driver = $this->getCacheDriver();
@@ -618,11 +618,7 @@ class Cache extends Getters
      */
     public function isVolatileDriver($setting)
     {
-        if (in_array($setting, ['apc', 'apcu', 'xcache', 'wincache'])) {
-            return true;
-        }
-
-        return false;
+        return in_array($setting, ['apc', 'apcu', 'xcache', 'wincache'], true);
     }
 
     /**
diff --git a/system/src/Grav/Common/Data/Blueprint.php b/system/src/Grav/Common/Data/Blueprint.php
index 29a26369c..287819939 100644
--- a/system/src/Grav/Common/Data/Blueprint.php
+++ b/system/src/Grav/Common/Data/Blueprint.php
@@ -37,7 +37,7 @@ class Blueprint extends BlueprintForm
     /** @var string|null */
     protected $scope;
 
-    /** @var BlueprintSchema */
+    /** @var BlueprintSchema|null */
     protected $blueprintSchema;
 
     /** @var object|null */
@@ -54,7 +54,7 @@ class Blueprint extends BlueprintForm
      */
     public function __clone()
     {
-        if ($this->blueprintSchema) {
+        if (null !== $this->blueprintSchema) {
             $this->blueprintSchema = clone $this->blueprintSchema;
         }
     }
diff --git a/system/src/Grav/Common/Data/Data.php b/system/src/Grav/Common/Data/Data.php
index 67fb0a831..4de437dcb 100644
--- a/system/src/Grav/Common/Data/Data.php
+++ b/system/src/Grav/Common/Data/Data.php
@@ -264,7 +264,7 @@ class Data implements DataInterface, ArrayAccess, \Countable, JsonSerializable,
      */
     public function blueprints()
     {
-        if (!$this->blueprints) {
+        if (null === $this->blueprints) {
             $this->blueprints = new Blueprint();
         } elseif (is_callable($this->blueprints)) {
             // Lazy load blueprints.
diff --git a/system/src/Grav/Common/Data/Validation.php b/system/src/Grav/Common/Data/Validation.php
index 7ee60e415..c5b21ffac 100644
--- a/system/src/Grav/Common/Data/Validation.php
+++ b/system/src/Grav/Common/Data/Validation.php
@@ -608,7 +608,7 @@ class Validation
      */
     public static function typeColor($value, array $params, array $field)
     {
-        return preg_match('/^\#[0-9a-fA-F]{3}[0-9a-fA-F]{3}?$/u', $value);
+        return (bool)preg_match('/^\#[0-9a-fA-F]{3}[0-9a-fA-F]{3}?$/u', $value);
     }
 
     /**
@@ -1189,7 +1189,7 @@ class Validation
      */
     public static function filterItem_List($value, $params)
     {
-        return array_values(array_filter($value, function ($v) {
+        return array_values(array_filter($value, static function ($v) {
             return !empty($v);
         }));
     }
diff --git a/system/src/Grav/Common/Debugger.php b/system/src/Grav/Common/Debugger.php
index 6a1e256b9..b8143f68b 100644
--- a/system/src/Grav/Common/Debugger.php
+++ b/system/src/Grav/Common/Debugger.php
@@ -332,7 +332,7 @@ class Debugger
             return new Response(404, $headers, json_encode($response));
         }
 
-        $data = is_array($data) ? array_map(function ($item) {
+        $data = is_array($data) ? array_map(static function ($item) {
             return $item->toArray();
         }, $data) : $data->toArray();
 
diff --git a/system/src/Grav/Common/Filesystem/Folder.php b/system/src/Grav/Common/Filesystem/Folder.php
index ec3ac5801..ecbc6ceac 100644
--- a/system/src/Grav/Common/Filesystem/Folder.php
+++ b/system/src/Grav/Common/Filesystem/Folder.php
@@ -197,7 +197,7 @@ abstract class Folder
      * Shift first directory out of the path.
      *
      * @param string $path
-     * @return string
+     * @return string|null
      */
     public static function shift(&$path)
     {
@@ -417,7 +417,8 @@ abstract class Folder
 
         if (!$success) {
             $error = error_get_last();
-            throw new RuntimeException($error['message']);
+
+            throw new RuntimeException($error['message'] ?? 'Unknown error');
         }
 
         // Make sure that the change will be detected when caching.
diff --git a/system/src/Grav/Common/Filesystem/ZipArchiver.php b/system/src/Grav/Common/Filesystem/ZipArchiver.php
index 450a58126..6e53e70a3 100644
--- a/system/src/Grav/Common/Filesystem/ZipArchiver.php
+++ b/system/src/Grav/Common/Filesystem/ZipArchiver.php
@@ -57,7 +57,9 @@ class ZipArchiver extends Archiver
             throw new InvalidArgumentException('ZipArchiver: Zip PHP module not installed...');
         }
 
-        if (!file_exists($source)) {
+        // Get real path for our folder
+        $rootPath = realpath($source);
+        if (!$rootPath) {
             throw new InvalidArgumentException('ZipArchiver: ' . $source . ' cannot be found...');
         }
 
@@ -66,9 +68,6 @@ class ZipArchiver extends Archiver
             throw new InvalidArgumentException('ZipArchiver:' . $this->archive_file . ' cannot be created...');
         }
 
-        // Get real path for our folder
-        $rootPath = realpath($source);
-
         $files = $this->getArchiveFiles($rootPath);
 
         $status && $status([
diff --git a/system/src/Grav/Common/Flex/FlexObject.php b/system/src/Grav/Common/Flex/FlexObject.php
index 66e5412aa..b64aea1df 100644
--- a/system/src/Grav/Common/Flex/FlexObject.php
+++ b/system/src/Grav/Common/Flex/FlexObject.php
@@ -43,7 +43,7 @@ abstract class FlexObject extends \Grav\Framework\Flex\FlexObject implements Med
 
         // Handle media fields.
         $settings = $this->getFieldSettings($name);
-        if ($settings['media_field'] ?? false === true) {
+        if (($settings['media_field'] ?? false) === true) {
             return $this->parseFileProperty($value, $settings);
         }
 
diff --git a/system/src/Grav/Common/Flex/Types/Pages/PageCollection.php b/system/src/Grav/Common/Flex/Types/Pages/PageCollection.php
index 08f192fe7..7503653b8 100644
--- a/system/src/Grav/Common/Flex/Types/Pages/PageCollection.php
+++ b/system/src/Grav/Common/Flex/Types/Pages/PageCollection.php
@@ -19,7 +19,6 @@ use Grav\Common\Page\Header;
 use Grav\Common\Page\Interfaces\PageCollectionInterface;
 use Grav\Common\Page\Interfaces\PageInterface;
 use Grav\Common\Utils;
-use Grav\Framework\Flex\Interfaces\FlexObjectInterface;
 use Grav\Framework\Flex\Pages\FlexPageCollection;
 use Collator;
 use InvalidArgumentException;
@@ -159,7 +158,7 @@ class PageCollection extends FlexPageCollection implements PageCollectionInterfa
      */
     public function addPage(PageInterface $page)
     {
-        if (!$page instanceof FlexObjectInterface) {
+        if (!$page instanceof PageObject) {
             throw new InvalidArgumentException('$page is not a flex page.');
         }
 
@@ -400,8 +399,8 @@ class PageCollection extends FlexPageCollection implements PageCollectionInterfa
             $i = count($manual);
             $new_list = [];
             foreach ($list as $key => $dummy) {
-                $child = $this[$key];
-                $order = array_search($child->slug, $manual, true);
+                $child = $this[$key] ?? null;
+                $order = $child ? array_search($child->slug, $manual, true) : false;
                 if ($order === false) {
                     $order = $i++;
                 }
diff --git a/system/src/Grav/Common/Flex/Types/Pages/PageIndex.php b/system/src/Grav/Common/Flex/Types/Pages/PageIndex.php
index dd06f5868..f02a64866 100644
--- a/system/src/Grav/Common/Flex/Types/Pages/PageIndex.php
+++ b/system/src/Grav/Common/Flex/Types/Pages/PageIndex.php
@@ -109,6 +109,10 @@ class PageIndex extends FlexPageIndex implements PageCollectionInterface
         }
 
         $element = parent::get($key);
+        if (null === $element) {
+            return null;
+        }
+
         if (isset($params)) {
             $element = $element->getTranslation(ltrim($params, '.'));
         }
@@ -331,7 +335,10 @@ class PageIndex extends FlexPageIndex implements PageCollectionInterface
      */
     protected function filterByParent(array $filters)
     {
-        return parent::filterBy($filters);
+        /** @var static $index */
+        $index = parent::filterBy($filters);
+
+        return $index;
     }
 
     /**
@@ -673,12 +680,13 @@ class PageIndex extends FlexPageIndex implements PageCollectionInterface
                     $child_count = $tmp->count();
                     $count = $filters ? $tmp->filterBy($filters, true)->count() : null;
                     $route = $child->getRoute();
+                    $route = $route ? ($route->toString(false) ?: '/') : '';
                     $payload = [
                         'item-key' => htmlspecialchars(basename($child->rawRoute() ?? $child->getKey())),
                         'icon' => $icon,
                         'title' => htmlspecialchars($child->menu()),
                         'route' => [
-                            'display' => htmlspecialchars(($route ? ($route->toString(false) ?: '/') : null) ?? ''),
+                            'display' => htmlspecialchars($route) ?: null,
                             'raw' => htmlspecialchars($child->rawRoute()),
                         ],
                         'modified' => $this->jsDate($child->modified()),
@@ -834,12 +842,11 @@ class PageIndex extends FlexPageIndex implements PageCollectionInterface
     /**
      * Remove item from the list.
      *
-     * @param PageInterface|string|null $key
-     *
-     * @return $this
+     * @param string $key
+     * @return PageObject|null
      * @throws InvalidArgumentException
      */
-    public function remove($key = null)
+    public function remove($key)
     {
         return $this->getCollection()->remove($key);
     }
diff --git a/system/src/Grav/Common/Flex/Types/Pages/PageObject.php b/system/src/Grav/Common/Flex/Types/Pages/PageObject.php
index 5ad456b77..4c83f959b 100644
--- a/system/src/Grav/Common/Flex/Types/Pages/PageObject.php
+++ b/system/src/Grav/Common/Flex/Types/Pages/PageObject.php
@@ -104,12 +104,12 @@ class PageObject extends FlexPageObject
      */
     public function getRoute($query = []): ?Route
     {
-        $route = $this->route();
-        if (null === $route) {
+        $path = $this->route();
+        if (null === $path) {
             return null;
         }
 
-        $route = RouteFactory::createFromString($route);
+        $route = RouteFactory::createFromString($path);
         if ($lang = $route->getLanguage()) {
             $grav = Grav::instance();
             if (!$grav['config']->get('system.languages.include_default_lang')) {
@@ -441,7 +441,8 @@ class PageObject extends FlexPageObject
 
         // Add missing siblings into the end of the list, keeping the previous ordering between them.
         foreach ($siblings as $sibling) {
-            $basename = preg_replace('|^\d+\.|', '', $sibling->getProperty('folder'));
+            $folder = (string)$sibling->getProperty('folder');
+            $basename = preg_replace('|^\d+\.|', '', $folder);
             if (!in_array($basename, $ordering, true)) {
                 $ordering[] = $basename;
             }
@@ -451,7 +452,8 @@ class PageObject extends FlexPageObject
         $ordering = array_flip(array_values($ordering));
         $count = count($ordering);
         foreach ($siblings as $sibling) {
-            $basename = preg_replace('|^\d+\.|', '', $sibling->getProperty('folder'));
+            $folder = (string)$sibling->getProperty('folder');
+            $basename = preg_replace('|^\d+\.|', '', $folder);
             $newOrder = $ordering[$basename] ?? null;
             $newOrder = null !== $newOrder ? $newOrder + 1 : (int)$sibling->order() + $count;
             $sibling->order($newOrder);
diff --git a/system/src/Grav/Common/Flex/Types/Pages/Traits/PageLegacyTrait.php b/system/src/Grav/Common/Flex/Types/Pages/Traits/PageLegacyTrait.php
index d8193df7c..589ea881a 100644
--- a/system/src/Grav/Common/Flex/Types/Pages/Traits/PageLegacyTrait.php
+++ b/system/src/Grav/Common/Flex/Types/Pages/Traits/PageLegacyTrait.php
@@ -103,7 +103,10 @@ trait PageLegacyTrait
         $parent = $this->parent();
         $collection = $parent ? $parent->collection('content', false) : null;
         if (null !== $path && $collection instanceof PageCollectionInterface) {
-            return $collection->adjacentSibling($path, $direction);
+            $child = $collection->adjacentSibling($path, $direction);
+            if ($child instanceof PageInterface) {
+                return $child;
+            }
         }
 
         return false;
diff --git a/system/src/Grav/Common/Flex/Types/Users/UserCollection.php b/system/src/Grav/Common/Flex/Types/Users/UserCollection.php
index e17525a9c..9b6490a8a 100644
--- a/system/src/Grav/Common/Flex/Types/Users/UserCollection.php
+++ b/system/src/Grav/Common/Flex/Types/Users/UserCollection.php
@@ -92,7 +92,7 @@ class UserCollection extends FlexCollection implements UserCollectionInterface
                 } else {
                     $user = parent::find($query, $field);
                 }
-                if ($user) {
+                if ($user instanceof UserObject) {
                     return $user;
                 }
             }
@@ -123,7 +123,7 @@ class UserCollection extends FlexCollection implements UserCollectionInterface
      * @param string $key
      * @return string
      */
-    protected function filterUsername(string $key)
+    protected function filterUsername(string $key): string
     {
         $storage = $this->getFlexDirectory()->getStorage();
         if (method_exists($storage, 'normalizeKey')) {
diff --git a/system/src/Grav/Common/Flex/Types/Users/UserIndex.php b/system/src/Grav/Common/Flex/Types/Users/UserIndex.php
index 4a3f58773..6e0bc65fe 100644
--- a/system/src/Grav/Common/Flex/Types/Users/UserIndex.php
+++ b/system/src/Grav/Common/Flex/Types/Users/UserIndex.php
@@ -62,7 +62,7 @@ class UserIndex extends FlexIndex implements UserCollectionInterface
      * @param FlexStorageInterface $storage
      * @return void
      */
-    public static function updateObjectMeta(array &$meta, array $data, FlexStorageInterface $storage)
+    public static function updateObjectMeta(array &$meta, array $data, FlexStorageInterface $storage): void
     {
         // Username can also be number and stored as such.
         $key = (string)($data['username'] ?? $meta['key'] ?? $meta['storage_key']);
@@ -187,7 +187,7 @@ class UserIndex extends FlexIndex implements UserCollectionInterface
      * @param array $updated
      * @param array $removed
      */
-    protected static function onChanges(array $entries, array $added, array $updated, array $removed)
+    protected static function onChanges(array $entries, array $added, array $updated, array $removed): void
     {
         $message = sprintf('Flex: User index updated, %d objects (%d added, %d updated, %d removed).', count($entries), count($added), count($updated), count($removed));
 
diff --git a/system/src/Grav/Common/Grav.php b/system/src/Grav/Common/Grav.php
index ffbb50818..f5919613b 100644
--- a/system/src/Grav/Common/Grav.php
+++ b/system/src/Grav/Common/Grav.php
@@ -135,7 +135,7 @@ class Grav extends Container
      *
      * @return void
      */
-    public static function resetInstance()
+    public static function resetInstance(): void
     {
         if (self::$instance) {
             // @phpstan-ignore-next-line
@@ -242,7 +242,7 @@ class Grav extends Container
      *
      * @return void
      */
-    public function process()
+    public function process(): void
     {
         if (isset($this->initialized['process'])) {
             return;
@@ -474,7 +474,7 @@ class Grav extends Container
      * @param int    $code  Redirection code (30x)
      * @return void
      */
-    public function redirectLangSafe($route, $code = null)
+    public function redirectLangSafe($route, $code = null): void
     {
         if (!$this['uri']->isExternal($route)) {
             $this->redirect($this['pages']->route($route), $code);
@@ -489,7 +489,7 @@ class Grav extends Container
      * @param ResponseInterface|null $response
      * @return void
      */
-    public function header(ResponseInterface $response = null)
+    public function header(ResponseInterface $response = null): void
     {
         if (null === $response) {
             /** @var PageInterface $page */
@@ -514,7 +514,7 @@ class Grav extends Container
      *
      * @return void
      */
-    public function setLocale()
+    public function setLocale(): void
     {
         // Initialize Locale if set and configured.
         if ($this['language']->enabled() && $this['config']->get('system.languages.override_locale')) {
@@ -575,7 +575,7 @@ class Grav extends Container
      *
      * @return void
      */
-    public function shutdown()
+    public function shutdown(): void
     {
         // Prevent user abort allowing onShutdown event to run without interruptions.
         if (function_exists('ignore_user_abort')) {
@@ -694,7 +694,7 @@ class Grav extends Container
      *
      * @return void
      */
-    protected function registerServices()
+    protected function registerServices(): void
     {
         foreach (self::$diMap as $serviceKey => $serviceClass) {
             if (is_int($serviceKey)) {
@@ -761,12 +761,10 @@ class Grav extends Container
             // unsupported media type, try to download it...
             if ($uri_extension) {
                 $extension = $uri_extension;
+            } elseif (isset($path_parts['extension'])) {
+                $extension = $path_parts['extension'];
             } else {
-                if (isset($path_parts['extension'])) {
-                    $extension = $path_parts['extension'];
-                } else {
-                    $extension = null;
-                }
+                $extension = null;
             }
 
             if ($extension) {
@@ -781,6 +779,6 @@ class Grav extends Container
             return false;
         }
 
-        return $page;
+        return $page ?? false;
     }
 }
diff --git a/system/src/Grav/Common/Helpers/Excerpts.php b/system/src/Grav/Common/Helpers/Excerpts.php
index cd285cf87..173850a53 100644
--- a/system/src/Grav/Common/Helpers/Excerpts.php
+++ b/system/src/Grav/Common/Helpers/Excerpts.php
@@ -33,6 +33,9 @@ class Excerpts
     public static function processImageHtml($html, PageInterface $page = null)
     {
         $excerpt = static::getExcerptFromHtml($html, 'img');
+        if (null === $excerpt) {
+            return '';
+        }
 
         $original_src = $excerpt['element']['attributes']['src'];
         $excerpt['element']['attributes']['href'] = $original_src;
@@ -61,6 +64,9 @@ class Excerpts
     public static function processLinkHtml($html, PageInterface $page = null)
     {
         $excerpt = static::getExcerptFromHtml($html, 'a');
+        if (null === $excerpt) {
+            return '';
+        }
 
         $original_href = $excerpt['element']['attributes']['href'];
         $excerpt = static::processLinkExcerpt($excerpt, $page, 'link');
@@ -89,7 +95,6 @@ class Excerpts
         $excerpt = null;
         $inner = [];
 
-        /** @var DOMElement $element */
         foreach ($elements as $element) {
             $attributes = [];
             foreach ($element->attributes as $name => $value) {
diff --git a/system/src/Grav/Common/Helpers/LogViewer.php b/system/src/Grav/Common/Helpers/LogViewer.php
index a03fde810..187828ae3 100644
--- a/system/src/Grav/Common/Helpers/LogViewer.php
+++ b/system/src/Grav/Common/Helpers/LogViewer.php
@@ -53,7 +53,6 @@ class LogViewer
      */
     public function tail($filepath, $lines = 1)
     {
-
         $f = $filepath ? @fopen($filepath, 'rb') : false;
         if ($f === false) {
             return false;
@@ -62,13 +61,12 @@ class LogViewer
         $buffer = ($lines < 2 ? 64 : ($lines < 10 ? 512 : 4096));
 
         fseek($f, -1, SEEK_END);
-        if (fread($f, 1) != "\n") {
-            $lines -= 1;
+        if (fread($f, 1) !== "\n") {
+            --$lines;
         }
 
         // Start reading
         $output = '';
-        $chunk = '';
         // While we would like more
         while (ftell($f) > 0 && $lines >= 0) {
             // Figure out how far back we should jump
@@ -76,7 +74,11 @@ class LogViewer
             // Do the jump (backwards, relative to where we are)
             fseek($f, -$seek, SEEK_CUR);
             // Read a chunk and prepend it to our output
-            $output = ($chunk = fread($f, $seek)) . $output;
+            $chunk = fread($f, $seek);
+            if ($chunk === false) {
+                throw new \RuntimeException('Cannot read file');
+            }
+            $output = $chunk . $output;
             // Jump back to where we started reading
             fseek($f, -mb_strlen($chunk, '8bit'), SEEK_CUR);
             // Decrease our line counter
@@ -123,13 +125,13 @@ class LogViewer
      */
     public function parse($line)
     {
-        if (!is_string($line) || strlen($line) === 0) {
-            return array();
+        if (!is_string($line) || $line === '') {
+            return [];
         }
 
         preg_match($this->pattern, $line, $data);
         if (!isset($data['date'])) {
-            return array();
+            return [];
         }
 
         preg_match('/(.*)- Trace:(.*)/', $data['message'], $matches);
@@ -138,7 +140,7 @@ class LogViewer
             $data['trace'] = trim($matches[2]);
         }
 
-        return array(
+        return [
             'date' => DateTime::createFromFormat('Y-m-d H:i:s', $data['date']),
             'logger' => $data['logger'],
             'level' => $data['level'],
@@ -146,7 +148,7 @@ class LogViewer
             'trace' => isset($data['trace']) ? $this->parseTrace($data['trace']) : null,
             'context' => json_decode($data['context'], true),
             'extra' => json_decode($data['extra'], true)
-        );
+        ];
     }
 
     /**
diff --git a/system/src/Grav/Common/Iterator.php b/system/src/Grav/Common/Iterator.php
index cc7cf9286..6e80b947e 100644
--- a/system/src/Grav/Common/Iterator.php
+++ b/system/src/Grav/Common/Iterator.php
@@ -230,9 +230,7 @@ class Iterator implements \ArrayAccess, \Iterator, \Countable, \Serializable
     public function filter(callable $callback = null)
     {
         foreach ($this->items as $key => $value) {
-            if ((!$callback && !(bool)$value) ||
-                ($callback && !$callback($value, $key))
-            ) {
+            if ((!$callback && !(bool)$value) || ($callback && !$callback($value, $key))) {
                 unset($this->items[$key]);
             }
         }
diff --git a/system/src/Grav/Common/Language/LanguageCodes.php b/system/src/Grav/Common/Language/LanguageCodes.php
index 9282070d6..f0a35322d 100644
--- a/system/src/Grav/Common/Language/LanguageCodes.php
+++ b/system/src/Grav/Common/Language/LanguageCodes.php
@@ -187,12 +187,7 @@ class LanguageCodes
      */
     public static function getOrientation($code)
     {
-        if (isset(static::$codes[$code])) {
-            if (isset(static::$codes[$code]['orientation'])) {
-                return static::get($code, 'orientation');
-            }
-        }
-        return 'ltr';
+        return static::$codes[$code]['orientation'] ?? 'ltr';
     }
 
     /**
@@ -226,11 +221,7 @@ class LanguageCodes
      */
     public static function get($code, $type)
     {
-        if (isset(static::$codes[$code][$type])) {
-            return static::$codes[$code][$type];
-        }
-
-        return false;
+        return static::$codes[$code][$type] ?? false;
     }
 
     /**
diff --git a/system/src/Grav/Common/Page/Collection.php b/system/src/Grav/Common/Page/Collection.php
index c9a3cdbd5..32b917cd2 100644
--- a/system/src/Grav/Common/Page/Collection.php
+++ b/system/src/Grav/Common/Page/Collection.php
@@ -47,7 +47,7 @@ class Collection extends Iterator implements PageCollectionInterface
         parent::__construct($items);
 
         $this->params = $params;
-        $this->pages = $pages ? $pages : Grav::instance()->offsetGet('pages');
+        $this->pages = $pages ?: Grav::instance()->offsetGet('pages');
     }
 
     /**
diff --git a/system/src/Grav/Common/Page/Page.php b/system/src/Grav/Common/Page/Page.php
index a0356134c..2099be212 100644
--- a/system/src/Grav/Common/Page/Page.php
+++ b/system/src/Grav/Common/Page/Page.php
@@ -2274,11 +2274,11 @@ class Page implements PageInterface
     {
         if ($var !== null) {
             // make sure first level are arrays
-            array_walk($var, function (&$value) {
+            array_walk($var, static function (&$value) {
                 $value = (array) $value;
             });
             // make sure all values are strings
-            array_walk_recursive($var, function (&$value) {
+            array_walk_recursive($var, static function (&$value) {
                 $value = (string) $value;
             });
             $this->taxonomy = $var;
diff --git a/system/src/Grav/Common/Page/Pages.php b/system/src/Grav/Common/Page/Pages.php
index c5e08e45a..941c9a7b3 100644
--- a/system/src/Grav/Common/Page/Pages.php
+++ b/system/src/Grav/Common/Page/Pages.php
@@ -326,7 +326,7 @@ class Pages
      *
      * @return void
      */
-    public function reset()
+    public function reset(): void
     {
         $this->initialized = false;
 
@@ -606,7 +606,7 @@ class Pages
 
             if (is_array($sort_flags)) {
                 $sort_flags = array_map('constant', $sort_flags); //transform strings to constant value
-                $sort_flags = array_reduce($sort_flags, function ($a, $b) {
+                $sort_flags = array_reduce($sort_flags, static function ($a, $b) {
                     return $a | $b;
                 }, 0); //merge constant values using bit or
             }
@@ -715,29 +715,39 @@ class Pages
 
         switch ($type) {
             case 'all':
-                return $page->children();
+                $collection = $page->children();
+                break;
             case 'modules':
             case 'modular':
-                return $page->children()->modules();
+                $collection = $page->children()->modules();
+                break;
             case 'pages':
             case 'children':
-                return $page->children()->pages();
+                $collection = $page->children()->pages();
+                break;
             case 'page':
             case 'self':
-                return !$page->root() ? (new Collection())->addPage($page) : new Collection();
+                $collection = !$page->root() ? (new Collection())->addPage($page) : new Collection();
+                break;
             case 'parent':
                 $parent = $page->parent();
                 $collection = new Collection();
-                return $parent ? $collection->addPage($parent) : $collection;
+                $collection = $parent ? $collection->addPage($parent) : $collection;
+                break;
             case 'siblings':
                 $parent = $page->parent();
-                return $parent ? $parent->children()->remove($page->path()) : new Collection();
+                $collection = $parent ? $parent->children()->remove($page->path()) : new Collection();
+                break;
             case 'descendants':
-                return $this->all($page)->remove($page->path())->pages();
+                $collection = $this->all($page)->remove($page->path())->pages();
+                break;
             default:
                 // Unknown type; return empty collection.
-                return new Collection();
+                $collection = new Collection();
+                break;
         }
+
+        return $collection;
     }
 
     /**
@@ -1813,7 +1823,7 @@ class Pages
         // Build regular expression for all the allowed page extensions.
         $page_extensions = $language->getFallbackPageExtensions();
         $regex = '/^[^\.]*(' . implode('|', array_map(
-            function ($str) {
+            static function ($str) {
                 return preg_quote($str, '/');
             },
             $page_extensions
diff --git a/system/src/Grav/Common/Scheduler/Job.php b/system/src/Grav/Common/Scheduler/Job.php
index 94fbaf102..13059a572 100644
--- a/system/src/Grav/Common/Scheduler/Job.php
+++ b/system/src/Grav/Common/Scheduler/Job.php
@@ -271,7 +271,7 @@ class Job
         if ($whenOverlapping) {
             $this->whenOverlapping = $whenOverlapping;
         } else {
-            $this->whenOverlapping = function () {
+            $this->whenOverlapping = static function () {
                 return false;
             };
         }
diff --git a/system/src/Grav/Common/Security.php b/system/src/Grav/Common/Security.php
index 50d9a5d46..833e64808 100644
--- a/system/src/Grav/Common/Security.php
+++ b/system/src/Grav/Common/Security.php
@@ -107,7 +107,7 @@ class Security
                 $content = $page->value('content');
 
                 $data = ['header' => $header, 'content' => $content];
-                $results = Security::detectXssFromArray($data);
+                $results = static::detectXssFromArray($data);
 
                 if (!empty($results)) {
                     if ($route) {
@@ -199,7 +199,7 @@ class Security
         $string = urldecode($string);
 
         // Convert Hexadecimals
-        $string = (string)preg_replace_callback('!(&#|\\\)[xX]([0-9a-fA-F]+);?!u', function ($m) {
+        $string = (string)preg_replace_callback('!(&#|\\\)[xX]([0-9a-fA-F]+);?!u', static function ($m) {
             return chr(hexdec($m[2]));
         }, $string);
 
@@ -239,7 +239,7 @@ class Security
             }
         }
 
-        return false;
+        return null;
     }
 
     public static function getXssDefaults(): array
diff --git a/system/src/Grav/Common/Session.php b/system/src/Grav/Common/Session.php
index 2dbc3073a..322162705 100644
--- a/system/src/Grav/Common/Session.php
+++ b/system/src/Grav/Common/Session.php
@@ -129,12 +129,12 @@ class Session extends \Grav\Framework\Session\Session
                 /** @var Uri $uri */
                 $uri = $grav['uri'];
                 /** @var Forms|null $form */
-                $form = $grav['forms']->getActiveForm(); // @phpstan-ignore-line
+                $form = $grav['forms']->getActiveForm(); // @phpstan-ignore-line (form plugin)
 
                 $sessionField = base64_encode($uri->url);
 
                 /** @var FormFlash|null $flash */
-                $flash = $form ? $form->getFlash() : null; // @phpstan-ignore-line
+                $flash = $form ? $form->getFlash() : null; // @phpstan-ignore-line (form plugin)
                 $object = $flash && method_exists($flash, 'getLegacyFiles') ? [$sessionField => $flash->getLegacyFiles()] : null;
             }
         }
diff --git a/system/src/Grav/Common/Taxonomy.php b/system/src/Grav/Common/Taxonomy.php
index de3c4526c..0d0a450b0 100644
--- a/system/src/Grav/Common/Taxonomy.php
+++ b/system/src/Grav/Common/Taxonomy.php
@@ -105,7 +105,7 @@ class Taxonomy
             }
         } elseif (is_string($value)) {
             if (!empty($key)) {
-                $taxonomy = $taxonomy . $key;
+                $taxonomy .= $key;
             }
             $this->taxonomy_map[$taxonomy][(string) $value][$page->path()] = ['slug' => $page->slug()];
         }
diff --git a/system/src/Grav/Common/Utils.php b/system/src/Grav/Common/Utils.php
index 34b6e0f13..f843a0c66 100644
--- a/system/src/Grav/Common/Utils.php
+++ b/system/src/Grav/Common/Utils.php
@@ -166,9 +166,9 @@ abstract class Utils
 
         if ($locator->isStream($path)) {
             $path = $locator->findResource($path, true);
-        } elseif (!Utils::startsWith($path, GRAV_ROOT)) {
+        } elseif (!static::startsWith($path, GRAV_ROOT)) {
             $base_url = Grav::instance()['base_url'];
-            $path = GRAV_ROOT . '/' . ltrim(Utils::replaceFirstOccurrence($base_url, '', $path), '/');
+            $path = GRAV_ROOT . '/' . ltrim(static::replaceFirstOccurrence($base_url, '', $path), '/');
         }
 
         return $path;
@@ -767,13 +767,13 @@ abstract class Utils
         if (is_string($http_accept)) {
             $negotiator = new Negotiator();
 
-            $supported_types = Utils::getSupportPageTypes(['html', 'json']);
-            $priorities = Utils::getMimeTypes($supported_types);
+            $supported_types = static::getSupportPageTypes(['html', 'json']);
+            $priorities = static::getMimeTypes($supported_types);
 
             $media_type = $negotiator->getBest($http_accept, $priorities);
             $mimetype = $media_type instanceof Accept ? $media_type->getValue() : '';
 
-            return Utils::getExtensionByMime($mimetype);
+            return static::getExtensionByMime($mimetype);
         }
 
         return 'html';
@@ -808,13 +808,7 @@ abstract class Utils
 
         $media_types = Grav::instance()['config']->get('media.types');
 
-        if (isset($media_types[$extension])) {
-            if (isset($media_types[$extension]['mime'])) {
-                return $media_types[$extension]['mime'];
-            }
-        }
-
-        return $default;
+        return $media_types[$extension]['mime'] ?? $default;
     }
 
     /**
@@ -1756,7 +1750,7 @@ abstract class Utils
     {
         $enc_url = preg_replace_callback(
             '%[^:/@?&=#]+%usD',
-            function ($matches) {
+            static function ($matches) {
                 return urlencode($matches[0]);
             },
             $url