diff --git a/src/Laravel/Command/InstallCommand.php b/src/Laravel/Command/InstallCommand.php
index 3ec65969..d69e4db4 100644
--- a/src/Laravel/Command/InstallCommand.php
+++ b/src/Laravel/Command/InstallCommand.php
@@ -119,7 +119,7 @@ final class InstallCommand extends Command
             $output->writeln('<bg=red;options=bold> ERROR </> An error occurred during the installation of <fg=blue;options=bold>PHPFlasher</> resources.');
         }
 
-        $this->assetManager->createManifest(array_merge([], ...$files));
+        $this->assetManager->createManifest(array_merge(...$files));
 
         $output->writeln('');
 
diff --git a/src/Prime/Plugin/FlasherPlugin.php b/src/Prime/Plugin/FlasherPlugin.php
index d4278658..d39c4f49 100644
--- a/src/Prime/Plugin/FlasherPlugin.php
+++ b/src/Prime/Plugin/FlasherPlugin.php
@@ -397,6 +397,25 @@ final class FlasherPlugin extends Plugin
         return $config;
     }
 
+    private const DEFAULT_THEME_NAMES = [
+        'amazon',
+        'amber',
+        'jade',
+        'crystal',
+        'emerald',
+        'sapphire',
+        'ruby',
+        'onyx',
+        'neon',
+        'aurora',
+        'minimal',
+        'material',
+        'google',
+        'ios',
+        'slack',
+        'facebook',
+    ];
+
     /**
      * @return array<string, array{
      *     scripts: string[],
@@ -406,135 +425,19 @@ final class FlasherPlugin extends Plugin
      */
     private function getDefaultThemes(): array
     {
-        return [
-            'amazon' => [
-                'scripts' => ['/vendor/flasher/themes/amazon/amazon.min.js'],
+        $themes = [];
+
+        foreach (self::DEFAULT_THEME_NAMES as $name) {
+            $themes[$name] = [
+                'scripts' => ["/vendor/flasher/themes/{$name}/{$name}.min.js"],
                 'styles' => [
                     '/vendor/flasher/flasher.min.css',
-                    '/vendor/flasher/themes/amazon/amazon.min.css',
+                    "/vendor/flasher/themes/{$name}/{$name}.min.css",
                 ],
                 'options' => [],
-            ],
-            'amber' => [
-                'scripts' => ['/vendor/flasher/themes/amber/amber.min.js'],
-                'styles' => [
-                    '/vendor/flasher/flasher.min.css',
-                    '/vendor/flasher/themes/amber/amber.min.css',
-                ],
-                'options' => [],
-            ],
-            'jade' => [
-                'scripts' => ['/vendor/flasher/themes/jade/jade.min.js'],
-                'styles' => [
-                    '/vendor/flasher/flasher.min.css',
-                    '/vendor/flasher/themes/jade/jade.min.css',
-                ],
-                'options' => [],
-            ],
-            'crystal' => [
-                'scripts' => ['/vendor/flasher/themes/crystal/crystal.min.js'],
-                'styles' => [
-                    '/vendor/flasher/flasher.min.css',
-                    '/vendor/flasher/themes/crystal/crystal.min.css',
-                ],
-                'options' => [],
-            ],
-            'emerald' => [
-                'scripts' => ['/vendor/flasher/themes/emerald/emerald.min.js'],
-                'styles' => [
-                    '/vendor/flasher/flasher.min.css',
-                    '/vendor/flasher/themes/emerald/emerald.min.css',
-                ],
-                'options' => [],
-            ],
-            'sapphire' => [
-                'scripts' => ['/vendor/flasher/themes/sapphire/sapphire.min.js'],
-                'styles' => [
-                    '/vendor/flasher/flasher.min.css',
-                    '/vendor/flasher/themes/sapphire/sapphire.min.css',
-                ],
-                'options' => [],
-            ],
-            'ruby' => [
-                'scripts' => ['/vendor/flasher/themes/ruby/ruby.min.js'],
-                'styles' => [
-                    '/vendor/flasher/flasher.min.css',
-                    '/vendor/flasher/themes/ruby/ruby.min.css',
-                ],
-                'options' => [],
-            ],
-            'onyx' => [
-                'scripts' => ['/vendor/flasher/themes/onyx/onyx.min.js'],
-                'styles' => [
-                    '/vendor/flasher/flasher.min.css',
-                    '/vendor/flasher/themes/onyx/onyx.min.css',
-                ],
-                'options' => [],
-            ],
-            'neon' => [
-                'scripts' => ['/vendor/flasher/themes/neon/neon.min.js'],
-                'styles' => [
-                    '/vendor/flasher/flasher.min.css',
-                    '/vendor/flasher/themes/neon/neon.min.css',
-                ],
-                'options' => [],
-            ],
-            'aurora' => [
-                'scripts' => ['/vendor/flasher/themes/aurora/aurora.min.js'],
-                'styles' => [
-                    '/vendor/flasher/flasher.min.css',
-                    '/vendor/flasher/themes/aurora/aurora.min.css',
-                ],
-                'options' => [],
-            ],
-            'minimal' => [
-                'scripts' => ['/vendor/flasher/themes/minimal/minimal.min.js'],
-                'styles' => [
-                    '/vendor/flasher/flasher.min.css',
-                    '/vendor/flasher/themes/minimal/minimal.min.css',
-                ],
-                'options' => [],
-            ],
-            'material' => [
-                'scripts' => ['/vendor/flasher/themes/material/material.min.js'],
-                'styles' => [
-                    '/vendor/flasher/flasher.min.css',
-                    '/vendor/flasher/themes/material/material.min.css',
-                ],
-                'options' => [],
-            ],
-            'google' => [
-                'scripts' => ['/vendor/flasher/themes/google/google.min.js'],
-                'styles' => [
-                    '/vendor/flasher/flasher.min.css',
-                    '/vendor/flasher/themes/google/google.min.css',
-                ],
-                'options' => [],
-            ],
-            'ios' => [
-                'scripts' => ['/vendor/flasher/themes/ios/ios.min.js'],
-                'styles' => [
-                    '/vendor/flasher/flasher.min.css',
-                    '/vendor/flasher/themes/ios/ios.min.css',
-                ],
-                'options' => [],
-            ],
-            'slack' => [
-                'scripts' => ['/vendor/flasher/themes/slack/slack.min.js'],
-                'styles' => [
-                    '/vendor/flasher/flasher.min.css',
-                    '/vendor/flasher/themes/slack/slack.min.css',
-                ],
-                'options' => [],
-            ],
-            'facebook' => [
-                'scripts' => ['/vendor/flasher/themes/facebook/facebook.min.js'],
-                'styles' => [
-                    '/vendor/flasher/flasher.min.css',
-                    '/vendor/flasher/themes/facebook/facebook.min.css',
-                ],
-                'options' => [],
-            ],
-        ];
+            ];
+        }
+
+        return $themes;
     }
 }
diff --git a/src/Prime/Storage/Filter/Criteria/FilterCriteria.php b/src/Prime/Storage/Filter/Criteria/FilterCriteria.php
index 9d2125bf..0558adfb 100644
--- a/src/Prime/Storage/Filter/Criteria/FilterCriteria.php
+++ b/src/Prime/Storage/Filter/Criteria/FilterCriteria.php
@@ -36,11 +36,23 @@ final class FilterCriteria implements CriteriaInterface
      * @param Envelope[] $envelopes
      *
      * @return Envelope[]
+     *
+     * @throws \InvalidArgumentException
      */
     public function apply(array $envelopes): array
     {
         foreach ($this->callbacks as $callback) {
-            $envelopes = $callback($envelopes);
+            $result = $callback($envelopes);
+
+            if (!\is_array($result)) {
+                throw new \InvalidArgumentException(\sprintf(
+                    'Filter callback must return an array, got "%s".',
+                    get_debug_type($result)
+                ));
+            }
+
+            /** @var Envelope[] $result */
+            $envelopes = $result;
         }
 
         return $envelopes;
diff --git a/src/SweetAlert/Prime/SweetAlertBuilder.php b/src/SweetAlert/Prime/SweetAlertBuilder.php
index 58b905af..7f98131e 100644
--- a/src/SweetAlert/Prime/SweetAlertBuilder.php
+++ b/src/SweetAlert/Prime/SweetAlertBuilder.php
@@ -152,7 +152,7 @@ final class SweetAlertBuilder extends NotificationBuilder
     }
 
     /**
-     * @phpstan-param array<string, mixed> $options
+     * @phpstan-param OptionsType $options
      */
     public function question(?string $message = null, array $options = []): self
     {
@@ -162,7 +162,7 @@ final class SweetAlertBuilder extends NotificationBuilder
             $this->messages($message);
         }
 
-        if ([] === $options) {
+        if ([] !== $options) {
             $this->options($options);
         }
 
@@ -229,8 +229,9 @@ final class SweetAlertBuilder extends NotificationBuilder
 
     public function showClass(string $showClass, string $value): self
     {
+        /** @var array<string, string> $option */
         $option = $this->getEnvelope()->getOption('showClass', []);
-        $option[$showClass] = $value; // @phpstan-ignore-line
+        $option[$showClass] = $value;
 
         $this->option('showClass', $option);
 
@@ -239,8 +240,9 @@ final class SweetAlertBuilder extends NotificationBuilder
 
     public function hideClass(string $hideClass, string $value): self
     {
+        /** @var array<string, string> $option */
         $option = $this->getEnvelope()->getOption('hideClass', []);
-        $option[$hideClass] = $value; // @phpstan-ignore-line
+        $option[$hideClass] = $value;
 
         $this->option('hideClass', $option);
 
diff --git a/src/Symfony/Command/InstallCommand.php b/src/Symfony/Command/InstallCommand.php
index 7ad392f0..849d1f25 100644
--- a/src/Symfony/Command/InstallCommand.php
+++ b/src/Symfony/Command/InstallCommand.php
@@ -134,7 +134,7 @@ final class InstallCommand extends Command
         }
 
         // Create asset manifest
-        $this->assetManager->createManifest(array_merge([], ...$files));
+        $this->assetManager->createManifest(array_merge(...$files));
 
         $output->writeln('');
 
diff --git a/tests/Prime/Storage/Filter/Criteria/FilterCriteriaTest.php b/tests/Prime/Storage/Filter/Criteria/FilterCriteriaTest.php
index 0d7ecf23..1830c15f 100644
--- a/tests/Prime/Storage/Filter/Criteria/FilterCriteriaTest.php
+++ b/tests/Prime/Storage/Filter/Criteria/FilterCriteriaTest.php
@@ -194,4 +194,34 @@ final class FilterCriteriaTest extends TestCase
         $this->assertCount(1, $result);
         $this->assertSame('test', $result[0]->getMessage());
     }
+
+    public function testApplyThrowsExceptionWhenCallbackReturnsNonArray(): void
+    {
+        $criteria = new FilterCriteria(fn ($e) => 'not an array');
+
+        $this->expectException(\InvalidArgumentException::class);
+        $this->expectExceptionMessage('Filter callback must return an array, got "string".');
+
+        $criteria->apply([new Envelope(new Notification())]);
+    }
+
+    public function testApplyThrowsExceptionWhenCallbackReturnsNull(): void
+    {
+        $criteria = new FilterCriteria(fn ($e) => null);
+
+        $this->expectException(\InvalidArgumentException::class);
+        $this->expectExceptionMessage('Filter callback must return an array, got "null".');
+
+        $criteria->apply([new Envelope(new Notification())]);
+    }
+
+    public function testApplyThrowsExceptionWhenCallbackReturnsObject(): void
+    {
+        $criteria = new FilterCriteria(fn ($e) => new \stdClass());
+
+        $this->expectException(\InvalidArgumentException::class);
+        $this->expectExceptionMessage('Filter callback must return an array, got "stdClass".');
+
+        $criteria->apply([new Envelope(new Notification())]);
+    }
 }
diff --git a/tests/SweetAlert/Prime/SweetAlertBuilderTest.php b/tests/SweetAlert/Prime/SweetAlertBuilderTest.php
index 238835b3..6fb4ced1 100644
--- a/tests/SweetAlert/Prime/SweetAlertBuilderTest.php
+++ b/tests/SweetAlert/Prime/SweetAlertBuilderTest.php
@@ -29,7 +29,7 @@ final class SweetAlertBuilderTest extends TestCase
         $envelope = $this->sweetAlertBuilder->getEnvelope();
         $options = $envelope->getNotification()->getOptions();
 
-        $this->assertSame(['showCancelButton' => true, 'text' => 'Are you sure?'], $options);
+        $this->assertSame(['showCancelButton' => true, 'text' => 'Are you sure?', 'option1' => 'value1'], $options);
     }
 
     public function testTitle(): void