diff --git a/functionMap.php b/functionMap.php
index afacc3c..b88e288 100644
--- a/functionMap.php
+++ b/functionMap.php
@@ -167,4 +167,5 @@
     'wp_get_post_terms' => ["(\$args is array{fields: 'names'|'slugs'} ? list<string> : (\$args is array{fields: 'id=>name'|'id=>slug'} ? array<int, string> : (\$args is array{fields: 'id=>parent'} ? array<int, int> : (\$args is array{fields: 'ids'|'tt_ids'} ? list<int> : array<int, \WP_Term>))))|\WP_Error"],
     'wp_get_object_terms' => ["(\$args is array{fields: 'names'|'slugs'} ? list<string> : (\$args is array{fields: 'id=>name'|'id=>slug'} ? array<int, string> : (\$args is array{fields: 'id=>parent'} ? array<int, int> : (\$args is array{fields: 'ids'|'tt_ids'} ? list<int> : array<int, \WP_Term>))))|\WP_Error"],
     'wp_parse_str' => [null, '@param-out' => 'array<int|string, array|string> $result'],
+    'wp_parse_str' => [null, '@phpstan-param-out' => 'array<int|string, array|string> $result'],
 ];
diff --git a/phpcs.xml.dist b/phpcs.xml.dist
index 749a233..6ebf26a 100644
--- a/phpcs.xml.dist
+++ b/phpcs.xml.dist
@@ -4,6 +4,7 @@
     <file>functionMap.php</file>
     <file>src/</file>
     <file>visitor.php</file>
+    <file>tests/</file>
 
     <rule ref="PSR12NeutronRuleset">
         <exclude name="Generic.Files.LineLength"/>
@@ -11,4 +12,39 @@
         <exclude name="PEAR.Commenting.FileComment"/>
     </rule>
 
+    <!-- Rules not applied to tests -->
+    <rule ref="PSR12NeutronRuleset.NamingConventions.MeaningfulVariableName">
+        <exclude-pattern>tests/</exclude-pattern>
+    </rule>
+    <rule ref="PSR12NeutronRuleset.Strings.ConcatenationUsage">
+        <exclude-pattern>tests/</exclude-pattern>
+    </rule>
+    <rule ref="SlevomatCodingStandard.Namespaces.FullyQualifiedExceptions">
+        <properties>
+            <property name="ignoredNames" type="array">
+                <element value="WP_Error"/>
+            </property>
+        </properties>
+    </rule>
+    <rule ref="SlevomatCodingStandard.PHP.RequireExplicitAssertion">
+        <exclude-pattern>tests/</exclude-pattern>
+    </rule>
+    <rule ref="Squiz.PHP.CommentedOutCode">
+        <exclude-pattern>tests/</exclude-pattern>
+    </rule>
+    <rule ref="WordPress.DateTime.CurrentTimeTimestamp">
+        <exclude-pattern>tests/</exclude-pattern>
+    </rule>
+    <rule ref="WordPress.DB.PreparedSQL">
+        <exclude-pattern>tests/</exclude-pattern>
+    </rule>
+    <rule ref="WordPress.Security.NonceVerification">
+        <exclude-pattern>tests/</exclude-pattern>
+    </rule>
+    <rule ref="WordPress.WP.GlobalVariablesOverride">
+        <exclude-pattern>tests/</exclude-pattern>
+    </rule>
+    <rule ref="NeutronStandard.Functions.TypeHint.UnusedReturnType">
+        <exclude-pattern>tests/TypeInferenceTest.php</exclude-pattern>
+    </rule>
 </ruleset>
diff --git a/tests/bootstrap.php b/tests/bootstrap.php
index bf826eb..634031f 100644
--- a/tests/bootstrap.php
+++ b/tests/bootstrap.php
@@ -4,6 +4,8 @@
 
 namespace PhpStubs\WordPress\Core\Tests;
 
+// phpcs:disable Squiz.PHP.DiscouragedFunctions
 define('OBJECT', 'OBJECT');
 define('ARRAY_A', 'ARRAY_A');
 define('ARRAY_N', 'ARRAY_N');
+// phpcs:enable
diff --git a/tests/data/get_attachment_taxonomies.php b/tests/data/get_attachment_taxonomies.php
index ff26ce6..453de9c 100644
--- a/tests/data/get_attachment_taxonomies.php
+++ b/tests/data/get_attachment_taxonomies.php
@@ -8,19 +8,19 @@
 use function PHPStan\Testing\assertType;
 
 // Default
-assertType('array<int, string>', get_attachment_taxonomies((int)$id));
-assertType('array<int, string>', get_attachment_taxonomies((int)$id, 'names'));
+assertType('array<int, string>', get_attachment_taxonomies((int)$_GET['id']));
+assertType('array<int, string>', get_attachment_taxonomies((int)$_GET['id'], 'names'));
 
 // Objects
-assertType('array<string, WP_Taxonomy>', get_attachment_taxonomies((int)$id, 'objects'));
+assertType('array<string, WP_Taxonomy>', get_attachment_taxonomies((int)$_GET['id'], 'objects'));
 
 // Unexpected
-assertType('array<string, WP_Taxonomy>', get_attachment_taxonomies((int)$id, 'Hello'));
+assertType('array<string, WP_Taxonomy>', get_attachment_taxonomies((int)$_GET['id'], 'Hello'));
 
 // Unknown
-assertType('array<int|string, string|WP_Taxonomy>', get_attachment_taxonomies((int)$id, (string)$_GET['string']));
+assertType('array<int|string, string|WP_Taxonomy>', get_attachment_taxonomies((int)$_GET['id'], (string)$_GET['string']));
 
 // Unions
-assertType('array<int|string, string|WP_Taxonomy>', get_attachment_taxonomies((int)$id, $_GET['foo'] ? 'names' : 'objects'));
-assertType('array<int|string, string|WP_Taxonomy>', get_attachment_taxonomies((int)$id, $_GET['foo'] ? (string)$_GET['string'] : 'names'));
-assertType('array<int|string, string|WP_Taxonomy>', get_attachment_taxonomies((int)$id, $_GET['foo'] ? (string)$_GET['string'] : 'objects'));
+assertType('array<int|string, string|WP_Taxonomy>', get_attachment_taxonomies((int)$_GET['id'], $_GET['foo'] ? 'names' : 'objects'));
+assertType('array<int|string, string|WP_Taxonomy>', get_attachment_taxonomies((int)$_GET['id'], $_GET['foo'] ? (string)$_GET['string'] : 'names'));
+assertType('array<int|string, string|WP_Taxonomy>', get_attachment_taxonomies((int)$_GET['id'], $_GET['foo'] ? (string)$_GET['string'] : 'objects'));
diff --git a/tests/data/get_bookmark.php b/tests/data/get_bookmark.php
index 6f8e327..8f5ea80 100644
--- a/tests/data/get_bookmark.php
+++ b/tests/data/get_bookmark.php
@@ -8,7 +8,7 @@
 use function PHPStan\Testing\assertType;
 
 /** @var \stdClass|int $bookmark */
-$bookmark;
+$bookmark = $_GET['bookmark'];
 
 assertType('stdClass|null', get_bookmark($bookmark));
 assertType('stdClass|null', get_bookmark($bookmark, 'OBJECT'));
diff --git a/tests/data/get_categories.php b/tests/data/get_categories.php
index 9db5941..e225ce0 100644
--- a/tests/data/get_categories.php
+++ b/tests/data/get_categories.php
@@ -13,7 +13,7 @@
 
 // Requesting a count
 assertType('list<numeric-string>', get_categories(['fields' => 'count']));
-assertType('list<numeric-string>', get_categories(['foo' => 'bar','fields' => 'count']));
+assertType('list<numeric-string>', get_categories(['fields' => 'count', 'foo' => 'bar']));
 
 // Requesting names or slugs
 assertType('list<string>', get_categories(['fields' => 'names']));
@@ -31,7 +31,7 @@
 // Requesting objects
 assertType('array<int, WP_Term>', get_categories(['fields' => 'all']));
 assertType('array<int, WP_Term>', get_categories(['fields' => 'all_with_object_id']));
-assertType('array<int, WP_Term>', get_categories(['fields' => 'foo']));
 
 // Unknown fields value
+assertType('array<int, WP_Term>', get_categories(['fields' => 'foo']));
 assertType('array<int, int|string|WP_Term>', get_categories(['fields' => (string)$_GET['fields']]));
diff --git a/tests/data/get_category.php b/tests/data/get_category.php
index 85862da..fe43d14 100644
--- a/tests/data/get_category.php
+++ b/tests/data/get_category.php
@@ -8,7 +8,7 @@
 use function PHPStan\Testing\assertType;
 
 /** @var object $category */
-$category;
+$category = $_GET['category'];
 
 assertType('WP_Term', get_category($category));
 assertType('WP_Term', get_category($category, 'OBJECT'));
@@ -16,7 +16,7 @@
 assertType('array<int, mixed>', get_category($category, 'ARRAY_N'));
 
 /** @var int|object $category */
-$category;
+$category = $_GET['category'];
 
 assertType('WP_Error|WP_Term|null', get_category($category));
 assertType('WP_Error|WP_Term|null', get_category($category, 'OBJECT'));
diff --git a/tests/data/get_category_by_path.php b/tests/data/get_category_by_path.php
index d131772..d109010 100644
--- a/tests/data/get_category_by_path.php
+++ b/tests/data/get_category_by_path.php
@@ -7,10 +7,7 @@
 use function get_category_by_path;
 use function PHPStan\Testing\assertType;
 
-/** @var bool $bool */
-$bool;
-
-assertType('WP_Error|WP_Term|null', get_category_by_path('', $bool));
-assertType('WP_Error|WP_Term|null', get_category_by_path('', $bool, 'OBJECT'));
-assertType('array<string, mixed>|WP_Error|null', get_category_by_path('', $bool, 'ARRAY_A'));
-assertType('array<int, mixed>|WP_Error|null', get_category_by_path('', $bool, 'ARRAY_N'));
+assertType('WP_Error|WP_Term|null', get_category_by_path('', (bool)$_GET['full_match']));
+assertType('WP_Error|WP_Term|null', get_category_by_path('', (bool)$_GET['full_match'], 'OBJECT'));
+assertType('array<string, mixed>|WP_Error|null', get_category_by_path('', (bool)$_GET['full_match'], 'ARRAY_A'));
+assertType('array<int, mixed>|WP_Error|null', get_category_by_path('', (bool)$_GET['full_match'], 'ARRAY_N'));
diff --git a/tests/data/get_comment.php b/tests/data/get_comment.php
index f0bcc77..c986f11 100644
--- a/tests/data/get_comment.php
+++ b/tests/data/get_comment.php
@@ -8,7 +8,7 @@
 use function PHPStan\Testing\assertType;
 
 /** @var \WP_Comment|int|string|null $comment */
-$comment;
+$comment = $_GET['comment'];
 
 // Default output
 assertType('WP_Comment|null', get_comment());
@@ -22,7 +22,7 @@
 assertType('array<int, mixed>|null', get_comment($comment, 'ARRAY_N'));
 
 /** @var \WP_Comment $comment */
-$comment;
+$comment = $_GET['comment'];
 
 assertType('WP_Comment', get_comment($comment));
 assertType('WP_Comment', get_comment($comment, 'OBJECT'));
diff --git a/tests/data/get_permalink.php b/tests/data/get_permalink.php
index 07e5e05..42bb70e 100644
--- a/tests/data/get_permalink.php
+++ b/tests/data/get_permalink.php
@@ -10,7 +10,7 @@
 use function PHPStan\Testing\assertType;
 
 /** @var \WP_Post $post */
-$post = $post;
+$post = $_GET['post'];
 
 // get_permalink()
 assertType('string|false', get_permalink());
diff --git a/tests/data/get_post.php b/tests/data/get_post.php
index 8061772..3bedfb0 100644
--- a/tests/data/get_post.php
+++ b/tests/data/get_post.php
@@ -8,7 +8,7 @@
 use function PHPStan\Testing\assertType;
 
 /** @var \WP_Post|int|null $post */
-$post;
+$post = $_GET['post'];
 
 // Default output
 assertType('WP_Post|null', get_post());
@@ -22,7 +22,7 @@
 assertType('array<int, mixed>|null', get_post($post, 'ARRAY_N'));
 
 /** @var \WP_Post $post */
-$post;
+$post = $_GET['post'];
 
 assertType('WP_Post', get_post($post));
 assertType('WP_Post', get_post($post, 'OBJECT'));
diff --git a/tests/data/wp_die.php b/tests/data/wp_die.php
index aba4a75..fa5a1f9 100644
--- a/tests/data/wp_die.php
+++ b/tests/data/wp_die.php
@@ -21,5 +21,4 @@
 assertType('null', wp_die('', '', (array)$_GET['args']));
 
 // non-array $args parameter ($args not string type per @phpstan-param)
-/** @var int $args */
-assertType('never', wp_die('', '', $args));
+assertType('never', wp_die('', '', (int)$_GET['args']));
diff --git a/tests/data/wp_dropdown_languages.php b/tests/data/wp_dropdown_languages.php
index 38d452b..98e4584 100644
--- a/tests/data/wp_dropdown_languages.php
+++ b/tests/data/wp_dropdown_languages.php
@@ -16,10 +16,10 @@
 use function PHPStan\Testing\assertType;
 
 /** @var ''|null $emptyStringOrNull */
-$emptyStringOrNull = $_GET['nullOrEmptyString'];
+$emptyStringOrNull = $_GET['emptyStringOrNull'];
 
 /** @var string|null $stringOrNull */
-$stringOrNull = $_GET['unknown'];
+$stringOrNull = $_GET['stringOrNull'];
 
 // Default value
 assertType('string', wp_dropdown_languages());
diff --git a/tests/data/wp_get_archives.php b/tests/data/wp_get_archives.php
index 544996d..6760ee7 100644
--- a/tests/data/wp_get_archives.php
+++ b/tests/data/wp_get_archives.php
@@ -27,5 +27,5 @@
 assertType('string', wp_get_archives(['echo' => 0, 'key' => 'value']));
 
 // Unknown value
-assertType('string|null', wp_get_archives(['echo' => (bool)$GET['echo'], 'key' => 'value']));
-assertType('string|null', wp_get_archives(['echo' => (int)$GET['echo'], 'key' => 'value']));
+assertType('string|null', wp_get_archives(['echo' => (bool)$_GET['echo'], 'key' => 'value']));
+assertType('string|null', wp_get_archives(['echo' => (int)$_GET['echo'], 'key' => 'value']));
diff --git a/tests/data/wp_list_bookmarks.php b/tests/data/wp_list_bookmarks.php
index ba51576..bd6db8b 100644
--- a/tests/data/wp_list_bookmarks.php
+++ b/tests/data/wp_list_bookmarks.php
@@ -27,5 +27,5 @@
 assertType('string', wp_list_bookmarks(['echo' => 0, 'key' => 'value']));
 
 // Unknown value
-assertType('string|null', wp_list_bookmarks(['echo' => (bool)$GET['echo'], 'key' => 'value']));
-assertType('string|null', wp_list_bookmarks(['echo' => (int)$GET['echo'], 'key' => 'value']));
+assertType('string|null', wp_list_bookmarks(['echo' => (bool)$_GET['echo'], 'key' => 'value']));
+assertType('string|null', wp_list_bookmarks(['echo' => (int)$_GET['echo'], 'key' => 'value']));
diff --git a/tests/data/wp_list_categories.php b/tests/data/wp_list_categories.php
index 1e88675..2fe86e0 100644
--- a/tests/data/wp_list_categories.php
+++ b/tests/data/wp_list_categories.php
@@ -27,5 +27,5 @@
 assertType('string|false', wp_list_categories(['echo' => 0, 'key' => 'value']));
 
 // Unknown value
-assertType('string|false|null', wp_list_categories(['echo' => (bool)$GET['echo'], 'key' => 'value']));
-assertType('string|false|null', wp_list_categories(['echo' => (int)$GET['echo'], 'key' => 'value']));
+assertType('string|false|null', wp_list_categories(['echo' => (bool)$_GET['echo'], 'key' => 'value']));
+assertType('string|false|null', wp_list_categories(['echo' => (int)$_GET['echo'], 'key' => 'value']));
diff --git a/tests/data/wp_list_pages.php b/tests/data/wp_list_pages.php
index bd5095b..7887889 100644
--- a/tests/data/wp_list_pages.php
+++ b/tests/data/wp_list_pages.php
@@ -25,4 +25,4 @@
 assertType('string', wp_list_pages(['echo' => false, 'key' => 'value']));
 
 // Unknown value
-assertType('string|null', wp_list_pages(['echo' => (bool)$GET['echo'], 'key' => 'value']));
+assertType('string|null', wp_list_pages(['echo' => (bool)$_GET['echo'], 'key' => 'value']));
diff --git a/wordpress-stubs.php b/wordpress-stubs.php
index 1edb024..fd7a5d9 100644
--- a/wordpress-stubs.php
+++ b/wordpress-stubs.php
@@ -112094,7 +112094,7 @@ function map_deep($value, $callback)
      *
      * @param string $input_string The string to be parsed.
      * @param array  $result       Variables will be stored in this array.
-     * @param-out array<int|string, array|string> $result
+     * @phpstan-param-out array<int|string, array|string> $result
      */
     function wp_parse_str($input_string, &$result)
     {