diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 81e12c0b..e07f6d06 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -13,7 +13,7 @@ jobs:
       fail-fast: false
       matrix:
         operating-system: ["ubuntu-latest"]
-        php: ["7.4", "8.0", "8.1", "8.2", "8.3", "8.4", "8.5"]
+        php: ["7.4", "8.0", "8.1", "8.2", "8.3", "8.4", "8.5", "8.6"]
 
     steps:
       - name: Checkout
@@ -93,7 +93,7 @@ jobs:
       fail-fast: false
       matrix:
         operating-system: ["ubuntu-latest"]
-        php: ["8.3"]
+        php: ["8.4"]
         tool: ["phpstan", "code-coverage", "code-style"]
 
     steps:
diff --git a/.phpstan.neon b/.phpstan.neon
index b5eae346..4b04a84b 100644
--- a/.phpstan.neon
+++ b/.phpstan.neon
@@ -5,9 +5,6 @@ parameters:
         - src/
         - tests/
 
-    scanDirectories:
-        - vendor
-
     treatPhpDocTypesAsCertain: false
 
     ignoreErrors:
diff --git a/.rector.php b/.rector.php
new file mode 100644
index 00000000..92d725b5
--- /dev/null
+++ b/.rector.php
@@ -0,0 +1,21 @@
+<?php
+
+declare(strict_types=1);
+
+use Rector\Config\RectorConfig;
+
+return RectorConfig::configure()
+    ->withPaths([
+        __DIR__ . '/src',
+        __DIR__ . '/tests',
+    ])
+    // uncomment to reach your current PHP version
+    //->withPhpSets()
+    ->withPhp74Sets()
+    ->withPhpVersion(70400)
+    ->withRules(\Art4\RectorBcLibrary\Set::withTypeCoverageLevel(28))
+    ->withPreparedSets(
+        true,
+        true
+    )
+;
diff --git a/composer.json b/composer.json
index 6f2a63c5..e96d579e 100644
--- a/composer.json
+++ b/composer.json
@@ -30,12 +30,14 @@
         "psr/http-factory": "^1.0"
     },
     "require-dev": {
+        "art4/rector-bc-library": "1.0.0-beta.0",
         "behat/behat": "^3.14",
         "friendsofphp/php-cs-fixer": "^3.68",
         "guzzlehttp/psr7": "^2",
         "php-mock/php-mock-phpunit": "^2.13",
         "phpstan/phpstan": "^2.1",
-        "phpunit/phpunit": "^9.5 || ^10.5 || ^11.2 || ^12.0.9"
+        "phpunit/phpunit": "^9.5 || ^10.5 || ^11.2 || ^12.0.9",
+        "rector/rector": "^2.2"
     },
     "autoload": {
         "psr-4": {
@@ -62,6 +64,7 @@
         "coverage": "phpunit --coverage-html=\".phpunit.cache/code-coverage\"",
         "phpstan": "phpstan analyze --memory-limit 512M --configuration .phpstan.neon",
         "phpunit": "phpunit",
+        "rector": "rector -c .rector.php",
         "test": [
             "@phpstan",
             "@phpunit",
diff --git a/docker-compose.yml b/docker-compose.yml
index 8b11af78..356ba77a 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -7,6 +7,9 @@ services:
             - 8111:80
         depends_on:
             - redmine-dev
+            - redmine-6-1
+            - redmine-6-0
+            - redmine-5-1
         volumes:
             - ./:/var/www/project/ # Location of the project for php-fpm. Note this should be the same for NGINX.*
 
diff --git a/src/Redmine/Api/AbstractApi.php b/src/Redmine/Api/AbstractApi.php
index 9eb7c497..68962c69 100644
--- a/src/Redmine/Api/AbstractApi.php
+++ b/src/Redmine/Api/AbstractApi.php
@@ -28,10 +28,7 @@ abstract class AbstractApi implements Api
      */
     protected $client;
 
-    /**
-     * @var HttpClient
-     */
-    private $httpClient;
+    private \Redmine\Http\HttpClient $httpClient;
 
     /**
      * @var Response
@@ -73,7 +70,7 @@ final protected function getHttpClient(): HttpClient
 
     final public function getLastResponse(): Response
     {
-        return $this->lastResponse !== null ? $this->lastResponse : HttpFactory::makeResponse(0, '', '');
+        return ($this->lastResponse instanceof Response) ? $this->lastResponse : HttpFactory::makeResponse(0, '', '');
     }
 
     /**
@@ -300,7 +297,7 @@ protected function retrieveAll($endpoint, array $params = [])
      */
     protected function retrieveData(string $endpoint, array $params = []): array
     {
-        if (empty($params)) {
+        if ($params === []) {
             $this->lastResponse = $this->getHttpClient()->request(HttpFactory::makeRequest(
                 'GET',
                 strval($endpoint),
@@ -366,7 +363,7 @@ protected function retrieveData(string $endpoint, array $params = []): array
             $offset += $realLimit;
 
             if (
-                empty($newDataSet)
+                $newDataSet === []
                 || !isset($newDataSet['limit'])
                 || (
                     isset($newDataSet['offset'])
diff --git a/src/Redmine/Api/CustomField.php b/src/Redmine/Api/CustomField.php
index bbd8e799..4e6a34be 100644
--- a/src/Redmine/Api/CustomField.php
+++ b/src/Redmine/Api/CustomField.php
@@ -23,7 +23,7 @@ class CustomField extends AbstractApi
     /**
      * @var null|array<int,string>
      */
-    private $customFieldNames = null;
+    private $customFieldNames;
 
     /**
      * List custom fields.
@@ -83,7 +83,7 @@ final public function listNames(): array
      */
     public function all(array $params = [])
     {
-        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.4.0, use `' . __CLASS__ . '::list()` instead.', E_USER_DEPRECATED);
+        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.4.0, use `' . self::class . '::list()` instead.', E_USER_DEPRECATED);
 
         try {
             $this->customFields = $this->list($params);
@@ -92,7 +92,7 @@ public function all(array $params = [])
                 return false;
             }
 
-            if ($e instanceof UnexpectedResponseException && $e->getPrevious() !== null) {
+            if ($e instanceof UnexpectedResponseException && $e->getPrevious() instanceof \Throwable) {
                 $e = $e->getPrevious();
             }
 
@@ -115,7 +115,7 @@ public function all(array $params = [])
      */
     public function listing($forceUpdate = false, array $params = [])
     {
-        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.7.0, use `' . __CLASS__ . '::listNames()` instead.', E_USER_DEPRECATED);
+        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.7.0, use `' . self::class . '::listNames()` instead.', E_USER_DEPRECATED);
 
         return $this->doListing($forceUpdate, $params);
     }
@@ -133,7 +133,7 @@ public function listing($forceUpdate = false, array $params = [])
      */
     public function getIdByName($name, array $params = [])
     {
-        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.7.0, use `' . __CLASS__ . '::listNames()` instead.', E_USER_DEPRECATED);
+        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.7.0, use `' . self::class . '::listNames()` instead.', E_USER_DEPRECATED);
 
         $arr = $this->doListing(false, $params);
 
@@ -151,7 +151,7 @@ public function getIdByName($name, array $params = [])
      */
     private function doListing(bool $forceUpdate, array $params): array
     {
-        if (empty($this->customFields) || $forceUpdate) {
+        if ($this->customFields === [] || $forceUpdate) {
             $this->customFields = $this->list($params);
         }
 
diff --git a/src/Redmine/Api/Group.php b/src/Redmine/Api/Group.php
index 04d10064..954a4cc9 100644
--- a/src/Redmine/Api/Group.php
+++ b/src/Redmine/Api/Group.php
@@ -29,7 +29,7 @@ class Group extends AbstractApi
     /**
      * @var null|array<int,string>
      */
-    private $groupNames = null;
+    private $groupNames;
 
     /**
      * List groups.
@@ -85,7 +85,7 @@ final public function listNames(): array
      */
     public function all(array $params = [])
     {
-        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.4.0, use `' . __CLASS__ . '::list()` instead.', E_USER_DEPRECATED);
+        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.4.0, use `' . self::class . '::list()` instead.', E_USER_DEPRECATED);
 
         try {
             $this->groups = $this->list($params);
@@ -94,7 +94,7 @@ public function all(array $params = [])
                 return false;
             }
 
-            if ($e instanceof UnexpectedResponseException && $e->getPrevious() !== null) {
+            if ($e instanceof UnexpectedResponseException && $e->getPrevious() instanceof \Throwable) {
                 $e = $e->getPrevious();
             }
 
@@ -116,9 +116,9 @@ public function all(array $params = [])
      */
     public function listing($forceUpdate = false)
     {
-        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.7.0, use `' . __CLASS__ . '::listNames()` instead.', E_USER_DEPRECATED);
+        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.7.0, use `' . self::class . '::listNames()` instead.', E_USER_DEPRECATED);
 
-        if (empty($this->groups) || $forceUpdate) {
+        if ($this->groups === [] || $forceUpdate) {
             $this->groups = $this->list();
         }
         $ret = [];
diff --git a/src/Redmine/Api/Issue.php b/src/Redmine/Api/Issue.php
index 3b052777..267f1a63 100644
--- a/src/Redmine/Api/Issue.php
+++ b/src/Redmine/Api/Issue.php
@@ -126,7 +126,7 @@ final public function list(array $params = []): array
      */
     public function all(array $params = [])
     {
-        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.4.0, use `' . __CLASS__ . '::list()` instead.', E_USER_DEPRECATED);
+        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.4.0, use `' . self::class . '::list()` instead.', E_USER_DEPRECATED);
 
         try {
             return $this->list($params);
@@ -135,7 +135,7 @@ public function all(array $params = [])
                 return false;
             }
 
-            if ($e instanceof UnexpectedResponseException && $e->getPrevious() !== null) {
+            if ($e instanceof UnexpectedResponseException && $e->getPrevious() instanceof \Throwable) {
                 $e = $e->getPrevious();
             }
 
diff --git a/src/Redmine/Api/IssueCategory.php b/src/Redmine/Api/IssueCategory.php
index fa16fb39..443f1b94 100644
--- a/src/Redmine/Api/IssueCategory.php
+++ b/src/Redmine/Api/IssueCategory.php
@@ -111,7 +111,7 @@ final public function listNamesByProject($projectIdentifier): array
      */
     public function all($project, array $params = [])
     {
-        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.4.0, use `' . __CLASS__ . '::listByProject()` instead.', E_USER_DEPRECATED);
+        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.4.0, use `' . self::class . '::listByProject()` instead.', E_USER_DEPRECATED);
 
         try {
             return $this->listByProject(strval($project), $params);
@@ -120,7 +120,7 @@ public function all($project, array $params = [])
                 return false;
             }
 
-            if ($e instanceof UnexpectedResponseException && $e->getPrevious() !== null) {
+            if ($e instanceof UnexpectedResponseException && $e->getPrevious() instanceof \Throwable) {
                 $e = $e->getPrevious();
             }
 
@@ -141,7 +141,7 @@ public function all($project, array $params = [])
      */
     public function listing($project, $forceUpdate = false)
     {
-        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.7.0, use `' . __CLASS__ . '::listNamesByProject()` instead.', E_USER_DEPRECATED);
+        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.7.0, use `' . self::class . '::listNamesByProject()` instead.', E_USER_DEPRECATED);
 
         return $this->doListing($project, $forceUpdate);
     }
@@ -159,7 +159,7 @@ public function listing($project, $forceUpdate = false)
      */
     public function getIdByName($project, $name)
     {
-        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.7.0, use `' . __CLASS__ . '::listNamesByProject()` instead.', E_USER_DEPRECATED);
+        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.7.0, use `' . self::class . '::listNamesByProject()` instead.', E_USER_DEPRECATED);
 
         $arr = $this->doListing($project, false);
 
@@ -296,7 +296,7 @@ public function remove($id, array $params = [])
      */
     private function doListing($projectIdentifier, bool $forceUpdate): array
     {
-        if (true === $forceUpdate || empty($this->issueCategories)) {
+        if ($forceUpdate || $this->issueCategories === []) {
             $this->issueCategories = $this->listByProject($projectIdentifier);
         }
 
diff --git a/src/Redmine/Api/IssuePriority.php b/src/Redmine/Api/IssuePriority.php
index 6a6ca25b..167a590b 100644
--- a/src/Redmine/Api/IssuePriority.php
+++ b/src/Redmine/Api/IssuePriority.php
@@ -54,7 +54,7 @@ final public function list(array $params = []): array
      */
     public function all(array $params = [])
     {
-        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.4.0, use `' . __CLASS__ . '::list()` instead.', E_USER_DEPRECATED);
+        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.4.0, use `' . self::class . '::list()` instead.', E_USER_DEPRECATED);
 
         try {
             $this->issuePriorities = $this->list($params);
@@ -63,7 +63,7 @@ public function all(array $params = [])
                 return false;
             }
 
-            if ($e instanceof UnexpectedResponseException && $e->getPrevious() !== null) {
+            if ($e instanceof UnexpectedResponseException && $e->getPrevious() instanceof \Throwable) {
                 $e = $e->getPrevious();
             }
 
diff --git a/src/Redmine/Api/IssueRelation.php b/src/Redmine/Api/IssueRelation.php
index 36849c3e..33cdd415 100644
--- a/src/Redmine/Api/IssueRelation.php
+++ b/src/Redmine/Api/IssueRelation.php
@@ -59,7 +59,7 @@ final public function listByIssueId(int $issueId, array $params = []): array
      */
     public function all($issueId, array $params = [])
     {
-        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.4.0, use `' . __CLASS__ . '::listByIssueId()` instead.', E_USER_DEPRECATED);
+        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.4.0, use `' . self::class . '::listByIssueId()` instead.', E_USER_DEPRECATED);
 
         try {
             $this->relations = $this->listByIssueId($issueId, $params);
@@ -68,7 +68,7 @@ public function all($issueId, array $params = [])
                 return false;
             }
 
-            if ($e instanceof UnexpectedResponseException && $e->getPrevious() !== null) {
+            if ($e instanceof UnexpectedResponseException && $e->getPrevious() instanceof \Throwable) {
                 $e = $e->getPrevious();
             }
 
diff --git a/src/Redmine/Api/IssueStatus.php b/src/Redmine/Api/IssueStatus.php
index 293ed989..dff5e438 100644
--- a/src/Redmine/Api/IssueStatus.php
+++ b/src/Redmine/Api/IssueStatus.php
@@ -23,7 +23,7 @@ class IssueStatus extends AbstractApi
     /**
      * @var array<int,string>
      */
-    private $issueStatusNames = null;
+    private $issueStatusNames;
 
     /**
      * List issue statuses.
@@ -83,7 +83,7 @@ final public function listNames(): array
      */
     public function all(array $params = [])
     {
-        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.4.0, use `' . __CLASS__ . '::list()` instead.', E_USER_DEPRECATED);
+        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.4.0, use `' . self::class . '::list()` instead.', E_USER_DEPRECATED);
 
         try {
             $this->issueStatuses = $this->list($params);
@@ -92,7 +92,7 @@ public function all(array $params = [])
                 return false;
             }
 
-            if ($e instanceof UnexpectedResponseException && $e->getPrevious() !== null) {
+            if ($e instanceof UnexpectedResponseException && $e->getPrevious() instanceof \Throwable) {
                 $e = $e->getPrevious();
             }
 
@@ -114,7 +114,7 @@ public function all(array $params = [])
      */
     public function listing($forceUpdate = false)
     {
-        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.7.0, use `' . __CLASS__ . '::listNames()` instead.', E_USER_DEPRECATED);
+        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.7.0, use `' . self::class . '::listNames()` instead.', E_USER_DEPRECATED);
 
         return $this->doListing($forceUpdate);
     }
@@ -131,7 +131,7 @@ public function listing($forceUpdate = false)
      */
     public function getIdByName($name)
     {
-        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.7.0, use `' . __CLASS__ . '::listNames()` instead.', E_USER_DEPRECATED);
+        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.7.0, use `' . self::class . '::listNames()` instead.', E_USER_DEPRECATED);
 
         $arr = $this->doListing(false);
 
@@ -147,7 +147,7 @@ public function getIdByName($name)
      */
     private function doListing(bool $forceUpdate): array
     {
-        if (empty($this->issueStatuses) || $forceUpdate) {
+        if ($this->issueStatuses === [] || $forceUpdate) {
             $this->issueStatuses = $this->list();
         }
 
diff --git a/src/Redmine/Api/Membership.php b/src/Redmine/Api/Membership.php
index 81dc3de0..65f83220 100644
--- a/src/Redmine/Api/Membership.php
+++ b/src/Redmine/Api/Membership.php
@@ -69,7 +69,7 @@ final public function listByProject($projectIdentifier, array $params = []): arr
      */
     public function all($project, array $params = [])
     {
-        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.4.0, use `' . __CLASS__ . '::listByProject()` instead.', E_USER_DEPRECATED);
+        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.4.0, use `' . self::class . '::listByProject()` instead.', E_USER_DEPRECATED);
 
         try {
             $this->memberships = $this->listByProject(strval($project), $params);
@@ -78,7 +78,7 @@ public function all($project, array $params = [])
                 return false;
             }
 
-            if ($e instanceof UnexpectedResponseException && $e->getPrevious() !== null) {
+            if ($e instanceof UnexpectedResponseException && $e->getPrevious() instanceof \Throwable) {
                 $e = $e->getPrevious();
             }
 
diff --git a/src/Redmine/Api/News.php b/src/Redmine/Api/News.php
index 629fdcb1..f1473125 100644
--- a/src/Redmine/Api/News.php
+++ b/src/Redmine/Api/News.php
@@ -84,20 +84,16 @@ final public function list(array $params = []): array
      */
     public function all($project = null, array $params = [])
     {
-        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.4.0, use `' . __CLASS__ . '::list()` or `' . __CLASS__ . '::listByProject()` instead.', E_USER_DEPRECATED);
+        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.4.0, use `' . self::class . '::list()` or `' . self::class . '::listByProject()` instead.', E_USER_DEPRECATED);
 
         try {
-            if (null === $project) {
-                $this->news = $this->list($params);
-            } else {
-                $this->news = $this->listByProject(strval($project), $params);
-            }
+            $this->news = null === $project ? $this->list($params) : $this->listByProject(strval($project), $params);
         } catch (Exception $e) {
             if ($this->getLastResponse()->getContent() === '') {
                 return false;
             }
 
-            if ($e instanceof UnexpectedResponseException && $e->getPrevious() !== null) {
+            if ($e instanceof UnexpectedResponseException && $e->getPrevious() instanceof \Throwable) {
                 $e = $e->getPrevious();
             }
 
diff --git a/src/Redmine/Api/Project.php b/src/Redmine/Api/Project.php
index 50ed0c46..e1e78e84 100755
--- a/src/Redmine/Api/Project.php
+++ b/src/Redmine/Api/Project.php
@@ -30,7 +30,7 @@ class Project extends AbstractApi
     /**
      * @var null|array<int,string>
      */
-    private $projectNames = null;
+    private $projectNames;
 
     /**
      * List projects.
@@ -103,7 +103,7 @@ final public function listNames(): array
      */
     public function all(array $params = [])
     {
-        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.4.0, use `' . __CLASS__ . '::list()` instead.', E_USER_DEPRECATED);
+        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.4.0, use `' . self::class . '::list()` instead.', E_USER_DEPRECATED);
 
         try {
             $this->projects = $this->list($params);
@@ -112,7 +112,7 @@ public function all(array $params = [])
                 return false;
             }
 
-            if ($e instanceof UnexpectedResponseException && $e->getPrevious() !== null) {
+            if ($e instanceof UnexpectedResponseException && $e->getPrevious() instanceof \Throwable) {
                 $e = $e->getPrevious();
             }
 
@@ -136,7 +136,7 @@ public function all(array $params = [])
      */
     public function listing($forceUpdate = false, $reverse = true, array $params = [])
     {
-        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.7.0, use `' . __CLASS__ . '::listNames()` instead.', E_USER_DEPRECATED);
+        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.7.0, use `' . self::class . '::listNames()` instead.', E_USER_DEPRECATED);
 
         return $this->doListing($forceUpdate, $reverse, $params);
     }
@@ -154,7 +154,7 @@ public function listing($forceUpdate = false, $reverse = true, array $params = [
      */
     public function getIdByName($name, array $params = [])
     {
-        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.7.0, use `' . __CLASS__ . '::listNames()` instead.', E_USER_DEPRECATED);
+        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.7.0, use `' . self::class . '::listNames()` instead.', E_USER_DEPRECATED);
 
         $arr = $this->doListing(false, true, $params);
 
@@ -460,7 +460,7 @@ public function remove($id)
      */
     private function doListing(bool $forceUpdate, bool $reverse, array $params): array
     {
-        if (true === $forceUpdate || empty($this->projects)) {
+        if ($forceUpdate || $this->projects === []) {
             $this->projects = $this->list($params);
         }
 
diff --git a/src/Redmine/Api/Query.php b/src/Redmine/Api/Query.php
index 35232c6a..7997b06d 100644
--- a/src/Redmine/Api/Query.php
+++ b/src/Redmine/Api/Query.php
@@ -54,7 +54,7 @@ final public function list(array $params = []): array
      */
     public function all(array $params = [])
     {
-        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.4.0, use `' . __CLASS__ . '::list()` instead.', E_USER_DEPRECATED);
+        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.4.0, use `' . self::class . '::list()` instead.', E_USER_DEPRECATED);
 
         try {
             $this->query = $this->list($params);
@@ -63,7 +63,7 @@ public function all(array $params = [])
                 return false;
             }
 
-            if ($e instanceof UnexpectedResponseException && $e->getPrevious() !== null) {
+            if ($e instanceof UnexpectedResponseException && $e->getPrevious() instanceof \Throwable) {
                 $e = $e->getPrevious();
             }
 
diff --git a/src/Redmine/Api/Role.php b/src/Redmine/Api/Role.php
index 8e61cb85..b1c85235 100644
--- a/src/Redmine/Api/Role.php
+++ b/src/Redmine/Api/Role.php
@@ -25,7 +25,7 @@ class Role extends AbstractApi
     /**
      * @var null|array<int,string>
      */
-    private $roleNames = null;
+    private $roleNames;
 
     /**
      * List roles.
@@ -84,7 +84,7 @@ final public function listNames(): array
      */
     public function all(array $params = [])
     {
-        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.4.0, use `' . __CLASS__ . '::list()` instead.', E_USER_DEPRECATED);
+        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.4.0, use `' . self::class . '::list()` instead.', E_USER_DEPRECATED);
 
         try {
             $this->roles = $this->list($params);
@@ -93,7 +93,7 @@ public function all(array $params = [])
                 return false;
             }
 
-            if ($e instanceof UnexpectedResponseException && $e->getPrevious() !== null) {
+            if ($e instanceof UnexpectedResponseException && $e->getPrevious() instanceof \Throwable) {
                 $e = $e->getPrevious();
             }
 
@@ -115,9 +115,9 @@ public function all(array $params = [])
      */
     public function listing($forceUpdate = false)
     {
-        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.7.0, use `' . __CLASS__ . '::listNames()` instead.', E_USER_DEPRECATED);
+        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.7.0, use `' . self::class . '::listNames()` instead.', E_USER_DEPRECATED);
 
-        if (empty($this->roles) || $forceUpdate) {
+        if ($this->roles === [] || $forceUpdate) {
             $this->roles = $this->list();
         }
         $ret = [];
diff --git a/src/Redmine/Api/Search.php b/src/Redmine/Api/Search.php
index 0b31e2a0..6d36ed7e 100644
--- a/src/Redmine/Api/Search.php
+++ b/src/Redmine/Api/Search.php
@@ -54,7 +54,7 @@ final public function listByQuery(string $query, array $params = []): array
      */
     public function search($query, array $params = [])
     {
-        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.4.0, use `' . __CLASS__ . '::listByQuery()` instead.', E_USER_DEPRECATED);
+        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.4.0, use `' . self::class . '::listByQuery()` instead.', E_USER_DEPRECATED);
 
         try {
             $this->results = $this->listByQuery($query, $params);
@@ -63,7 +63,7 @@ public function search($query, array $params = [])
                 return false;
             }
 
-            if ($e instanceof UnexpectedResponseException && $e->getPrevious() !== null) {
+            if ($e instanceof UnexpectedResponseException && $e->getPrevious() instanceof \Throwable) {
                 $e = $e->getPrevious();
             }
 
diff --git a/src/Redmine/Api/TimeEntry.php b/src/Redmine/Api/TimeEntry.php
index 5ad6e088..65b39ef4 100644
--- a/src/Redmine/Api/TimeEntry.php
+++ b/src/Redmine/Api/TimeEntry.php
@@ -59,7 +59,7 @@ final public function list(array $params = []): array
      */
     public function all(array $params = [])
     {
-        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.4.0, use `' . __CLASS__ . '::list()` instead.', E_USER_DEPRECATED);
+        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.4.0, use `' . self::class . '::list()` instead.', E_USER_DEPRECATED);
 
         try {
             $this->timeEntries = $this->list($params);
@@ -68,7 +68,7 @@ public function all(array $params = [])
                 return false;
             }
 
-            if ($e instanceof UnexpectedResponseException && $e->getPrevious() !== null) {
+            if ($e instanceof UnexpectedResponseException && $e->getPrevious() instanceof \Throwable) {
                 $e = $e->getPrevious();
             }
 
diff --git a/src/Redmine/Api/TimeEntryActivity.php b/src/Redmine/Api/TimeEntryActivity.php
index 7cda0f09..5bd2a69c 100644
--- a/src/Redmine/Api/TimeEntryActivity.php
+++ b/src/Redmine/Api/TimeEntryActivity.php
@@ -23,7 +23,7 @@ class TimeEntryActivity extends AbstractApi
     /**
      * @var null|array<string>
      */
-    private $timeEntryActivityNames = null;
+    private $timeEntryActivityNames;
 
     /**
      * List time entry activities.
@@ -78,7 +78,7 @@ final public function listNames(): array
      */
     public function all(array $params = [])
     {
-        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.4.0, use `' . __CLASS__ . '::list()` instead.', E_USER_DEPRECATED);
+        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.4.0, use `' . self::class . '::list()` instead.', E_USER_DEPRECATED);
 
         try {
             $this->timeEntryActivities = $this->list($params);
@@ -87,7 +87,7 @@ public function all(array $params = [])
                 return false;
             }
 
-            if ($e instanceof UnexpectedResponseException && $e->getPrevious() !== null) {
+            if ($e instanceof UnexpectedResponseException && $e->getPrevious() instanceof \Throwable) {
                 $e = $e->getPrevious();
             }
 
@@ -109,7 +109,7 @@ public function all(array $params = [])
      */
     public function listing($forceUpdate = false)
     {
-        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.7.0, use `' . __CLASS__ . '::listNames()` instead.', E_USER_DEPRECATED);
+        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.7.0, use `' . self::class . '::listNames()` instead.', E_USER_DEPRECATED);
 
         return $this->doListing((bool) $forceUpdate);
     }
@@ -126,7 +126,7 @@ public function listing($forceUpdate = false)
      */
     public function getIdByName($name)
     {
-        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.7.0, use `' . __CLASS__ . '::listNames()` instead.', E_USER_DEPRECATED);
+        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.7.0, use `' . self::class . '::listNames()` instead.', E_USER_DEPRECATED);
 
         $arr = $this->doListing(false);
 
@@ -142,7 +142,7 @@ public function getIdByName($name)
      */
     private function doListing(bool $forceUpdate): array
     {
-        if (empty($this->timeEntryActivities) || $forceUpdate) {
+        if ($this->timeEntryActivities === [] || $forceUpdate) {
             $this->timeEntryActivities = $this->list();
         }
 
diff --git a/src/Redmine/Api/Tracker.php b/src/Redmine/Api/Tracker.php
index 6d2c1ac1..36cdf415 100644
--- a/src/Redmine/Api/Tracker.php
+++ b/src/Redmine/Api/Tracker.php
@@ -23,7 +23,7 @@ class Tracker extends AbstractApi
     /**
      * @var null|array<int,string>
      */
-    private $trackerNames = null;
+    private $trackerNames;
 
     /**
      * List trackers.
@@ -82,7 +82,7 @@ final public function listNames(): array
      */
     public function all(array $params = [])
     {
-        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.4.0, use `' . __CLASS__ . '::list()` instead.', E_USER_DEPRECATED);
+        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.4.0, use `' . self::class . '::list()` instead.', E_USER_DEPRECATED);
 
         try {
             $this->trackers = $this->list($params);
@@ -91,7 +91,7 @@ public function all(array $params = [])
                 return false;
             }
 
-            if ($e instanceof UnexpectedResponseException && $e->getPrevious() !== null) {
+            if ($e instanceof UnexpectedResponseException && $e->getPrevious() instanceof \Throwable) {
                 $e = $e->getPrevious();
             }
 
@@ -113,7 +113,7 @@ public function all(array $params = [])
      */
     public function listing($forceUpdate = false)
     {
-        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.7.0, use `' . __CLASS__ . '::listNames()` instead.', E_USER_DEPRECATED);
+        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.7.0, use `' . self::class . '::listNames()` instead.', E_USER_DEPRECATED);
 
         return $this->doListing($forceUpdate);
     }
@@ -130,7 +130,7 @@ public function listing($forceUpdate = false)
      */
     public function getIdByName($name)
     {
-        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.7.0, use `' . __CLASS__ . '::listNames()` instead.', E_USER_DEPRECATED);
+        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.7.0, use `' . self::class . '::listNames()` instead.', E_USER_DEPRECATED);
 
         $arr = $this->doListing(false);
 
@@ -146,7 +146,7 @@ public function getIdByName($name)
      */
     private function doListing(bool $forceUpdate): array
     {
-        if (empty($this->trackers) || $forceUpdate) {
+        if ($this->trackers === [] || $forceUpdate) {
             $this->trackers = $this->list();
         }
 
diff --git a/src/Redmine/Api/User.php b/src/Redmine/Api/User.php
index dbec8396..a3d4639a 100644
--- a/src/Redmine/Api/User.php
+++ b/src/Redmine/Api/User.php
@@ -29,7 +29,7 @@ class User extends AbstractApi
     /**
      * @var null|array<int,string>
      */
-    private $userLogins = null;
+    private $userLogins;
 
     /**
      * List users.
@@ -102,7 +102,7 @@ final public function listLogins(): array
      */
     public function all(array $params = [])
     {
-        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.4.0, use `' . __CLASS__ . '::list()` instead.', E_USER_DEPRECATED);
+        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.4.0, use `' . self::class . '::list()` instead.', E_USER_DEPRECATED);
 
         try {
             $this->users = $this->list($params);
@@ -111,7 +111,7 @@ public function all(array $params = [])
                 return false;
             }
 
-            if ($e instanceof UnexpectedResponseException && $e->getPrevious() !== null) {
+            if ($e instanceof UnexpectedResponseException && $e->getPrevious() instanceof \Throwable) {
                 $e = $e->getPrevious();
             }
 
@@ -134,7 +134,7 @@ public function all(array $params = [])
      */
     public function listing($forceUpdate = false, array $params = [])
     {
-        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.7.0, use `' . __CLASS__ . '::listLogins()` instead.', E_USER_DEPRECATED);
+        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.7.0, use `' . self::class . '::listLogins()` instead.', E_USER_DEPRECATED);
 
         return $this->doListing($forceUpdate, $params);
     }
@@ -166,7 +166,7 @@ public function getCurrentUser(array $params = [])
      */
     public function getIdByUsername($username, array $params = [])
     {
-        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.7.0, use `' . __CLASS__ . '::listLogins()` instead.', E_USER_DEPRECATED);
+        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.7.0, use `' . self::class . '::listLogins()` instead.', E_USER_DEPRECATED);
 
         $arr = $this->doListing(false, $params);
 
@@ -199,7 +199,7 @@ public function show($id, array $params = [])
         // set default ones
         $params['include'] = array_unique(
             array_merge(
-                isset($params['include']) ? $params['include'] : [],
+                $params['include'] ?? [],
                 [
                     'memberships',
                     'groups',
@@ -329,7 +329,7 @@ public function remove($id)
      */
     private function doListing(bool $forceUpdate, array $params): array
     {
-        if (empty($this->users) || $forceUpdate) {
+        if ($this->users === [] || $forceUpdate) {
             $this->users = $this->list($params);
         }
 
diff --git a/src/Redmine/Api/Version.php b/src/Redmine/Api/Version.php
index 5c355116..aa7f83e8 100644
--- a/src/Redmine/Api/Version.php
+++ b/src/Redmine/Api/Version.php
@@ -109,7 +109,7 @@ final public function listNamesByProject($projectIdentifier): array
      */
     public function all($project, array $params = [])
     {
-        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.4.0, use `' . __CLASS__ . '::listByProject()` instead.', E_USER_DEPRECATED);
+        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.4.0, use `' . self::class . '::listByProject()` instead.', E_USER_DEPRECATED);
 
         try {
             $this->versions = $this->listByProject(strval($project), $params);
@@ -118,7 +118,7 @@ public function all($project, array $params = [])
                 return false;
             }
 
-            if ($e instanceof UnexpectedResponseException && $e->getPrevious() !== null) {
+            if ($e instanceof UnexpectedResponseException && $e->getPrevious() instanceof \Throwable) {
                 $e = $e->getPrevious();
             }
 
@@ -143,7 +143,7 @@ public function all($project, array $params = [])
      */
     public function listing($project, $forceUpdate = false, $reverse = true, array $params = [])
     {
-        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.7.0, use `' . __CLASS__ . '::listNamesByProject()` instead.', E_USER_DEPRECATED);
+        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.7.0, use `' . self::class . '::listNamesByProject()` instead.', E_USER_DEPRECATED);
 
         return $this->doListing($project, $forceUpdate, $reverse, $params);
     }
@@ -162,7 +162,7 @@ public function listing($project, $forceUpdate = false, $reverse = true, array $
      */
     public function getIdByName($project, $name, array $params = [])
     {
-        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.7.0, use `' . __CLASS__ . '::listNamesByProject()` instead.', E_USER_DEPRECATED);
+        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.7.0, use `' . self::class . '::listNamesByProject()` instead.', E_USER_DEPRECATED);
 
         $arr = $this->doListing($project, false, true, $params);
 
@@ -345,7 +345,7 @@ public function remove($id)
      */
     private function doListing($projectIdentifier, bool $forceUpdate, bool $reverse, array $params): array
     {
-        if (true === $forceUpdate || empty($this->versions)) {
+        if ($forceUpdate || $this->versions === []) {
             $this->versions = $this->listByProject($projectIdentifier, $params);
         }
 
diff --git a/src/Redmine/Api/Wiki.php b/src/Redmine/Api/Wiki.php
index 224ec81f..24fba406 100644
--- a/src/Redmine/Api/Wiki.php
+++ b/src/Redmine/Api/Wiki.php
@@ -69,7 +69,7 @@ final public function listByProject($projectIdentifier, array $params = []): arr
      */
     public function all($project, array $params = [])
     {
-        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.4.0, use `' . __CLASS__ . '::listByProject()` instead.', E_USER_DEPRECATED);
+        @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.4.0, use `' . self::class . '::listByProject()` instead.', E_USER_DEPRECATED);
 
         try {
             $this->wikiPages = $this->listByProject(strval($project), $params);
@@ -78,7 +78,7 @@ public function all($project, array $params = [])
                 return false;
             }
 
-            if ($e instanceof UnexpectedResponseException && $e->getPrevious() !== null) {
+            if ($e instanceof UnexpectedResponseException && $e->getPrevious() instanceof \Throwable) {
                 $e = $e->getPrevious();
             }
 
diff --git a/src/Redmine/Client/ClientApiTrait.php b/src/Redmine/Client/ClientApiTrait.php
index 3c1ad4a3..41215670 100644
--- a/src/Redmine/Client/ClientApiTrait.php
+++ b/src/Redmine/Client/ClientApiTrait.php
@@ -21,26 +21,26 @@ trait ClientApiTrait
      * @var array<string,string>
      */
     private array $apiClassnames = [
-        'attachment' => 'Redmine\Api\Attachment',
-        'group' => 'Redmine\Api\Group',
-        'custom_fields' => 'Redmine\Api\CustomField',
-        'issue' => 'Redmine\Api\Issue',
-        'issue_category' => 'Redmine\Api\IssueCategory',
-        'issue_priority' => 'Redmine\Api\IssuePriority',
-        'issue_relation' => 'Redmine\Api\IssueRelation',
-        'issue_status' => 'Redmine\Api\IssueStatus',
-        'membership' => 'Redmine\Api\Membership',
-        'news' => 'Redmine\Api\News',
-        'project' => 'Redmine\Api\Project',
-        'query' => 'Redmine\Api\Query',
-        'role' => 'Redmine\Api\Role',
-        'search' => 'Redmine\Api\Search',
-        'time_entry' => 'Redmine\Api\TimeEntry',
-        'time_entry_activity' => 'Redmine\Api\TimeEntryActivity',
-        'tracker' => 'Redmine\Api\Tracker',
-        'user' => 'Redmine\Api\User',
-        'version' => 'Redmine\Api\Version',
-        'wiki' => 'Redmine\Api\Wiki',
+        'attachment' => \Redmine\Api\Attachment::class,
+        'group' => \Redmine\Api\Group::class,
+        'custom_fields' => \Redmine\Api\CustomField::class,
+        'issue' => \Redmine\Api\Issue::class,
+        'issue_category' => \Redmine\Api\IssueCategory::class,
+        'issue_priority' => \Redmine\Api\IssuePriority::class,
+        'issue_relation' => \Redmine\Api\IssueRelation::class,
+        'issue_status' => \Redmine\Api\IssueStatus::class,
+        'membership' => \Redmine\Api\Membership::class,
+        'news' => \Redmine\Api\News::class,
+        'project' => \Redmine\Api\Project::class,
+        'query' => \Redmine\Api\Query::class,
+        'role' => \Redmine\Api\Role::class,
+        'search' => \Redmine\Api\Search::class,
+        'time_entry' => \Redmine\Api\TimeEntry::class,
+        'time_entry_activity' => \Redmine\Api\TimeEntryActivity::class,
+        'tracker' => \Redmine\Api\Tracker::class,
+        'user' => \Redmine\Api\User::class,
+        'version' => \Redmine\Api\Version::class,
+        'wiki' => \Redmine\Api\Wiki::class,
     ];
 
     /**
diff --git a/src/Redmine/Client/NativeCurlClient.php b/src/Redmine/Client/NativeCurlClient.php
index 6dfb2c06..a98d0038 100644
--- a/src/Redmine/Client/NativeCurlClient.php
+++ b/src/Redmine/Client/NativeCurlClient.php
@@ -410,13 +410,11 @@ private function createHttpHeader(string $path, string $contentType = ''): array
         // @see https://www.redmine.org/projects/redmine/wiki/Rest_api#Authentication
         if (null === $this->password && !array_key_exists(strtolower('X-Redmine-API-Key'), $this->httpHeadersNames)) {
             $httpHeaders[] = 'X-Redmine-API-Key: ' . $this->apikeyOrUsername;
-        } else {
-            if (!array_key_exists(strtolower('Authorization'), $this->httpHeadersNames)) {
-                // Setting Header "Authorization: Basic base64" is the same as
-                // $this->setCurlOption(CURLOPT_USERPWD, "$username:$password")
-                // @see https://stackoverflow.com/a/26285941
-                $httpHeaders[] = 'Authorization: Basic ' . base64_encode($this->apikeyOrUsername . ':' . $this->password);
-            }
+        } elseif (!array_key_exists(strtolower('Authorization'), $this->httpHeadersNames)) {
+            // Setting Header "Authorization: Basic base64" is the same as
+            // $this->setCurlOption(CURLOPT_USERPWD, "$username:$password")
+            // @see https://stackoverflow.com/a/26285941
+            $httpHeaders[] = 'Authorization: Basic ' . base64_encode($this->apikeyOrUsername . ':' . $this->password);
         }
 
         // prepare custom headers
diff --git a/src/Redmine/Client/Psr18Client.php b/src/Redmine/Client/Psr18Client.php
index 454c807c..dc5c5ffa 100644
--- a/src/Redmine/Client/Psr18Client.php
+++ b/src/Redmine/Client/Psr18Client.php
@@ -201,7 +201,7 @@ public function getLastResponseStatusCode(): int
     {
         @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.8.0, use `\Redmine\Api\AbstractApi::getLastResponse()` instead.', E_USER_DEPRECATED);
 
-        if (null === $this->lastResponse) {
+        if (!$this->lastResponse instanceof \Psr\Http\Message\ResponseInterface) {
             return 0;
         }
 
@@ -218,7 +218,7 @@ public function getLastResponseContentType(): string
     {
         @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.8.0, use `\Redmine\Api\AbstractApi::getLastResponse()` instead.', E_USER_DEPRECATED);
 
-        if (null === $this->lastResponse) {
+        if (!$this->lastResponse instanceof \Psr\Http\Message\ResponseInterface) {
             return '';
         }
 
@@ -235,7 +235,7 @@ public function getLastResponseBody(): string
     {
         @trigger_error('`' . __METHOD__ . '()` is deprecated since v2.8.0, use `\Redmine\Api\AbstractApi::getLastResponse()` instead.', E_USER_DEPRECATED);
 
-        if (null === $this->lastResponse) {
+        if (!$this->lastResponse instanceof \Psr\Http\Message\ResponseInterface) {
             return '';
         }
 
diff --git a/src/Redmine/Exception/UnexpectedResponseException.php b/src/Redmine/Exception/UnexpectedResponseException.php
index 12d65746..75ed2a38 100644
--- a/src/Redmine/Exception/UnexpectedResponseException.php
+++ b/src/Redmine/Exception/UnexpectedResponseException.php
@@ -19,13 +19,13 @@ final class UnexpectedResponseException extends RuntimeException implements Redm
     /**
      * @var Response|null
      */
-    private $response = null;
+    private $response;
 
     public static function create(Response $response, ?Throwable $prev = null): self
     {
         $e = new self(
             'The Redmine server replied with an unexpected response.',
-            ($prev !== null) ? $prev->getCode() : 1,
+            ($prev instanceof \Throwable) ? $prev->getCode() : 1,
             $prev,
         );
 
diff --git a/src/Redmine/Http/HttpFactory.php b/src/Redmine/Http/HttpFactory.php
index b7cc4478..7d9c6130 100644
--- a/src/Redmine/Http/HttpFactory.php
+++ b/src/Redmine/Http/HttpFactory.php
@@ -80,11 +80,11 @@ public function getContent(): string
 
     public static function makeJsonRequest(string $method, string $path, string $content = ''): Request
     {
-        return static::makeRequest($method, $path, 'application/json', $content);
+        return self::makeRequest($method, $path, 'application/json', $content);
     }
 
     public static function makeXmlRequest(string $method, string $path, string $content = ''): Request
     {
-        return static::makeRequest($method, $path, 'application/xml', $content);
+        return self::makeRequest($method, $path, 'application/xml', $content);
     }
 }
diff --git a/src/Redmine/Serializer/PathSerializer.php b/src/Redmine/Serializer/PathSerializer.php
index c0191472..9926b6fb 100644
--- a/src/Redmine/Serializer/PathSerializer.php
+++ b/src/Redmine/Serializer/PathSerializer.php
@@ -37,7 +37,7 @@ public function getPath(): string
     {
         $queryString = '';
 
-        if (!empty($this->queryParams)) {
+        if ($this->queryParams !== []) {
             $queryString = '?' . \http_build_query($this->queryParams);
 
             // @see #154: replace every encoded array (`foo[0]=`, `foo[1]=`, etc with `foo[]=`)
diff --git a/tests/Behat/Bootstrap/FeatureContext.php b/tests/Behat/Bootstrap/FeatureContext.php
index 48af4c9f..879e147d 100644
--- a/tests/Behat/Bootstrap/FeatureContext.php
+++ b/tests/Behat/Bootstrap/FeatureContext.php
@@ -45,27 +45,27 @@ final class FeatureContext implements Context
     /**
      * @BeforeSuite
      */
-    public static function prepare(BeforeSuiteScope $scope)
+    public static function prepare(BeforeSuiteScope $scope): void
     {
-        static::$tracer = new BehatHookTracer();
-        static::$tracer->hook($scope);
+        self::$tracer = new BehatHookTracer();
+        self::$tracer->hook($scope);
     }
 
     /**
      * @AfterScenario
      */
-    public static function reset(AfterScenarioScope $scope)
+    public static function reset(AfterScenarioScope $scope): void
     {
-        static::$tracer->hook($scope);
+        self::$tracer->hook($scope);
     }
 
     /**
      * @AfterSuite
      */
-    public static function clean(AfterSuiteScope $scope)
+    public static function clean(AfterSuiteScope $scope): void
     {
-        static::$tracer->hook($scope);
-        static::$tracer = null;
+        self::$tracer->hook($scope);
+        self::$tracer = null;
     }
 
     private RedmineInstance $redmine;
@@ -89,13 +89,13 @@ public function __construct(string $redmineVersion, string $rootPath)
             throw new InvalidArgumentException('Redmine ' . $redmineVersion . ' is not supported.');
         }
 
-        $this->redmine = static::$tracer::getRedmineInstance($version, $rootPath);
+        $this->redmine = self::$tracer::getRedmineInstance($version, $rootPath);
     }
 
     /**
      * @Given I have a :clientName client
      */
-    public function iHaveAClient($clientName)
+    public function iHaveAClient($clientName): void
     {
         if ($clientName !== 'NativeCurlClient') {
             throw new InvalidArgumentException('Client ' . $clientName . ' is not supported.');
@@ -122,7 +122,7 @@ private function registerClientResponse(mixed $lastReturn, Response $lastRespons
     /**
      * @Then the response has the status code :statusCode
      */
-    public function theResponseHasTheStatusCode(int $statusCode)
+    public function theResponseHasTheStatusCode(int $statusCode): void
     {
         TestCase::assertSame(
             $statusCode,
@@ -134,7 +134,7 @@ public function theResponseHasTheStatusCode(int $statusCode)
     /**
      * @Then the response has the content type :contentType
      */
-    public function theResponseHasTheContentType(string $contentType)
+    public function theResponseHasTheContentType(string $contentType): void
     {
         TestCase::assertStringStartsWith(
             $contentType,
@@ -146,7 +146,7 @@ public function theResponseHasTheContentType(string $contentType)
     /**
      * @Then the response has an empty content type
      */
-    public function theResponseHasAnEmptyContentType()
+    public function theResponseHasAnEmptyContentType(): void
     {
         TestCase::assertSame('', $this->lastResponse->getContentType());
     }
@@ -154,7 +154,7 @@ public function theResponseHasAnEmptyContentType()
     /**
      * @Then the response has the content :content
      */
-    public function theResponseHasTheContent(string $content)
+    public function theResponseHasTheContent(string $content): void
     {
         TestCase::assertSame($content, $this->lastResponse->getContent());
     }
@@ -162,7 +162,7 @@ public function theResponseHasTheContent(string $content)
     /**
      * @Then the response has the content
      */
-    public function theResponseHasTheContentWithMultipleLines(PyStringNode $string)
+    public function theResponseHasTheContentWithMultipleLines(PyStringNode $string): void
     {
         TestCase::assertSame($string->getRaw(), $this->lastResponse->getContent());
     }
@@ -170,7 +170,7 @@ public function theResponseHasTheContentWithMultipleLines(PyStringNode $string)
     /**
      * @Then the returned data is true
      */
-    public function theReturnedDataIsTrue()
+    public function theReturnedDataIsTrue(): void
     {
         TestCase::assertTrue($this->lastReturn);
     }
@@ -178,7 +178,7 @@ public function theReturnedDataIsTrue()
     /**
      * @Then the returned data is false
      */
-    public function theReturnedDataIsFalse()
+    public function theReturnedDataIsFalse(): void
     {
         TestCase::assertFalse($this->lastReturn);
     }
@@ -186,7 +186,7 @@ public function theReturnedDataIsFalse()
     /**
      * @Then the returned data is exactly :content
      */
-    public function theReturnedDataIsExactly(string $content)
+    public function theReturnedDataIsExactly(string $content): void
     {
         TestCase::assertSame($content, $this->lastReturn);
     }
@@ -194,7 +194,7 @@ public function theReturnedDataIsExactly(string $content)
     /**
      * @Then the returned data is exactly
      */
-    public function theReturnedDataIsExactlyWithMultipleLines(PyStringNode $string)
+    public function theReturnedDataIsExactlyWithMultipleLines(PyStringNode $string): void
     {
         TestCase::assertSame($string->getRaw(), $this->lastReturn);
     }
@@ -202,7 +202,7 @@ public function theReturnedDataIsExactlyWithMultipleLines(PyStringNode $string)
     /**
      * @Then the returned data is an instance of :className
      */
-    public function theReturnedDataIsAnInstanceOf(string $className)
+    public function theReturnedDataIsAnInstanceOf(string $className): void
     {
         TestCase::assertInstanceOf($className, $this->lastReturn);
     }
@@ -210,7 +210,7 @@ public function theReturnedDataIsAnInstanceOf(string $className)
     /**
      * @Then the returned data is an array
      */
-    public function theReturnedDataIsAnArray()
+    public function theReturnedDataIsAnArray(): void
     {
         TestCase::assertIsArray($this->lastReturn);
     }
@@ -218,7 +218,7 @@ public function theReturnedDataIsAnArray()
     /**
      * @Then the returned data contains :count items
      */
-    public function theReturnedDataContainsItems(int $count)
+    public function theReturnedDataContainsItems(int $count): void
     {
         TestCase::assertCount($count, $this->lastReturn);
     }
@@ -226,7 +226,7 @@ public function theReturnedDataContainsItems(int $count)
     /**
      * @Then the returned data contains the following data
      */
-    public function theReturnedDataContainsTheFollowingData(TableNode $table)
+    public function theReturnedDataContainsTheFollowingData(TableNode $table): void
     {
         $returnData = $this->lastReturn;
 
@@ -240,7 +240,7 @@ public function theReturnedDataContainsTheFollowingData(TableNode $table)
     /**
      * @Then the returned data has only the following properties
      */
-    public function theReturnedDataHasOnlyTheFollowingProperties(PyStringNode $string)
+    public function theReturnedDataHasOnlyTheFollowingProperties(PyStringNode $string): void
     {
         $this->theReturnedDataPropertyHasOnlyTheFollowingProperties(null, $string);
     }
@@ -248,7 +248,7 @@ public function theReturnedDataHasOnlyTheFollowingProperties(PyStringNode $strin
     /**
      * @Then the returned data has proterties with the following data
      */
-    public function theReturnedDataHasProtertiesWithTheFollowingData(TableNode $table)
+    public function theReturnedDataHasProtertiesWithTheFollowingData(TableNode $table): void
     {
         $this->theReturnedDataPropertyContainsTheFollowingData(null, $table);
     }
@@ -256,7 +256,7 @@ public function theReturnedDataHasProtertiesWithTheFollowingData(TableNode $tabl
     /**
      * @Then the returned data :property property is an array
      */
-    public function theReturnedDataPropertyIsAnArray($property)
+    public function theReturnedDataPropertyIsAnArray($property): void
     {
         $returnData = $this->getLastReturnAsArray();
 
@@ -268,7 +268,7 @@ public function theReturnedDataPropertyIsAnArray($property)
     /**
      * @Then the returned data :property property contains :count items
      */
-    public function theReturnedDataPropertyContainsItems($property, int $count)
+    public function theReturnedDataPropertyContainsItems($property, int $count): void
     {
         $returnData = $this->getLastReturnAsArray();
 
@@ -281,7 +281,7 @@ public function theReturnedDataPropertyContainsItems($property, int $count)
     /**
      * @Then the returned data :property property contains the following data
      */
-    public function theReturnedDataPropertyContainsTheFollowingData($property, TableNode $table)
+    public function theReturnedDataPropertyContainsTheFollowingData($property, TableNode $table): void
     {
         $returnData = $this->getItemFromArray($this->getLastReturnAsArray(), $property);
 
@@ -295,7 +295,7 @@ public function theReturnedDataPropertyContainsTheFollowingData($property, Table
     /**
      * @Then the returned data :property property contains the following data with Redmine version :versionComparision
      */
-    public function theReturnedDataPropertyContainsTheFollowingDataWithRedmineVersion($property, string $versionComparision, TableNode $table)
+    public function theReturnedDataPropertyContainsTheFollowingDataWithRedmineVersion($property, string $versionComparision, TableNode $table): void
     {
         $parts = explode(' ', $versionComparision);
 
@@ -313,7 +313,7 @@ public function theReturnedDataPropertyContainsTheFollowingDataWithRedmineVersio
     /**
      * @Then the returned data :property property has only the following properties
      */
-    public function theReturnedDataPropertyHasOnlyTheFollowingProperties($property, PyStringNode $string)
+    public function theReturnedDataPropertyHasOnlyTheFollowingProperties($property, PyStringNode $string): void
     {
         $value = $this->getItemFromArray($this->getLastReturnAsArray(), $property);
 
@@ -325,7 +325,7 @@ public function theReturnedDataPropertyHasOnlyTheFollowingProperties($property,
     /**
      * @Then the returned data :property property has only the following properties with Redmine version :versionComparision
      */
-    public function theReturnedDataPropertyHasOnlyTheFollowingPropertiesWithRedmineVersion($property, string $versionComparision, PyStringNode $string)
+    public function theReturnedDataPropertyHasOnlyTheFollowingPropertiesWithRedmineVersion($property, string $versionComparision, PyStringNode $string): void
     {
         $parts = explode(' ', $versionComparision);
 
@@ -388,7 +388,7 @@ private function getItemFromArray(array $array, $key): mixed
         return $array;
     }
 
-    private function assertTableNodeIsSameAsArray(TableNode $table, array $data)
+    private function assertTableNodeIsSameAsArray(TableNode $table, array $data): void
     {
         foreach ($table as $row) {
             TestCase::assertArrayHasKey($row['property'], $data, 'Possible keys are: ' . implode(', ', array_keys($data)));
diff --git a/tests/Fixtures/AssertingHttpClient.php b/tests/Fixtures/AssertingHttpClient.php
index cbafd365..52610a96 100644
--- a/tests/Fixtures/AssertingHttpClient.php
+++ b/tests/Fixtures/AssertingHttpClient.php
@@ -57,12 +57,12 @@ private function assertRequestData(
         int $responseCode = 200,
         string $responseContentType = '',
         string $responseContent = ''
-    ) {
+    ): void {
         if ($responseContentType === '') {
             $responseContentType = $contentType;
         }
 
-        array_push($this->fifoStack, [
+        $this->fifoStack[] = [
             'method' => $method,
             'path' => $path,
             'contentType' => $contentType,
@@ -70,7 +70,7 @@ private function assertRequestData(
             'responseCode' => $responseCode,
             'responseContentType' => $responseContentType,
             'responseContent' => $responseContent,
-        ]);
+        ];
     }
 
     public function request(Request $request): Response
diff --git a/tests/Fixtures/MockClient.php b/tests/Fixtures/MockClient.php
index 735e47d7..0a03b870 100644
--- a/tests/Fixtures/MockClient.php
+++ b/tests/Fixtures/MockClient.php
@@ -26,7 +26,7 @@ public static function create(): self
      *
      * @var mixed
      */
-    public $runRequestReturnValue = null;
+    public $runRequestReturnValue;
 
     /**
      * Return value the mocked runRequest method should return.
@@ -95,7 +95,7 @@ public function requestDelete(string $path): bool
      */
     public function getLastResponseStatusCode(): int
     {
-        return (int) $this->responseCodeMock;
+        return $this->responseCodeMock;
     }
 
     /**
@@ -103,7 +103,7 @@ public function getLastResponseStatusCode(): int
      */
     public function getLastResponseContentType(): string
     {
-        return (string) $this->responseContentTypeMock;
+        return $this->responseContentTypeMock;
     }
 
     /**
@@ -111,7 +111,7 @@ public function getLastResponseContentType(): string
      */
     public function getLastResponseBody(): string
     {
-        return (string) $this->responseBodyMock;
+        return $this->responseBodyMock;
     }
 
     private function runRequest(string $path, string $method = 'GET', string $data = ''): bool
diff --git a/tests/Integration/IssueCategoryXmlTest.php b/tests/Integration/IssueCategoryXmlTest.php
index 9b67f1a1..4b11e7d1 100644
--- a/tests/Integration/IssueCategoryXmlTest.php
+++ b/tests/Integration/IssueCategoryXmlTest.php
@@ -12,7 +12,7 @@ public function testCreateBlank(): void
     {
         /** @var \Redmine\Api\IssueCategory */
         $api = MockClient::create()->getApi('issue_category');
-        $this->assertInstanceOf('Redmine\Api\IssueCategory', $api);
+        $this->assertInstanceOf(\Redmine\Api\IssueCategory::class, $api);
 
         $this->expectException(MissingParameterException::class);
         $this->expectExceptionMessage('Theses parameters are mandatory: `name`');
diff --git a/tests/Integration/Psr18ClientRequestGenerationTest.php b/tests/Integration/Psr18ClientRequestGenerationTest.php
index 36008986..842cd05e 100644
--- a/tests/Integration/Psr18ClientRequestGenerationTest.php
+++ b/tests/Integration/Psr18ClientRequestGenerationTest.php
@@ -26,12 +26,12 @@ class Psr18ClientRequestGenerationTest extends TestCase
     public function testPsr18ClientCreatesCorrectRequests(
         string $url,
         string $apikeyOrUsername,
-        $pwd,
-        $impersonateUser,
+        ?string $pwd,
+        ?string $impersonateUser,
         string $method,
         string $path,
         $data,
-        $expectedOutput
+        string $expectedOutput
     ): void {
         $response = $this->createMock(ResponseInterface::class);
 
@@ -65,9 +65,7 @@ public function testPsr18ClientCreatesCorrectRequests(
         });
 
         $requestFactory = $this->createMock(RequestFactoryInterface::class);
-        $requestFactory->method('createRequest')->willReturnCallback(function ($method, $uri) {
-            return new Request($method, $uri);
-        });
+        $requestFactory->method('createRequest')->willReturnCallback(fn($method, $uri): \GuzzleHttp\Psr7\Request => new Request($method, $uri));
 
         $streamFactory = new class implements StreamFactoryInterface {
             public function createStream(string $content = ''): StreamInterface
diff --git a/tests/Integration/UserXmlTest.php b/tests/Integration/UserXmlTest.php
index ea17370c..23a97a1b 100644
--- a/tests/Integration/UserXmlTest.php
+++ b/tests/Integration/UserXmlTest.php
@@ -12,7 +12,7 @@ public function testCreateBlank(): void
     {
         /** @var \Redmine\Api\User */
         $api = MockClient::create()->getApi('user');
-        $this->assertInstanceOf('Redmine\Api\User', $api);
+        $this->assertInstanceOf(\Redmine\Api\User::class, $api);
 
         $this->expectException(MissingParameterException::class);
         $this->expectExceptionMessage('Theses parameters are mandatory: `login`, `lastname`, `firstname`, `mail`');
diff --git a/tests/RedmineExtension/BehatHookTracer.php b/tests/RedmineExtension/BehatHookTracer.php
index 04215442..75f422cf 100644
--- a/tests/RedmineExtension/BehatHookTracer.php
+++ b/tests/RedmineExtension/BehatHookTracer.php
@@ -24,45 +24,45 @@ final class BehatHookTracer implements InstanceRegistration
 
     public static function getRedmineInstance(RedmineVersion $redmineVersion, string $rootPath): RedmineInstance
     {
-        if (static::$tracer === null) {
+        if (!self::$tracer instanceof \Redmine\Tests\RedmineExtension\BehatHookTracer) {
             throw new RuntimeException('You can only get a Redmine instance while a Behat Suite is running.');
         }
 
-        if (! array_key_exists($redmineVersion->asId(), static::$instances)) {
-            RedmineInstance::create(static::$tracer, $redmineVersion, $rootPath);
+        if (! array_key_exists($redmineVersion->asId(), self::$instances)) {
+            RedmineInstance::create(self::$tracer, $redmineVersion, $rootPath);
         }
 
-        return static::$instances[$redmineVersion->asId()];
+        return self::$instances[$redmineVersion->asId()];
     }
 
     public function registerInstance(RedmineInstance $instance): void
     {
-        static::$instances[$instance->getVersionId()] = $instance;
+        self::$instances[$instance->getVersionId()] = $instance;
     }
 
     public function deregisterInstance(RedmineInstance $instance): void
     {
-        unset(static::$instances[$instance->getVersionId()]);
+        unset(self::$instances[$instance->getVersionId()]);
     }
 
     public function hook(HookScope $event): void
     {
         if ($event instanceof BeforeSuiteScope) {
-            static::$tracer = $this;
+            self::$tracer = $this;
         }
 
         if ($event instanceof AfterScenarioScope) {
-            foreach (static::$instances as $instance) {
+            foreach (self::$instances as $instance) {
                 $instance->reset($this);
             }
         }
 
         if ($event instanceof AfterSuiteScope) {
-            foreach (static::$instances as $instance) {
+            foreach (self::$instances as $instance) {
                 $instance->shutdown($this);
             }
 
-            static::$tracer = null;
+            self::$tracer = null;
         }
     }
 }
diff --git a/tests/RedmineExtension/RedmineInstance.php b/tests/RedmineExtension/RedmineInstance.php
index e5f52708..0e8c32b2 100644
--- a/tests/RedmineExtension/RedmineInstance.php
+++ b/tests/RedmineExtension/RedmineInstance.php
@@ -66,7 +66,7 @@ private function __construct(InstanceRegistration $tracer, RedmineVersion $versi
         $parts = explode('.', $version->asString());
 
         $this->redmineUrl = 'http://redmine-' . intval($parts[0]) . '-' . intval($parts[1]) . ':3000';
-        $this->apiKey = sha1($versionId . (string) time());
+        $this->apiKey = sha1($versionId . time());
 
         $this->runHealthChecks($version);
 
@@ -160,7 +160,7 @@ public function excecuteDatabaseQuery(string $query, array $options = [], ?array
         $stmt->execute($params);
     }
 
-    private function runDatabaseMigration()
+    private function runDatabaseMigration(): void
     {
         $now = new DateTimeImmutable();
         $pdo = new PDO('sqlite:' . $this->dataPath . $this->workingDB);
@@ -196,7 +196,7 @@ private function runDatabaseMigration()
     /**
      * Create backup of working database
      */
-    private function createDatabaseBackup()
+    private function createDatabaseBackup(): void
     {
         $workingDB = new SQLite3($this->dataPath . $this->workingDB);
 
@@ -211,7 +211,7 @@ private function createDatabaseBackup()
     /**
      * Create backup of migrated database
      */
-    private function saveMigratedDatabase()
+    private function saveMigratedDatabase(): void
     {
         $workingDB = new SQLite3($this->dataPath . $this->workingDB);
 
@@ -253,7 +253,7 @@ private function removeDatabaseBackups(): void
         unlink($this->dataPath . $this->backupDB);
     }
 
-    private function createFilesBackup()
+    private function createFilesBackup(): void
     {
         // Add an empty file to avoid warnings about copying and removing content from an empty folder
         touch($this->dataPath . $this->workingFiles . 'empty');
@@ -264,7 +264,7 @@ private function createFilesBackup()
         ));
     }
 
-    private function saveMigratedFiles()
+    private function saveMigratedFiles(): void
     {
         exec(sprintf(
             'cp -r %s %s',
diff --git a/tests/Unit/Api/AbstractApi/DeleteTest.php b/tests/Unit/Api/AbstractApi/DeleteTest.php
index 9df99358..a86460d0 100644
--- a/tests/Unit/Api/AbstractApi/DeleteTest.php
+++ b/tests/Unit/Api/AbstractApi/DeleteTest.php
@@ -45,7 +45,7 @@ public function testDeleteWithHttpClient(): void
      * @dataProvider getXmlDecodingFromDeleteMethodData
      */
     #[DataProvider('getXmlDecodingFromDeleteMethodData')]
-    public function testXmlDecodingFromDeleteMethod($response, $expected): void
+    public function testXmlDecodingFromDeleteMethod(string $response, string $expected): void
     {
         $client = $this->createMock(Client::class);
         $client->method('getLastResponseBody')->willReturn($response);
diff --git a/tests/Unit/Api/AbstractApi/GetTest.php b/tests/Unit/Api/AbstractApi/GetTest.php
index 3cf31e25..43f21085 100644
--- a/tests/Unit/Api/AbstractApi/GetTest.php
+++ b/tests/Unit/Api/AbstractApi/GetTest.php
@@ -47,7 +47,7 @@ public function testGetWithHttpClient(): void
      * @dataProvider getJsonDecodingFromGetMethodData
      */
     #[DataProvider('getJsonDecodingFromGetMethodData')]
-    public function testJsonDecodingFromGetMethod($response, $decode, $expected): void
+    public function testJsonDecodingFromGetMethod(string $response, ?bool $decode, $expected): void
     {
         $client = $this->createMock(Client::class);
         $client->method('getLastResponseBody')->willReturn($response);
@@ -82,7 +82,7 @@ public static function getJsonDecodingFromGetMethodData(): array
      * @dataProvider getXmlDecodingFromGetMethodData
      */
     #[DataProvider('getXmlDecodingFromGetMethodData')]
-    public function testXmlDecodingFromGetMethod($response, $decode, $expected): void
+    public function testXmlDecodingFromGetMethod(string $response, ?bool $decode, string $expected): void
     {
         $client = $this->createMock(Client::class);
         $client->method('getLastResponseBody')->willReturn($response);
diff --git a/tests/Unit/Api/AbstractApi/PostTest.php b/tests/Unit/Api/AbstractApi/PostTest.php
index d9b351af..adcb7161 100644
--- a/tests/Unit/Api/AbstractApi/PostTest.php
+++ b/tests/Unit/Api/AbstractApi/PostTest.php
@@ -47,7 +47,7 @@ public function testPostWithHttpClient(): void
      * @dataProvider getXmlDecodingFromPostMethodData
      */
     #[DataProvider('getXmlDecodingFromPostMethodData')]
-    public function testXmlDecodingFromPostMethod($response, $expected): void
+    public function testXmlDecodingFromPostMethod(string $response, string $expected): void
     {
         $client = $this->createMock(Client::class);
         $client->method('getLastResponseBody')->willReturn($response);
diff --git a/tests/Unit/Api/AbstractApi/PutTest.php b/tests/Unit/Api/AbstractApi/PutTest.php
index 9e262bd6..e6e80ef6 100644
--- a/tests/Unit/Api/AbstractApi/PutTest.php
+++ b/tests/Unit/Api/AbstractApi/PutTest.php
@@ -47,7 +47,7 @@ public function testPutWithHttpClient(): void
      * @dataProvider getXmlDecodingFromPutMethodData
      */
     #[DataProvider('getXmlDecodingFromPutMethodData')]
-    public function testXmlDecodingFromPutMethod($response, $expected): void
+    public function testXmlDecodingFromPutMethod(string $response, string $expected): void
     {
         $client = $this->createMock(Client::class);
         $client->method('getLastResponseBody')->willReturn($response);
diff --git a/tests/Unit/Api/AbstractApiTest.php b/tests/Unit/Api/AbstractApiTest.php
index d886960c..2c8a2896 100644
--- a/tests/Unit/Api/AbstractApiTest.php
+++ b/tests/Unit/Api/AbstractApiTest.php
@@ -257,7 +257,7 @@ public function __construct($client)
      * @dataProvider getLastCallFailedData
      */
     #[DataProvider('getLastCallFailedData')]
-    public function testLastCallFailedWithClientReturnsCorrectBoolean($statusCode, $expectedBoolean): void
+    public function testLastCallFailedWithClientReturnsCorrectBoolean(int $statusCode, bool $expectedBoolean): void
     {
         $client = $this->createMock(Client::class);
         $client->method('getLastResponseStatusCode')->willReturn($statusCode);
@@ -271,7 +271,7 @@ public function testLastCallFailedWithClientReturnsCorrectBoolean($statusCode, $
      * @dataProvider getLastCallFailedData
      */
     #[DataProvider('getLastCallFailedData')]
-    public function testLastCallFailedWithHttpClientReturnsCorrectBoolean($statusCode, $expectedBoolean): void
+    public function testLastCallFailedWithHttpClientReturnsCorrectBoolean(int $statusCode, bool $expectedBoolean): void
     {
         $response = $this->createMock(Response::class);
         $response->method('getStatusCode')->willReturn($statusCode);
@@ -365,7 +365,7 @@ public static function getLastCallFailedData(): array
      * @dataProvider retrieveDataData
      */
     #[DataProvider('retrieveDataData')]
-    public function testRetrieveData($path, $contentType, $response, $expected): void
+    public function testRetrieveData(string $path, string $contentType, string $response, array $expected): void
     {
         $client = $this->createMock(Client::class);
         $client->method('requestGet')->willReturn(true);
@@ -444,7 +444,7 @@ public function testRetrieveDataWith250ResultsMakes3Requests(): void
      * @dataProvider getRetrieveDataToExceptionData
      */
     #[DataProvider('getRetrieveDataToExceptionData')]
-    public function testRetrieveDataThrowsException($response, $contentType, $expectedException, $expectedMessage): void
+    public function testRetrieveDataThrowsException(string $response, string $contentType, string $expectedException, string $expectedMessage): void
     {
         $client = $this->createMock(Client::class);
         $client->method('requestGet')->willReturn(true);
@@ -473,7 +473,7 @@ public static function getRetrieveDataToExceptionData(): array
      * @dataProvider getRetrieveAllData
      */
     #[DataProvider('getRetrieveAllData')]
-    public function testDeprecatedRetrieveAll($content, $contentType, $expected): void
+    public function testDeprecatedRetrieveAll(string $content, string $contentType, $expected): void
     {
         $client = $this->createMock(Client::class);
         $client->method('requestGet')->willReturn(true);
diff --git a/tests/Unit/Api/Attachment/DownloadTest.php b/tests/Unit/Api/Attachment/DownloadTest.php
index cb3ab759..87301202 100644
--- a/tests/Unit/Api/Attachment/DownloadTest.php
+++ b/tests/Unit/Api/Attachment/DownloadTest.php
@@ -15,7 +15,7 @@ class DownloadTest extends TestCase
      * @dataProvider getDownloadData
      */
     #[DataProvider('getDownloadData')]
-    public function testDownloadReturnsCorrectResponse($id, $expectedPath, $responseCode, $response, $expectedReturn): void
+    public function testDownloadReturnsCorrectResponse($id, string $expectedPath, int $responseCode, string $response, $expectedReturn): void
     {
         $client = AssertingHttpClient::create(
             $this,
diff --git a/tests/Unit/Api/Attachment/ShowTest.php b/tests/Unit/Api/Attachment/ShowTest.php
index 37315559..c929b4e6 100644
--- a/tests/Unit/Api/Attachment/ShowTest.php
+++ b/tests/Unit/Api/Attachment/ShowTest.php
@@ -15,7 +15,7 @@ class ShowTest extends TestCase
      * @dataProvider getShowData
      */
     #[DataProvider('getShowData')]
-    public function testShowReturnsCorrectResponse($id, $expectedPath, $response, $expectedReturn): void
+    public function testShowReturnsCorrectResponse($id, string $expectedPath, string $response, $expectedReturn): void
     {
         $client = AssertingHttpClient::create(
             $this,
diff --git a/tests/Unit/Api/Attachment/UpdateTest.php b/tests/Unit/Api/Attachment/UpdateTest.php
index 8fd28190..02923902 100644
--- a/tests/Unit/Api/Attachment/UpdateTest.php
+++ b/tests/Unit/Api/Attachment/UpdateTest.php
@@ -16,7 +16,7 @@ class UpdateTest extends TestCase
      * @dataProvider getUpdateData
      */
     #[DataProvider('getUpdateData')]
-    public function testUpdateReturnsCorrectResponse($id, array $params, $expectedPath, $expectedContent, $expectedReturn): void
+    public function testUpdateReturnsCorrectResponse(int $id, array $params, string $expectedPath, string $expectedContent, bool $expectedReturn): void
     {
         $client = AssertingHttpClient::create(
             $this,
diff --git a/tests/Unit/Api/Attachment/UploadTest.php b/tests/Unit/Api/Attachment/UploadTest.php
index a86d9a0a..6f1d7540 100644
--- a/tests/Unit/Api/Attachment/UploadTest.php
+++ b/tests/Unit/Api/Attachment/UploadTest.php
@@ -15,7 +15,7 @@ class UploadTest extends TestCase
      * @dataProvider getUploadData
      */
     #[DataProvider('getUploadData')]
-    public function testUploadReturnsCorrectResponse($attachment, $params, $expectedAttachment, $expectedPath, $responseCode, $response, $expectedReturn): void
+    public function testUploadReturnsCorrectResponse(string $attachment, array $params, string $expectedAttachment, string $expectedPath, int $responseCode, string $response, string $expectedReturn): void
     {
         $client = AssertingHttpClient::create(
             $this,
diff --git a/tests/Unit/Api/AttachmentTest.php b/tests/Unit/Api/AttachmentTest.php
index a8f58fb3..a1ab9018 100644
--- a/tests/Unit/Api/AttachmentTest.php
+++ b/tests/Unit/Api/AttachmentTest.php
@@ -18,12 +18,9 @@ class AttachmentTest extends TestCase
      * Test lastCallFailed().
      *
      * @dataProvider responseCodeProvider
-     *
-     * @param int  $responseCode
-     * @param bool $hasFailed
      */
     #[DataProvider('responseCodeProvider')]
-    public function testLastCallFailedTrue($responseCode, $hasFailed): void
+    public function testLastCallFailedTrue(int $responseCode, bool $hasFailed): void
     {
         // Create the used mock objects
         $client = $this->createMock(Client::class);
diff --git a/tests/Unit/Api/CustomField/ListNamesTest.php b/tests/Unit/Api/CustomField/ListNamesTest.php
index 66c94041..36153176 100644
--- a/tests/Unit/Api/CustomField/ListNamesTest.php
+++ b/tests/Unit/Api/CustomField/ListNamesTest.php
@@ -17,7 +17,7 @@ class ListNamesTest extends TestCase
      * @dataProvider getListNamesData
      */
     #[DataProvider('getListNamesData')]
-    public function testListNamesReturnsCorrectResponse($expectedPath, $responseCode, $response, $expectedResponse): void
+    public function testListNamesReturnsCorrectResponse(string $expectedPath, int $responseCode, string $response, array $expectedResponse): void
     {
         $client = AssertingHttpClient::create(
             $this,
diff --git a/tests/Unit/Api/CustomFieldTest.php b/tests/Unit/Api/CustomFieldTest.php
index a713a7f9..6fd94f86 100644
--- a/tests/Unit/Api/CustomFieldTest.php
+++ b/tests/Unit/Api/CustomFieldTest.php
@@ -45,7 +45,7 @@ function ($errno, $errstr): bool {
      * @dataProvider getAllData
      */
     #[DataProvider('getAllData')]
-    public function testAllReturnsClientGetResponse($response, $responseType, $expectedResponse): void
+    public function testAllReturnsClientGetResponse(string $response, string $responseType, $expectedResponse): void
     {
         // Create the used mock objects
         $client = $this->createMock(Client::class);
@@ -151,12 +151,6 @@ public function testAllCallsEndpointUntilOffsetIsHigherThanTotalCount(): void
         // Test values
         $response = '{"limit":"100","offset":"10","total_count":"5","items":[]}';
         $allParameters = ['limit' => 250];
-        $returnDataSet = [
-            'limit' => '100',
-            'offset' => '10',
-            'total_count' => '5',
-            'items' => [],
-        ];
 
         // Create the used mock objects
         $client = $this->createMock(Client::class);
diff --git a/tests/Unit/Api/Group/AddUserTest.php b/tests/Unit/Api/Group/AddUserTest.php
index 7c85bfac..cfd15448 100644
--- a/tests/Unit/Api/Group/AddUserTest.php
+++ b/tests/Unit/Api/Group/AddUserTest.php
@@ -16,7 +16,7 @@ class AddUserTest extends TestCase
      * @dataProvider getAddUserData
      */
     #[DataProvider('getAddUserData')]
-    public function testAddUserReturnsCorrectResponse($groupId, $userId, $expectedPath, $expectedBody, $responseCode, $response): void
+    public function testAddUserReturnsCorrectResponse(int $groupId, int $userId, string $expectedPath, string $expectedBody, int $responseCode, string $response): void
     {
         $client = AssertingHttpClient::create(
             $this,
diff --git a/tests/Unit/Api/Group/CreateTest.php b/tests/Unit/Api/Group/CreateTest.php
index 800f1158..ae269f54 100644
--- a/tests/Unit/Api/Group/CreateTest.php
+++ b/tests/Unit/Api/Group/CreateTest.php
@@ -20,7 +20,7 @@ class CreateTest extends TestCase
      * @dataProvider getCreateData
      */
     #[DataProvider('getCreateData')]
-    public function testCreateReturnsCorrectResponse($parameters, $expectedPath, $expectedBody, $responseCode, $response): void
+    public function testCreateReturnsCorrectResponse(array $parameters, string $expectedPath, string $expectedBody, int $responseCode, string $response): void
     {
         $client = AssertingHttpClient::create(
             $this,
diff --git a/tests/Unit/Api/Group/ListNamesTest.php b/tests/Unit/Api/Group/ListNamesTest.php
index 3d952784..14b413b7 100644
--- a/tests/Unit/Api/Group/ListNamesTest.php
+++ b/tests/Unit/Api/Group/ListNamesTest.php
@@ -17,7 +17,7 @@ class ListNamesTest extends TestCase
      * @dataProvider getListNamesData
      */
     #[DataProvider('getListNamesData')]
-    public function testListNamesReturnsCorrectResponse($expectedPath, $responseCode, $response, $expectedResponse): void
+    public function testListNamesReturnsCorrectResponse(string $expectedPath, int $responseCode, string $response, array $expectedResponse): void
     {
         $client = AssertingHttpClient::create(
             $this,
diff --git a/tests/Unit/Api/Group/ShowTest.php b/tests/Unit/Api/Group/ShowTest.php
index 8bc8d12c..870c833a 100644
--- a/tests/Unit/Api/Group/ShowTest.php
+++ b/tests/Unit/Api/Group/ShowTest.php
@@ -15,7 +15,7 @@ class ShowTest extends TestCase
      * @dataProvider getShowData
      */
     #[DataProvider('getShowData')]
-    public function testShowReturnsCorrectResponse($groupId, array $params, $expectedPath, $response, $expectedReturn): void
+    public function testShowReturnsCorrectResponse($groupId, array $params, string $expectedPath, string $response, $expectedReturn): void
     {
         $client = AssertingHttpClient::create(
             $this,
diff --git a/tests/Unit/Api/Group/UpdateTest.php b/tests/Unit/Api/Group/UpdateTest.php
index e22de63d..d039e3ba 100644
--- a/tests/Unit/Api/Group/UpdateTest.php
+++ b/tests/Unit/Api/Group/UpdateTest.php
@@ -17,7 +17,7 @@ class UpdateTest extends TestCase
      * @dataProvider getUpdateData
      */
     #[DataProvider('getUpdateData')]
-    public function testUpdateReturnsCorrectResponse($id, $parameters, $expectedPath, $expectedBody, $responseCode, $response): void
+    public function testUpdateReturnsCorrectResponse(int $id, array $parameters, string $expectedPath, string $expectedBody, int $responseCode, string $response): void
     {
         $client = AssertingHttpClient::create(
             $this,
diff --git a/tests/Unit/Api/GroupTest.php b/tests/Unit/Api/GroupTest.php
index f3f35973..14d01398 100644
--- a/tests/Unit/Api/GroupTest.php
+++ b/tests/Unit/Api/GroupTest.php
@@ -47,7 +47,7 @@ function ($errno, $errstr): bool {
      * @dataProvider getAllData
      */
     #[DataProvider('getAllData')]
-    public function testAllReturnsClientGetResponse($response, $responseType, $expectedResponse): void
+    public function testAllReturnsClientGetResponse(string $response, string $responseType, $expectedResponse): void
     {
         // Create the used mock objects
         $client = $this->createMock(Client::class);
diff --git a/tests/Unit/Api/Issue/AddNoteToIssueTest.php b/tests/Unit/Api/Issue/AddNoteToIssueTest.php
index 771b3101..af5a9dc0 100644
--- a/tests/Unit/Api/Issue/AddNoteToIssueTest.php
+++ b/tests/Unit/Api/Issue/AddNoteToIssueTest.php
@@ -17,7 +17,7 @@ class AddNoteToIssueTest extends TestCase
      * @dataProvider getAddNoteToIssueData
      */
     #[DataProvider('getAddNoteToIssueData')]
-    public function testAddNoteToIssueReturnsCorrectResponse($id, $note, $isPrivate, $expectedPath, $expectedBody, $responseCode, $response): void
+    public function testAddNoteToIssueReturnsCorrectResponse(int $id, string $note, bool $isPrivate, string $expectedPath, string $expectedBody, int $responseCode, string $response): void
     {
         $client = AssertingHttpClient::create(
             $this,
diff --git a/tests/Unit/Api/Issue/AddWatcherTest.php b/tests/Unit/Api/Issue/AddWatcherTest.php
index 26fbda1c..868807e1 100644
--- a/tests/Unit/Api/Issue/AddWatcherTest.php
+++ b/tests/Unit/Api/Issue/AddWatcherTest.php
@@ -16,7 +16,7 @@ class AddWatcherTest extends TestCase
      * @dataProvider getAddWatcherData
      */
     #[DataProvider('getAddWatcherData')]
-    public function testAddWatcherReturnsCorrectResponse($issueId, $watcherUserId, $expectedPath, $expectedBody, $responseCode, $response): void
+    public function testAddWatcherReturnsCorrectResponse(int $issueId, int $watcherUserId, string $expectedPath, string $expectedBody, int $responseCode, string $response): void
     {
         $client = AssertingHttpClient::create(
             $this,
diff --git a/tests/Unit/Api/Issue/AttachManyTest.php b/tests/Unit/Api/Issue/AttachManyTest.php
index 038011ed..f88bf247 100644
--- a/tests/Unit/Api/Issue/AttachManyTest.php
+++ b/tests/Unit/Api/Issue/AttachManyTest.php
@@ -15,7 +15,7 @@ class AttachManyTest extends TestCase
      * @dataProvider getAttachManyData
      */
     #[DataProvider('getAttachManyData')]
-    public function testAttachManyReturnsCorrectResponse($issueId, $parameters, $expectedPath, $expectedBody, $responseCode, $response): void
+    public function testAttachManyReturnsCorrectResponse(int $issueId, array $parameters, string $expectedPath, string $expectedBody, int $responseCode, string $response): void
     {
         $client = AssertingHttpClient::create(
             $this,
diff --git a/tests/Unit/Api/Issue/AttachTest.php b/tests/Unit/Api/Issue/AttachTest.php
index 9cfce197..5ccd2641 100644
--- a/tests/Unit/Api/Issue/AttachTest.php
+++ b/tests/Unit/Api/Issue/AttachTest.php
@@ -15,7 +15,7 @@ class AttachTest extends TestCase
      * @dataProvider getAttachData
      */
     #[DataProvider('getAttachData')]
-    public function testAttachReturnsCorrectResponse($issueId, $parameters, $expectedPath, $expectedBody, $responseCode, $response): void
+    public function testAttachReturnsCorrectResponse(int $issueId, array $parameters, string $expectedPath, string $expectedBody, int $responseCode, string $response): void
     {
         $client = AssertingHttpClient::create(
             $this,
diff --git a/tests/Unit/Api/Issue/CreateTest.php b/tests/Unit/Api/Issue/CreateTest.php
index dd142481..09e1e1b9 100644
--- a/tests/Unit/Api/Issue/CreateTest.php
+++ b/tests/Unit/Api/Issue/CreateTest.php
@@ -16,7 +16,7 @@ class CreateTest extends TestCase
      * @dataProvider getCreateData
      */
     #[DataProvider('getCreateData')]
-    public function testCreateReturnsCorrectResponse($parameters, $expectedPath, $expectedBody, $responseCode, $response): void
+    public function testCreateReturnsCorrectResponse(array $parameters, string $expectedPath, string $expectedBody, int $responseCode, string $response): void
     {
         $client = AssertingHttpClient::create(
             $this,
diff --git a/tests/Unit/Api/Issue/RemoveTest.php b/tests/Unit/Api/Issue/RemoveTest.php
index cccf5b03..effe5f99 100644
--- a/tests/Unit/Api/Issue/RemoveTest.php
+++ b/tests/Unit/Api/Issue/RemoveTest.php
@@ -15,7 +15,7 @@ class RemoveTest extends TestCase
      * @dataProvider getRemoveData
      */
     #[DataProvider('getRemoveData')]
-    public function testRemoveReturnsCorrectResponse($issueId, $expectedPath, $responseCode, $response): void
+    public function testRemoveReturnsCorrectResponse(int $issueId, string $expectedPath, int $responseCode, string $response): void
     {
         $client = AssertingHttpClient::create(
             $this,
diff --git a/tests/Unit/Api/Issue/RemoveWatcherTest.php b/tests/Unit/Api/Issue/RemoveWatcherTest.php
index 1e8f9c4b..677ef505 100644
--- a/tests/Unit/Api/Issue/RemoveWatcherTest.php
+++ b/tests/Unit/Api/Issue/RemoveWatcherTest.php
@@ -15,7 +15,7 @@ class RemoveWatcherTest extends TestCase
      * @dataProvider getRemoveWatcherData
      */
     #[DataProvider('getRemoveWatcherData')]
-    public function testRemoveWatcherReturnsCorrectResponse($issueId, $watcherUserId, $expectedPath, $responseCode, $response): void
+    public function testRemoveWatcherReturnsCorrectResponse(int $issueId, int $watcherUserId, string $expectedPath, int $responseCode, string $response): void
     {
         $client = AssertingHttpClient::create(
             $this,
diff --git a/tests/Unit/Api/Issue/ShowTest.php b/tests/Unit/Api/Issue/ShowTest.php
index 45718e7a..5d206f62 100644
--- a/tests/Unit/Api/Issue/ShowTest.php
+++ b/tests/Unit/Api/Issue/ShowTest.php
@@ -15,7 +15,7 @@ class ShowTest extends TestCase
      * @dataProvider getShowData
      */
     #[DataProvider('getShowData')]
-    public function testShowReturnsCorrectResponse($issueId, array $params, $expectedPath, $response, $expectedReturn): void
+    public function testShowReturnsCorrectResponse($issueId, array $params, string $expectedPath, string $response, $expectedReturn): void
     {
         $client = AssertingHttpClient::create(
             $this,
diff --git a/tests/Unit/Api/Issue/UpdateTest.php b/tests/Unit/Api/Issue/UpdateTest.php
index d30fb1b7..f61c20d4 100644
--- a/tests/Unit/Api/Issue/UpdateTest.php
+++ b/tests/Unit/Api/Issue/UpdateTest.php
@@ -17,7 +17,7 @@ class UpdateTest extends TestCase
      * @dataProvider getUpdateData
      */
     #[DataProvider('getUpdateData')]
-    public function testUpdateReturnsCorrectResponse($id, $parameters, $expectedPath, $expectedBody, $responseCode, $response): void
+    public function testUpdateReturnsCorrectResponse(int $id, array $parameters, string $expectedPath, string $expectedBody, int $responseCode, string $response): void
     {
         $client = AssertingHttpClient::create(
             $this,
diff --git a/tests/Unit/Api/IssueCategory/CreateTest.php b/tests/Unit/Api/IssueCategory/CreateTest.php
index 5fe5365e..576d9be3 100644
--- a/tests/Unit/Api/IssueCategory/CreateTest.php
+++ b/tests/Unit/Api/IssueCategory/CreateTest.php
@@ -18,7 +18,7 @@ class CreateTest extends TestCase
      * @dataProvider getCreateData
      */
     #[DataProvider('getCreateData')]
-    public function testCreateReturnsCorrectResponse($identifier, $parameters, $expectedPath, $expectedBody, $responseCode, $response): void
+    public function testCreateReturnsCorrectResponse($identifier, array $parameters, string $expectedPath, string $expectedBody, int $responseCode, string $response): void
     {
         $client = AssertingHttpClient::create(
             $this,
@@ -116,7 +116,7 @@ public function testCreateThrowsExceptionWithEmptyParameters(): void
      * @dataProvider incompleteCreateParameterProvider
      */
     #[DataProvider('incompleteCreateParameterProvider')]
-    public function testCreateThrowsExceptionIfMandatoyParametersAreMissing($parameters): void
+    public function testCreateThrowsExceptionIfMandatoyParametersAreMissing(array $parameters): void
     {
         // Create the used mock objects
         $client = $this->createMock(HttpClient::class);
diff --git a/tests/Unit/Api/IssueCategory/ListNamesByProjectTest.php b/tests/Unit/Api/IssueCategory/ListNamesByProjectTest.php
index aae301c5..2640f277 100644
--- a/tests/Unit/Api/IssueCategory/ListNamesByProjectTest.php
+++ b/tests/Unit/Api/IssueCategory/ListNamesByProjectTest.php
@@ -21,7 +21,7 @@ class ListNamesByProjectTest extends TestCase
      * @dataProvider getListNamesByProjectData
      */
     #[DataProvider('getListNamesByProjectData')]
-    public function testListNamesByProjectReturnsCorrectResponse($projectIdentifier, $expectedPath, $responseCode, $response, $expectedResponse): void
+    public function testListNamesByProjectReturnsCorrectResponse($projectIdentifier, string $expectedPath, int $responseCode, string $response, array $expectedResponse): void
     {
         $client = AssertingHttpClient::create(
             $this,
diff --git a/tests/Unit/Api/IssueCategory/RemoveTest.php b/tests/Unit/Api/IssueCategory/RemoveTest.php
index f66d6e8f..42bfad30 100644
--- a/tests/Unit/Api/IssueCategory/RemoveTest.php
+++ b/tests/Unit/Api/IssueCategory/RemoveTest.php
@@ -15,7 +15,7 @@ class RemoveTest extends TestCase
      * @dataProvider getRemoveData
      */
     #[DataProvider('getRemoveData')]
-    public function testRemoveReturnsCorrectResponse($issueId, $params, $expectedPath, $responseCode, $response): void
+    public function testRemoveReturnsCorrectResponse(int $issueId, array $params, string $expectedPath, int $responseCode, string $response): void
     {
         $client = AssertingHttpClient::create(
             $this,
diff --git a/tests/Unit/Api/IssueCategory/ShowTest.php b/tests/Unit/Api/IssueCategory/ShowTest.php
index e9e5c960..59ce6fba 100644
--- a/tests/Unit/Api/IssueCategory/ShowTest.php
+++ b/tests/Unit/Api/IssueCategory/ShowTest.php
@@ -15,7 +15,7 @@ class ShowTest extends TestCase
      * @dataProvider getShowData
      */
     #[DataProvider('getShowData')]
-    public function testShowReturnsCorrectResponse($id, $expectedPath, $response, $expectedReturn): void
+    public function testShowReturnsCorrectResponse($id, string $expectedPath, string $response, $expectedReturn): void
     {
         $client = AssertingHttpClient::create(
             $this,
diff --git a/tests/Unit/Api/IssueCategory/UpdateTest.php b/tests/Unit/Api/IssueCategory/UpdateTest.php
index c948ed67..fc8f0d95 100644
--- a/tests/Unit/Api/IssueCategory/UpdateTest.php
+++ b/tests/Unit/Api/IssueCategory/UpdateTest.php
@@ -17,7 +17,7 @@ class UpdateTest extends TestCase
      * @dataProvider getUpdateData
      */
     #[DataProvider('getUpdateData')]
-    public function testUpdateReturnsCorrectResponse($id, $parameters, $expectedPath, $expectedBody, $responseCode, $response): void
+    public function testUpdateReturnsCorrectResponse(int $id, array $parameters, string $expectedPath, string $expectedBody, int $responseCode, string $response): void
     {
         $client = AssertingHttpClient::create(
             $this,
diff --git a/tests/Unit/Api/IssueCategoryTest.php b/tests/Unit/Api/IssueCategoryTest.php
index 0838502d..12d63b4e 100644
--- a/tests/Unit/Api/IssueCategoryTest.php
+++ b/tests/Unit/Api/IssueCategoryTest.php
@@ -45,7 +45,7 @@ function ($errno, $errstr): bool {
      * @dataProvider getAllDAta
      */
     #[DataProvider('getAllData')]
-    public function testAllReturnsClientGetResponseWithProject($response, $responseType, $expectedResponse): void
+    public function testAllReturnsClientGetResponseWithProject(string $response, string $responseType, $expectedResponse): void
     {
         // Test values
         $projectId = 5;
diff --git a/tests/Unit/Api/IssuePriorityTest.php b/tests/Unit/Api/IssuePriorityTest.php
index bb07580f..7363db9a 100644
--- a/tests/Unit/Api/IssuePriorityTest.php
+++ b/tests/Unit/Api/IssuePriorityTest.php
@@ -45,7 +45,7 @@ function ($errno, $errstr): bool {
      * @dataProvider getAllData
      */
     #[DataProvider('getAllData')]
-    public function testAllReturnsClientGetResponse($response, $responseType, $expectedResponse): void
+    public function testAllReturnsClientGetResponse(string $response, string $responseType, $expectedResponse): void
     {
         // Create the used mock objects
         $client = $this->createMock(Client::class);
diff --git a/tests/Unit/Api/IssueRelation/CreateTest.php b/tests/Unit/Api/IssueRelation/CreateTest.php
index d273fdc8..004d8edb 100644
--- a/tests/Unit/Api/IssueRelation/CreateTest.php
+++ b/tests/Unit/Api/IssueRelation/CreateTest.php
@@ -18,7 +18,7 @@ class CreateTest extends TestCase
      * @dataProvider getCreateData
      */
     #[DataProvider('getCreateData')]
-    public function testCreateReturnsCorrectResponse($issueId, $parameters, $expectedPath, $expectedBody, $responseCode, $response, $expectedReturn): void
+    public function testCreateReturnsCorrectResponse(int $issueId, array $parameters, string $expectedPath, string $expectedBody, int $responseCode, string $response, array $expectedReturn): void
     {
         $client = AssertingHttpClient::create(
             $this,
@@ -102,7 +102,7 @@ public function testCreateThrowsExceptionWithEmptyParameters(): void
      * @dataProvider incompleteCreateParameterProvider
      */
     #[DataProvider('incompleteCreateParameterProvider')]
-    public function testCreateThrowsExceptionIfMandatoyParametersAreMissing($parameters): void
+    public function testCreateThrowsExceptionIfMandatoyParametersAreMissing(array $parameters): void
     {
         // Create the used mock objects
         $client = $this->createMock(HttpClient::class);
diff --git a/tests/Unit/Api/IssueRelation/RemoveTest.php b/tests/Unit/Api/IssueRelation/RemoveTest.php
index b754e9e8..0068abfa 100644
--- a/tests/Unit/Api/IssueRelation/RemoveTest.php
+++ b/tests/Unit/Api/IssueRelation/RemoveTest.php
@@ -15,7 +15,7 @@ class RemoveTest extends TestCase
      * @dataProvider getRemoveData
      */
     #[DataProvider('getRemoveData')]
-    public function testRemoveReturnsCorrectResponse($issueId, $expectedPath, $responseCode, $response): void
+    public function testRemoveReturnsCorrectResponse(int $issueId, string $expectedPath, int $responseCode, string $response): void
     {
         $client = AssertingHttpClient::create(
             $this,
diff --git a/tests/Unit/Api/IssueRelation/ShowTest.php b/tests/Unit/Api/IssueRelation/ShowTest.php
index adf974e1..f3722d29 100644
--- a/tests/Unit/Api/IssueRelation/ShowTest.php
+++ b/tests/Unit/Api/IssueRelation/ShowTest.php
@@ -15,7 +15,7 @@ class ShowTest extends TestCase
      * @dataProvider getShowData
      */
     #[DataProvider('getShowData')]
-    public function testShowReturnsCorrectResponse($id, $expectedPath, $response, $expectedReturn): void
+    public function testShowReturnsCorrectResponse($id, string $expectedPath, string $response, array $expectedReturn): void
     {
         $client = AssertingHttpClient::create(
             $this,
diff --git a/tests/Unit/Api/IssueRelationTest.php b/tests/Unit/Api/IssueRelationTest.php
index 79639c9d..f744ce29 100644
--- a/tests/Unit/Api/IssueRelationTest.php
+++ b/tests/Unit/Api/IssueRelationTest.php
@@ -45,7 +45,7 @@ function ($errno, $errstr): bool {
      * @dataProvider getAllData
      */
     #[DataProvider('getAllData')]
-    public function testAllReturnsClientGetResponseWithProject($response, $responseType, $expectedResponse): void
+    public function testAllReturnsClientGetResponseWithProject(string $response, string $responseType, $expectedResponse): void
     {
         // Create the used mock objects
         $client = $this->createMock(Client::class);
diff --git a/tests/Unit/Api/IssueStatus/ListNamesTest.php b/tests/Unit/Api/IssueStatus/ListNamesTest.php
index b0e8f4a6..98789e13 100644
--- a/tests/Unit/Api/IssueStatus/ListNamesTest.php
+++ b/tests/Unit/Api/IssueStatus/ListNamesTest.php
@@ -17,7 +17,7 @@ class ListNamesTest extends TestCase
      * @dataProvider getListNamesData
      */
     #[DataProvider('getListNamesData')]
-    public function testListNamesReturnsCorrectResponse($expectedPath, $responseCode, $response, $expectedResponse): void
+    public function testListNamesReturnsCorrectResponse(string $expectedPath, int $responseCode, string $response, array $expectedResponse): void
     {
         $client = AssertingHttpClient::create(
             $this,
diff --git a/tests/Unit/Api/IssueStatusTest.php b/tests/Unit/Api/IssueStatusTest.php
index 93c42aa0..32a27bd5 100644
--- a/tests/Unit/Api/IssueStatusTest.php
+++ b/tests/Unit/Api/IssueStatusTest.php
@@ -45,7 +45,7 @@ function ($errno, $errstr): bool {
      * @dataProvider getAllData
      */
     #[DataProvider('getAllData')]
-    public function testAllReturnsClientGetResponse($response, $responseType, $expectedResponse): void
+    public function testAllReturnsClientGetResponse(string $response, string $responseType, $expectedResponse): void
     {
         // Create the used mock objects
         $client = $this->createMock(Client::class);
diff --git a/tests/Unit/Api/IssueTest.php b/tests/Unit/Api/IssueTest.php
index fd9b4660..cfddb4bc 100644
--- a/tests/Unit/Api/IssueTest.php
+++ b/tests/Unit/Api/IssueTest.php
@@ -40,7 +40,7 @@ public static function getPriorityConstantsData(): array
      * @dataProvider getPriorityConstantsData
      */
     #[DataProvider('getPriorityConstantsData')]
-    public function testPriorityConstants($expected, $value): void
+    public function testPriorityConstants(int $expected, int $value): void
     {
         $this->assertSame($expected, $value);
     }
@@ -75,7 +75,7 @@ function ($errno, $errstr): bool {
      * @dataProvider getAllData
      */
     #[DataProvider('getAllData')]
-    public function testAllReturnsClientGetResponse($response, $responseType, $expectedResponse): void
+    public function testAllReturnsClientGetResponse(string $response, string $responseType, $expectedResponse): void
     {
         // Create the used mock objects
         $client = $this->createMock(Client::class);
diff --git a/tests/Unit/Api/Membership/CreateTest.php b/tests/Unit/Api/Membership/CreateTest.php
index 9a5813cf..9473d818 100644
--- a/tests/Unit/Api/Membership/CreateTest.php
+++ b/tests/Unit/Api/Membership/CreateTest.php
@@ -18,7 +18,7 @@ class CreateTest extends TestCase
      * @dataProvider getCreateData
      */
     #[DataProvider('getCreateData')]
-    public function testCreateReturnsCorrectResponse($identifier, $parameters, $expectedPath, $expectedBody, $responseCode, $response): void
+    public function testCreateReturnsCorrectResponse(int $identifier, array $parameters, string $expectedPath, string $expectedBody, int $responseCode, string $response): void
     {
         $client = AssertingHttpClient::create(
             $this,
@@ -108,7 +108,7 @@ public function testCreateThrowsExceptionWithEmptyParameters(): void
      * @dataProvider incompleteCreateParameterProvider
      */
     #[DataProvider('incompleteCreateParameterProvider')]
-    public function testCreateThrowsExceptionIfMandatoyParametersAreMissing($parameters): void
+    public function testCreateThrowsExceptionIfMandatoyParametersAreMissing(array $parameters): void
     {
         // Create the used mock objects
         $client = $this->createMock(HttpClient::class);
diff --git a/tests/Unit/Api/Membership/RemoveMemberTest.php b/tests/Unit/Api/Membership/RemoveMemberTest.php
index 584c928b..495ea5d3 100644
--- a/tests/Unit/Api/Membership/RemoveMemberTest.php
+++ b/tests/Unit/Api/Membership/RemoveMemberTest.php
@@ -15,7 +15,7 @@ class RemoveMemberTest extends TestCase
      * @dataProvider getRemoveMemberData
      */
     #[DataProvider('getRemoveMemberData')]
-    public function testRemoveMemberReturnsCorrectResponse($projectIdentifier, $userId, array $params, $expectedPath, $responseCode, $response): void
+    public function testRemoveMemberReturnsCorrectResponse(int $projectIdentifier, int $userId, array $params, string $expectedPath, int $responseCode, string $response): void
     {
         $client = AssertingHttpClient::create(
             $this,
diff --git a/tests/Unit/Api/Membership/RemoveTest.php b/tests/Unit/Api/Membership/RemoveTest.php
index 57bf7338..b18f65b0 100644
--- a/tests/Unit/Api/Membership/RemoveTest.php
+++ b/tests/Unit/Api/Membership/RemoveTest.php
@@ -15,7 +15,7 @@ class RemoveTest extends TestCase
      * @dataProvider getRemoveData
      */
     #[DataProvider('getRemoveData')]
-    public function testRemoveReturnsCorrectResponse($id, $expectedPath, $responseCode, $response): void
+    public function testRemoveReturnsCorrectResponse(int $id, string $expectedPath, int $responseCode, string $response): void
     {
         $client = AssertingHttpClient::create(
             $this,
diff --git a/tests/Unit/Api/Membership/UpdateTest.php b/tests/Unit/Api/Membership/UpdateTest.php
index e8e498b6..92e348c8 100644
--- a/tests/Unit/Api/Membership/UpdateTest.php
+++ b/tests/Unit/Api/Membership/UpdateTest.php
@@ -17,7 +17,7 @@ class UpdateTest extends TestCase
      * @dataProvider getUpdateData
      */
     #[DataProvider('getUpdateData')]
-    public function testUpdateReturnsCorrectResponse($id, $parameters, $expectedPath, $expectedBody, $responseCode, $response): void
+    public function testUpdateReturnsCorrectResponse(int $id, array $parameters, string $expectedPath, string $expectedBody, int $responseCode, string $response): void
     {
         $client = AssertingHttpClient::create(
             $this,
@@ -105,7 +105,7 @@ public function testUpdateThrowsExceptionWithEmptyParameters(): void
      * @dataProvider incompleteUpdateParameterProvider
      */
     #[DataProvider('incompleteUpdateParameterProvider')]
-    public function testUpdateThrowsExceptionIfMandatoyParametersAreMissing($parameters): void
+    public function testUpdateThrowsExceptionIfMandatoyParametersAreMissing(array $parameters): void
     {
         // Create the used mock objects
         $client = $this->createMock(HttpClient::class);
diff --git a/tests/Unit/Api/MembershipTest.php b/tests/Unit/Api/MembershipTest.php
index 28b1e463..70af3a16 100644
--- a/tests/Unit/Api/MembershipTest.php
+++ b/tests/Unit/Api/MembershipTest.php
@@ -45,7 +45,7 @@ function ($errno, $errstr): bool {
      * @dataProvider getAllData
      */
     #[DataProvider('getAllData')]
-    public function testAllReturnsClientGetResponseWithProject($response, $responseType, $expectedResponse): void
+    public function testAllReturnsClientGetResponseWithProject(string $response, string $responseType, $expectedResponse): void
     {
         // Create the used mock objects
         $client = $this->createMock(Client::class);
diff --git a/tests/Unit/Api/NewsTest.php b/tests/Unit/Api/NewsTest.php
index 1d26f327..32b589f4 100644
--- a/tests/Unit/Api/NewsTest.php
+++ b/tests/Unit/Api/NewsTest.php
@@ -45,7 +45,7 @@ function ($errno, $errstr): bool {
      * @dataProvider getAllData
      */
     #[DataProvider('getAllData')]
-    public function testAllReturnsClientGetResponse($response, $responseType, $expectedResponse): void
+    public function testAllReturnsClientGetResponse(string $response, string $responseType, $expectedResponse): void
     {
         // Create the used mock objects
         $client = $this->createMock(Client::class);
diff --git a/tests/Unit/Api/Project/CreateTest.php b/tests/Unit/Api/Project/CreateTest.php
index bb7b2ab8..c44e398c 100644
--- a/tests/Unit/Api/Project/CreateTest.php
+++ b/tests/Unit/Api/Project/CreateTest.php
@@ -18,7 +18,7 @@ class CreateTest extends TestCase
      * @dataProvider getCreateData
      */
     #[DataProvider('getCreateData')]
-    public function testCreateReturnsCorrectResponse($parameters, $expectedPath, $expectedBody, $responseCode, $response): void
+    public function testCreateReturnsCorrectResponse(array $parameters, string $expectedPath, string $expectedBody, int $responseCode, string $response): void
     {
         $client = AssertingHttpClient::create(
             $this,
@@ -174,7 +174,7 @@ public function testCreateThrowsExceptionWithEmptyParameters(): void
      * @dataProvider incompleteCreateParameterProvider
      */
     #[DataProvider('incompleteCreateParameterProvider')]
-    public function testCreateThrowsExceptionIfMandatoyParametersAreMissing($parameters): void
+    public function testCreateThrowsExceptionIfMandatoyParametersAreMissing(array $parameters): void
     {
         // Create the used mock objects
         $client = $this->createMock(HttpClient::class);
diff --git a/tests/Unit/Api/Project/ListNamesTest.php b/tests/Unit/Api/Project/ListNamesTest.php
index 57e7dc99..44136945 100644
--- a/tests/Unit/Api/Project/ListNamesTest.php
+++ b/tests/Unit/Api/Project/ListNamesTest.php
@@ -17,7 +17,7 @@ class ListNamesTest extends TestCase
      * @dataProvider getListNamesData
      */
     #[DataProvider('getListNamesData')]
-    public function testListNamesReturnsCorrectResponse($expectedPath, $responseCode, $response, $expectedResponse): void
+    public function testListNamesReturnsCorrectResponse(string $expectedPath, int $responseCode, string $response, array $expectedResponse): void
     {
         $client = AssertingHttpClient::create(
             $this,
diff --git a/tests/Unit/Api/Project/RemoveTest.php b/tests/Unit/Api/Project/RemoveTest.php
index 048a857d..0a1c38c5 100644
--- a/tests/Unit/Api/Project/RemoveTest.php
+++ b/tests/Unit/Api/Project/RemoveTest.php
@@ -15,7 +15,7 @@ class RemoveTest extends TestCase
      * @dataProvider getRemoveData
      */
     #[DataProvider('getRemoveData')]
-    public function testRemoveReturnsCorrectResponse($id, $expectedPath, $responseCode, $response): void
+    public function testRemoveReturnsCorrectResponse(int $id, string $expectedPath, int $responseCode, string $response): void
     {
         $client = AssertingHttpClient::create(
             $this,
diff --git a/tests/Unit/Api/Project/ShowTest.php b/tests/Unit/Api/Project/ShowTest.php
index a1685e65..fb7ea5c9 100644
--- a/tests/Unit/Api/Project/ShowTest.php
+++ b/tests/Unit/Api/Project/ShowTest.php
@@ -15,7 +15,7 @@ class ShowTest extends TestCase
      * @dataProvider getShowData
      */
     #[DataProvider('getShowData')]
-    public function testShowReturnsCorrectResponse($identifier, array $params, $expectedPath, $response, $expectedReturn): void
+    public function testShowReturnsCorrectResponse($identifier, array $params, string $expectedPath, string $response, $expectedReturn): void
     {
         $client = AssertingHttpClient::create(
             $this,
diff --git a/tests/Unit/Api/Project/UpdateTest.php b/tests/Unit/Api/Project/UpdateTest.php
index 2328d467..5f12e417 100644
--- a/tests/Unit/Api/Project/UpdateTest.php
+++ b/tests/Unit/Api/Project/UpdateTest.php
@@ -17,7 +17,7 @@ class UpdateTest extends TestCase
      * @dataProvider getUpdateData
      */
     #[DataProvider('getUpdateData')]
-    public function testUpdateReturnsCorrectResponse($id, $parameters, $expectedPath, $expectedBody, $responseCode, $response): void
+    public function testUpdateReturnsCorrectResponse(int $id, array $parameters, string $expectedPath, string $expectedBody, int $responseCode, string $response): void
     {
         $client = AssertingHttpClient::create(
             $this,
diff --git a/tests/Unit/Api/ProjectTest.php b/tests/Unit/Api/ProjectTest.php
index 468b05d1..a100c14f 100644
--- a/tests/Unit/Api/ProjectTest.php
+++ b/tests/Unit/Api/ProjectTest.php
@@ -47,7 +47,7 @@ function ($errno, $errstr): bool {
      * @dataProvider getAllData
      */
     #[DataProvider('getAllData')]
-    public function testAllReturnsClientGetResponse($response, $responseType, $expectedResponse): void
+    public function testAllReturnsClientGetResponse(string $response, string $responseType, $expectedResponse): void
     {
         // Create the used mock objects
         $client = $this->createMock(Client::class);
diff --git a/tests/Unit/Api/QueryTest.php b/tests/Unit/Api/QueryTest.php
index 22c8a158..86af788c 100644
--- a/tests/Unit/Api/QueryTest.php
+++ b/tests/Unit/Api/QueryTest.php
@@ -45,7 +45,7 @@ function ($errno, $errstr): bool {
      * @dataProvider getAllData
      */
     #[DataProvider('getAllData')]
-    public function testAllReturnsClientGetResponse($response, $responseType, $expectedResponse): void
+    public function testAllReturnsClientGetResponse(string $response, string $responseType, $expectedResponse): void
     {
         // Create the used mock objects
         $client = $this->createMock(Client::class);
diff --git a/tests/Unit/Api/Role/ListNamesTest.php b/tests/Unit/Api/Role/ListNamesTest.php
index c304cd97..aa849d73 100644
--- a/tests/Unit/Api/Role/ListNamesTest.php
+++ b/tests/Unit/Api/Role/ListNamesTest.php
@@ -17,7 +17,7 @@ class ListNamesTest extends TestCase
      * @dataProvider getListNamesData
      */
     #[DataProvider('getListNamesData')]
-    public function testListNamesReturnsCorrectResponse($expectedPath, $responseCode, $response, $expectedResponse): void
+    public function testListNamesReturnsCorrectResponse(string $expectedPath, int $responseCode, string $response, array $expectedResponse): void
     {
         $client = AssertingHttpClient::create(
             $this,
diff --git a/tests/Unit/Api/Role/ShowTest.php b/tests/Unit/Api/Role/ShowTest.php
index 10de7af7..5da8e4e8 100644
--- a/tests/Unit/Api/Role/ShowTest.php
+++ b/tests/Unit/Api/Role/ShowTest.php
@@ -15,7 +15,7 @@ class ShowTest extends TestCase
      * @dataProvider getShowData
      */
     #[DataProvider('getShowData')]
-    public function testShowReturnsCorrectResponse($id, $expectedPath, $response, $expectedReturn): void
+    public function testShowReturnsCorrectResponse($id, string $expectedPath, string $response, $expectedReturn): void
     {
         $client = AssertingHttpClient::create(
             $this,
diff --git a/tests/Unit/Api/RoleTest.php b/tests/Unit/Api/RoleTest.php
index f49f7d8c..e11ec6d9 100644
--- a/tests/Unit/Api/RoleTest.php
+++ b/tests/Unit/Api/RoleTest.php
@@ -45,7 +45,7 @@ function ($errno, $errstr): bool {
      * @dataProvider getAllData
      */
     #[DataProvider('getAllData')]
-    public function testAllReturnsClientGetResponse($response, $responseType, $expectedResponse): void
+    public function testAllReturnsClientGetResponse(string $response, string $responseType, $expectedResponse): void
     {
         // Create the used mock objects
         $client = $this->createMock(Client::class);
diff --git a/tests/Unit/Api/Search/SearchTest.php b/tests/Unit/Api/Search/SearchTest.php
index 22b953d3..5756a619 100644
--- a/tests/Unit/Api/Search/SearchTest.php
+++ b/tests/Unit/Api/Search/SearchTest.php
@@ -37,7 +37,7 @@ function ($errno, $errstr): bool {
      * @dataProvider getAllData
      */
     #[DataProvider('getAllData')]
-    public function testSearchReturnsClientGetResponse($response, $responseType, $expectedResponse): void
+    public function testSearchReturnsClientGetResponse(string $response, string $responseType, $expectedResponse): void
     {
         // Create the used mock objects
         $client = $this->createMock(Client::class);
diff --git a/tests/Unit/Api/TimeEntry/CreateTest.php b/tests/Unit/Api/TimeEntry/CreateTest.php
index 79225dc7..821afdb3 100644
--- a/tests/Unit/Api/TimeEntry/CreateTest.php
+++ b/tests/Unit/Api/TimeEntry/CreateTest.php
@@ -18,7 +18,7 @@ class CreateTest extends TestCase
      * @dataProvider getCreateData
      */
     #[DataProvider('getCreateData')]
-    public function testCreateReturnsCorrectResponse($parameters, $expectedPath, $expectedBody, $responseCode, $response): void
+    public function testCreateReturnsCorrectResponse(array $parameters, string $expectedPath, string $expectedBody, int $responseCode, string $response): void
     {
         $client = AssertingHttpClient::create(
             $this,
@@ -149,7 +149,7 @@ public function testCreateThrowsExceptionWithEmptyParameters(): void
      * @dataProvider incompleteCreateParameterProvider
      */
     #[DataProvider('incompleteCreateParameterProvider')]
-    public function testCreateThrowsExceptionIfValueIsMissingInParameters($parameters): void
+    public function testCreateThrowsExceptionIfValueIsMissingInParameters(array $parameters): void
     {
         // Create the used mock objects
         $client = $this->createMock(HttpClient::class);
diff --git a/tests/Unit/Api/TimeEntry/RemoveTest.php b/tests/Unit/Api/TimeEntry/RemoveTest.php
index fedc10f0..e5d71965 100644
--- a/tests/Unit/Api/TimeEntry/RemoveTest.php
+++ b/tests/Unit/Api/TimeEntry/RemoveTest.php
@@ -15,7 +15,7 @@ class RemoveTest extends TestCase
      * @dataProvider getRemoveData
      */
     #[DataProvider('getRemoveData')]
-    public function testRemoveReturnsCorrectResponse($id, $expectedPath, $responseCode, $response): void
+    public function testRemoveReturnsCorrectResponse(int $id, string $expectedPath, int $responseCode, string $response): void
     {
         $client = AssertingHttpClient::create(
             $this,
diff --git a/tests/Unit/Api/TimeEntry/ShowTest.php b/tests/Unit/Api/TimeEntry/ShowTest.php
index 3dd3d737..414d90ac 100644
--- a/tests/Unit/Api/TimeEntry/ShowTest.php
+++ b/tests/Unit/Api/TimeEntry/ShowTest.php
@@ -15,7 +15,7 @@ class ShowTest extends TestCase
      * @dataProvider getShowData
      */
     #[DataProvider('getShowData')]
-    public function testShowReturnsCorrectResponse($id, $expectedPath, $response, $expectedReturn): void
+    public function testShowReturnsCorrectResponse($id, string $expectedPath, string $response, $expectedReturn): void
     {
         $client = AssertingHttpClient::create(
             $this,
diff --git a/tests/Unit/Api/TimeEntry/UpdateTest.php b/tests/Unit/Api/TimeEntry/UpdateTest.php
index aebccee8..05e77d88 100644
--- a/tests/Unit/Api/TimeEntry/UpdateTest.php
+++ b/tests/Unit/Api/TimeEntry/UpdateTest.php
@@ -17,7 +17,7 @@ class UpdateTest extends TestCase
      * @dataProvider getUpdateData
      */
     #[DataProvider('getUpdateData')]
-    public function testUpdateReturnsCorrectResponse($id, $parameters, $expectedPath, $expectedBody, $responseCode, $response): void
+    public function testUpdateReturnsCorrectResponse(int $id, array $parameters, string $expectedPath, string $expectedBody, int $responseCode, string $response): void
     {
         $client = AssertingHttpClient::create(
             $this,
diff --git a/tests/Unit/Api/TimeEntryActivity/ListNamesTest.php b/tests/Unit/Api/TimeEntryActivity/ListNamesTest.php
index 9f60c1bb..7172ef9b 100644
--- a/tests/Unit/Api/TimeEntryActivity/ListNamesTest.php
+++ b/tests/Unit/Api/TimeEntryActivity/ListNamesTest.php
@@ -17,7 +17,7 @@ class ListNamesTest extends TestCase
      * @dataProvider getListNamesData
      */
     #[DataProvider('getListNamesData')]
-    public function testListNamesReturnsCorrectResponse($expectedPath, $responseCode, $response, $expectedResponse): void
+    public function testListNamesReturnsCorrectResponse(string $expectedPath, int $responseCode, string $response, array $expectedResponse): void
     {
         $client = AssertingHttpClient::create(
             $this,
diff --git a/tests/Unit/Api/TimeEntryActivityTest.php b/tests/Unit/Api/TimeEntryActivityTest.php
index cd687797..1a9450ee 100644
--- a/tests/Unit/Api/TimeEntryActivityTest.php
+++ b/tests/Unit/Api/TimeEntryActivityTest.php
@@ -45,7 +45,7 @@ function ($errno, $errstr): bool {
      * @dataProvider getAllData
      */
     #[DataProvider('getAllData')]
-    public function testAllReturnsClientGetResponse($response, $responseType, $expectedResponse): void
+    public function testAllReturnsClientGetResponse(string $response, string $responseType, $expectedResponse): void
     {
         // Create the used mock objects
         $client = $this->createMock(Client::class);
diff --git a/tests/Unit/Api/TimeEntryTest.php b/tests/Unit/Api/TimeEntryTest.php
index 965ce4f7..c53ce120 100644
--- a/tests/Unit/Api/TimeEntryTest.php
+++ b/tests/Unit/Api/TimeEntryTest.php
@@ -45,7 +45,7 @@ function ($errno, $errstr): bool {
      * @dataProvider getAllData
      */
     #[DataProvider('getAllData')]
-    public function testAllReturnsClientGetResponse($response, $responseType, $expectedResponse): void
+    public function testAllReturnsClientGetResponse(string $response, string $responseType, $expectedResponse): void
     {
         // Create the used mock objects
         $client = $this->createMock(Client::class);
diff --git a/tests/Unit/Api/Tracker/ListNamesTest.php b/tests/Unit/Api/Tracker/ListNamesTest.php
index cbd4cdb4..d962eec9 100644
--- a/tests/Unit/Api/Tracker/ListNamesTest.php
+++ b/tests/Unit/Api/Tracker/ListNamesTest.php
@@ -17,7 +17,7 @@ class ListNamesTest extends TestCase
      * @dataProvider getListNamesData
      */
     #[DataProvider('getListNamesData')]
-    public function testListNamesReturnsCorrectResponse($expectedPath, $responseCode, $response, $expectedResponse): void
+    public function testListNamesReturnsCorrectResponse(string $expectedPath, int $responseCode, string $response, array $expectedResponse): void
     {
         $client = AssertingHttpClient::create(
             $this,
diff --git a/tests/Unit/Api/TrackerTest.php b/tests/Unit/Api/TrackerTest.php
index 72a8c7e7..54dd54a0 100644
--- a/tests/Unit/Api/TrackerTest.php
+++ b/tests/Unit/Api/TrackerTest.php
@@ -45,7 +45,7 @@ function ($errno, $errstr): bool {
      * @dataProvider getAllData
      */
     #[DataProvider('getAllData')]
-    public function testAllReturnsClientGetResponse($response, $responseType, $expectedResponse): void
+    public function testAllReturnsClientGetResponse(string $response, string $responseType, $expectedResponse): void
     {
         // Create the used mock objects
         $client = $this->createMock(Client::class);
diff --git a/tests/Unit/Api/User/CreateTest.php b/tests/Unit/Api/User/CreateTest.php
index c1abfbf5..538864a7 100644
--- a/tests/Unit/Api/User/CreateTest.php
+++ b/tests/Unit/Api/User/CreateTest.php
@@ -18,7 +18,7 @@ class CreateTest extends TestCase
      * @dataProvider getCreateData
      */
     #[DataProvider('getCreateData')]
-    public function testCreateReturnsCorrectResponse($parameters, $expectedPath, $expectedBody, $responseCode, $response): void
+    public function testCreateReturnsCorrectResponse(array $parameters, string $expectedPath, string $expectedBody, int $responseCode, string $response): void
     {
         $client = AssertingHttpClient::create(
             $this,
@@ -136,7 +136,7 @@ public function testCreateThrowsExceptionWithEmptyParameters(): void
      * @dataProvider incompleteCreateParameterProvider
      */
     #[DataProvider('incompleteCreateParameterProvider')]
-    public function testCreateThrowsExceptionIfValueIsMissingInParameters($parameters): void
+    public function testCreateThrowsExceptionIfValueIsMissingInParameters(array $parameters): void
     {
         // Create the used mock objects
         $client = $this->createMock(HttpClient::class);
diff --git a/tests/Unit/Api/User/ListLoginsTest.php b/tests/Unit/Api/User/ListLoginsTest.php
index c9a530f0..6aa2a463 100644
--- a/tests/Unit/Api/User/ListLoginsTest.php
+++ b/tests/Unit/Api/User/ListLoginsTest.php
@@ -17,7 +17,7 @@ class ListLoginsTest extends TestCase
      * @dataProvider getListLoginsData
      */
     #[DataProvider('getListLoginsData')]
-    public function testListLoginsReturnsCorrectResponse($expectedPath, $responseCode, $response, $expectedResponse): void
+    public function testListLoginsReturnsCorrectResponse(string $expectedPath, int $responseCode, string $response, array $expectedResponse): void
     {
         $client = AssertingHttpClient::create(
             $this,
diff --git a/tests/Unit/Api/User/RemoveTest.php b/tests/Unit/Api/User/RemoveTest.php
index 84ae9967..ed20489c 100644
--- a/tests/Unit/Api/User/RemoveTest.php
+++ b/tests/Unit/Api/User/RemoveTest.php
@@ -15,7 +15,7 @@ class RemoveTest extends TestCase
      * @dataProvider getRemoveData
      */
     #[DataProvider('getRemoveData')]
-    public function testRemoveReturnsCorrectResponse($id, $expectedPath, $responseCode, $response): void
+    public function testRemoveReturnsCorrectResponse(int $id, string $expectedPath, int $responseCode, string $response): void
     {
         $client = AssertingHttpClient::create(
             $this,
diff --git a/tests/Unit/Api/User/ShowTest.php b/tests/Unit/Api/User/ShowTest.php
index e872c025..eb4fbfcf 100644
--- a/tests/Unit/Api/User/ShowTest.php
+++ b/tests/Unit/Api/User/ShowTest.php
@@ -15,7 +15,7 @@ class ShowTest extends TestCase
      * @dataProvider getShowData
      */
     #[DataProvider('getShowData')]
-    public function testShowReturnsCorrectResponse($userId, array $params, $expectedPath, $response, $expectedReturn): void
+    public function testShowReturnsCorrectResponse($userId, array $params, string $expectedPath, string $response, $expectedReturn): void
     {
         $client = AssertingHttpClient::create(
             $this,
diff --git a/tests/Unit/Api/User/UpdateTest.php b/tests/Unit/Api/User/UpdateTest.php
index 32d0a66a..7d1d2df6 100644
--- a/tests/Unit/Api/User/UpdateTest.php
+++ b/tests/Unit/Api/User/UpdateTest.php
@@ -17,7 +17,7 @@ class UpdateTest extends TestCase
      * @dataProvider getUpdateData
      */
     #[DataProvider('getUpdateData')]
-    public function testUpdateReturnsCorrectResponse($id, $parameters, $expectedPath, $expectedBody, $responseCode, $response): void
+    public function testUpdateReturnsCorrectResponse(int $id, array $parameters, string $expectedPath, string $expectedBody, int $responseCode, string $response): void
     {
         $client = AssertingHttpClient::create(
             $this,
diff --git a/tests/Unit/Api/UserTest.php b/tests/Unit/Api/UserTest.php
index 5eec179c..b76f8176 100644
--- a/tests/Unit/Api/UserTest.php
+++ b/tests/Unit/Api/UserTest.php
@@ -142,7 +142,7 @@ function ($errno, $errstr): bool {
      * @dataProvider getAllData
      */
     #[DataProvider('getAllData')]
-    public function testAllReturnsClientGetResponse($response, $responseType, $expectedResponse): void
+    public function testAllReturnsClientGetResponse(string $response, string $responseType, $expectedResponse): void
     {
         // Create the used mock objects
         $client = $this->createMock(Client::class);
diff --git a/tests/Unit/Api/Version/CreateTest.php b/tests/Unit/Api/Version/CreateTest.php
index 9c8428b3..7632e805 100644
--- a/tests/Unit/Api/Version/CreateTest.php
+++ b/tests/Unit/Api/Version/CreateTest.php
@@ -19,7 +19,7 @@ class CreateTest extends TestCase
      * @dataProvider getCreateData
      */
     #[DataProvider('getCreateData')]
-    public function testCreateReturnsCorrectResponse($identifier, $parameters, $expectedPath, $expectedBody, $responseCode, $response): void
+    public function testCreateReturnsCorrectResponse(int $identifier, array $parameters, string $expectedPath, string $expectedBody, int $responseCode, string $response): void
     {
         $client = AssertingHttpClient::create(
             $this,
diff --git a/tests/Unit/Api/Version/ListNamesByProjectTest.php b/tests/Unit/Api/Version/ListNamesByProjectTest.php
index ea343ef1..2281727a 100644
--- a/tests/Unit/Api/Version/ListNamesByProjectTest.php
+++ b/tests/Unit/Api/Version/ListNamesByProjectTest.php
@@ -21,7 +21,7 @@ class ListNamesByProjectTest extends TestCase
      * @dataProvider getListNamesByProjectData
      */
     #[DataProvider('getListNamesByProjectData')]
-    public function testListNamesByProjectReturnsCorrectResponse($projectIdentifier, $expectedPath, $responseCode, $response, $expectedResponse): void
+    public function testListNamesByProjectReturnsCorrectResponse($projectIdentifier, string $expectedPath, int $responseCode, string $response, array $expectedResponse): void
     {
         $client = AssertingHttpClient::create(
             $this,
diff --git a/tests/Unit/Api/Version/RemoveTest.php b/tests/Unit/Api/Version/RemoveTest.php
index 2fe1c212..b9b3f9bc 100644
--- a/tests/Unit/Api/Version/RemoveTest.php
+++ b/tests/Unit/Api/Version/RemoveTest.php
@@ -15,7 +15,7 @@ class RemoveTest extends TestCase
      * @dataProvider getRemoveData
      */
     #[DataProvider('getRemoveData')]
-    public function testRemoveReturnsCorrectResponse($id, $expectedPath, $responseCode, $response): void
+    public function testRemoveReturnsCorrectResponse($id, string $expectedPath, int $responseCode, string $response): void
     {
         $client = AssertingHttpClient::create(
             $this,
diff --git a/tests/Unit/Api/Version/ShowTest.php b/tests/Unit/Api/Version/ShowTest.php
index 73da9055..1cc98cbd 100644
--- a/tests/Unit/Api/Version/ShowTest.php
+++ b/tests/Unit/Api/Version/ShowTest.php
@@ -15,7 +15,7 @@ class ShowTest extends TestCase
      * @dataProvider getShowData
      */
     #[DataProvider('getShowData')]
-    public function testShowReturnsCorrectResponse($version, $expectedPath, $response, $expectedReturn): void
+    public function testShowReturnsCorrectResponse($version, string $expectedPath, string $response, $expectedReturn): void
     {
         $client = AssertingHttpClient::create(
             $this,
diff --git a/tests/Unit/Api/Version/UpdateTest.php b/tests/Unit/Api/Version/UpdateTest.php
index 5b55302e..60253ded 100644
--- a/tests/Unit/Api/Version/UpdateTest.php
+++ b/tests/Unit/Api/Version/UpdateTest.php
@@ -17,7 +17,7 @@ class UpdateTest extends TestCase
      * @dataProvider getUpdateData
      */
     #[DataProvider('getUpdateData')]
-    public function testUpdateReturnsCorrectResponse($id, $parameters, $expectedPath, $expectedBody, $responseCode, $response): void
+    public function testUpdateReturnsCorrectResponse(int $id, array $parameters, string $expectedPath, string $expectedBody, int $responseCode, string $response): void
     {
         $client = AssertingHttpClient::create(
             $this,
diff --git a/tests/Unit/Api/VersionTest.php b/tests/Unit/Api/VersionTest.php
index 48033fab..1ab3fd59 100644
--- a/tests/Unit/Api/VersionTest.php
+++ b/tests/Unit/Api/VersionTest.php
@@ -46,7 +46,7 @@ function ($errno, $errstr): bool {
      * @dataProvider getAllData
      */
     #[DataProvider('getAllData')]
-    public function testAllReturnsClientGetResponse($response, $responseType, $expectedResponse): void
+    public function testAllReturnsClientGetResponse(string $response, string $responseType, $expectedResponse): void
     {
         // Create the used mock objects
         $client = $this->createMock(Client::class);
@@ -342,11 +342,9 @@ function ($errno, $errstr): bool {
      * Test validateSharing().
      *
      * @dataProvider      invalidSharingProvider
-     *
-     * @param string $sharingValue
      */
     #[DataProvider('invalidSharingProvider')]
-    public function testCreateThrowsExceptionWithInvalidSharing($sharingValue): void
+    public function testCreateThrowsExceptionWithInvalidSharing(string $sharingValue): void
     {
         // Test values
         $parameters = [
diff --git a/tests/Unit/Api/Wiki/CreateTest.php b/tests/Unit/Api/Wiki/CreateTest.php
index ebf9eda3..0bb30561 100644
--- a/tests/Unit/Api/Wiki/CreateTest.php
+++ b/tests/Unit/Api/Wiki/CreateTest.php
@@ -18,7 +18,7 @@ class CreateTest extends TestCase
      * @dataProvider getCreateData
      */
     #[DataProvider('getCreateData')]
-    public function testCreateReturnsCorrectResponse($id, $page, $parameters, $expectedPath, $expectedBody, $responseCode, $response): void
+    public function testCreateReturnsCorrectResponse(int $id, string $page, array $parameters, string $expectedPath, string $expectedBody, int $responseCode, string $response): void
     {
         $client = AssertingHttpClient::create(
             $this,
diff --git a/tests/Unit/Api/Wiki/RemoveTest.php b/tests/Unit/Api/Wiki/RemoveTest.php
index 51bb3019..981d6462 100644
--- a/tests/Unit/Api/Wiki/RemoveTest.php
+++ b/tests/Unit/Api/Wiki/RemoveTest.php
@@ -17,7 +17,7 @@ class RemoveTest extends TestCase
      * @dataProvider getRemoveData
      */
     #[DataProvider('getRemoveData')]
-    public function testRemoveReturnsCorrectResponse($id, $page, $expectedPath, $responseCode, $response): void
+    public function testRemoveReturnsCorrectResponse(int $id, string $page, string $expectedPath, int $responseCode, string $response): void
     {
         $client = AssertingHttpClient::create(
             $this,
diff --git a/tests/Unit/Api/Wiki/ShowTest.php b/tests/Unit/Api/Wiki/ShowTest.php
index 75ef788e..3ab8a1a4 100644
--- a/tests/Unit/Api/Wiki/ShowTest.php
+++ b/tests/Unit/Api/Wiki/ShowTest.php
@@ -15,7 +15,7 @@ class ShowTest extends TestCase
      * @dataProvider getShowData
      */
     #[DataProvider('getShowData')]
-    public function testShowReturnsCorrectResponse($identifier, $page, $version, $expectedPath, $response, $expectedReturn): void
+    public function testShowReturnsCorrectResponse($identifier, string $page, ?int $version, string $expectedPath, string $response, $expectedReturn): void
     {
         $client = AssertingHttpClient::create(
             $this,
diff --git a/tests/Unit/Api/Wiki/UpdateTest.php b/tests/Unit/Api/Wiki/UpdateTest.php
index 923012d2..23126761 100644
--- a/tests/Unit/Api/Wiki/UpdateTest.php
+++ b/tests/Unit/Api/Wiki/UpdateTest.php
@@ -17,7 +17,7 @@ class UpdateTest extends TestCase
      * @dataProvider getUpdateData
      */
     #[DataProvider('getUpdateData')]
-    public function testUpdateReturnsCorrectResponse($id, $page, $parameters, $expectedPath, $expectedBody, $responseCode, $response): void
+    public function testUpdateReturnsCorrectResponse(int $id, string $page, array $parameters, string $expectedPath, string $expectedBody, int $responseCode, string $response): void
     {
         $client = AssertingHttpClient::create(
             $this,
diff --git a/tests/Unit/Api/WikiTest.php b/tests/Unit/Api/WikiTest.php
index 9c487efa..ff907bf4 100644
--- a/tests/Unit/Api/WikiTest.php
+++ b/tests/Unit/Api/WikiTest.php
@@ -45,7 +45,7 @@ function ($errno, $errstr): bool {
      * @dataProvider getAllData
      */
     #[DataProvider('getAllData')]
-    public function testAllReturnsClientGetResponse($response, $responseType, $expectedResponse): void
+    public function testAllReturnsClientGetResponse(string $response, string $responseType, $expectedResponse): void
     {
         // Create the used mock objects
         $client = $this->createMock(Client::class);
diff --git a/tests/Unit/Client/NativeCurlClient/RequestTest.php b/tests/Unit/Client/NativeCurlClient/RequestTest.php
index 05c25177..869c9e59 100644
--- a/tests/Unit/Client/NativeCurlClient/RequestTest.php
+++ b/tests/Unit/Client/NativeCurlClient/RequestTest.php
@@ -20,7 +20,7 @@ class RequestTest extends TestCase
      * @dataProvider getRequestReponseData
      */
     #[DataProvider('getRequestReponseData')]
-    public function testRequestReturnsCorrectResponse($method, $data, $statusCode, $contentType, $content): void
+    public function testRequestReturnsCorrectResponse(string $method, string $data, int $statusCode, string $contentType, string $content): void
     {
         $namespace = 'Redmine\Client';
 
@@ -32,7 +32,7 @@ public function testRequestReturnsCorrectResponse($method, $data, $statusCode, $
         $curlExec = $this->getFunctionMock($namespace, 'curl_exec');
         $curlExec->expects($this->exactly(1))->willReturn($content);
 
-        $curlSetoptArray = $this->getFunctionMock($namespace, 'curl_setopt_array');
+        $this->getFunctionMock($namespace, 'curl_setopt_array');
 
         $curlGetinfo = $this->getFunctionMock($namespace, 'curl_getinfo');
         $curlGetinfo->expects($this->exactly(2))->willReturnMap(([
@@ -43,7 +43,7 @@ public function testRequestReturnsCorrectResponse($method, $data, $statusCode, $
         $curlErrno = $this->getFunctionMock($namespace, 'curl_errno');
         $curlErrno->expects($this->exactly(1))->willReturn(CURLE_OK);
 
-        $curlClose = $this->getFunctionMock($namespace, 'curl_close');
+        $this->getFunctionMock($namespace, 'curl_close');
 
         $client = new NativeCurlClient(
             'http://test.local',
@@ -105,7 +105,7 @@ public function testRequestWithUploadAndFilepathReturnsCorrectResponse(): void
         $curlExec = $this->getFunctionMock($namespace, 'curl_exec');
         $curlExec->expects($this->exactly(1))->willReturn('{"upload":{}}');
 
-        $curlSetoptArray = $this->getFunctionMock($namespace, 'curl_setopt_array');
+        $this->getFunctionMock($namespace, 'curl_setopt_array');
 
         $curlGetinfo = $this->getFunctionMock($namespace, 'curl_getinfo');
         $curlGetinfo->expects($this->exactly(2))->willReturnMap(([
@@ -116,7 +116,7 @@ public function testRequestWithUploadAndFilepathReturnsCorrectResponse(): void
         $curlErrno = $this->getFunctionMock($namespace, 'curl_errno');
         $curlErrno->expects($this->exactly(1))->willReturn(CURLE_OK);
 
-        $curlClose = $this->getFunctionMock($namespace, 'curl_close');
+        $this->getFunctionMock($namespace, 'curl_close');
 
         $client = new NativeCurlClient(
             'http://test.local',
diff --git a/tests/Unit/Client/NativeCurlClientTest.php b/tests/Unit/Client/NativeCurlClientTest.php
index c229db48..139e8f0d 100644
--- a/tests/Unit/Client/NativeCurlClientTest.php
+++ b/tests/Unit/Client/NativeCurlClientTest.php
@@ -204,7 +204,7 @@ public function testStartAndStopImpersonateUser(): void
         $curlErrno = $this->getFunctionMock(self::__NAMESPACE__, 'curl_errno');
         $curlErrno->expects($this->exactly(3))->willReturn(0);
 
-        $curlClose = $this->getFunctionMock(self::__NAMESPACE__, 'curl_close');
+        $this->getFunctionMock(self::__NAMESPACE__, 'curl_close');
 
         $client = new NativeCurlClient(
             'http://test.local',
@@ -259,7 +259,7 @@ public function testSetSslVersion(): void
         $curlErrno = $this->getFunctionMock(self::__NAMESPACE__, 'curl_errno');
         $curlErrno->expects($this->exactly(3))->willReturn(0);
 
-        $curlClose = $this->getFunctionMock(self::__NAMESPACE__, 'curl_close');
+        $this->getFunctionMock(self::__NAMESPACE__, 'curl_close');
 
         $client = new NativeCurlClient(
             'http://test.local',
@@ -315,7 +315,7 @@ public function testSetSslVerifypeer(): void
         $curlErrno = $this->getFunctionMock(self::__NAMESPACE__, 'curl_errno');
         $curlErrno->expects($this->exactly(3))->willReturn(0);
 
-        $curlClose = $this->getFunctionMock(self::__NAMESPACE__, 'curl_close');
+        $this->getFunctionMock(self::__NAMESPACE__, 'curl_close');
 
         $client = new NativeCurlClient(
             'http://test.local',
@@ -371,7 +371,7 @@ public function testSetSslVerifyhost(): void
         $curlErrno = $this->getFunctionMock(self::__NAMESPACE__, 'curl_errno');
         $curlErrno->expects($this->exactly(3))->willReturn(0);
 
-        $curlClose = $this->getFunctionMock(self::__NAMESPACE__, 'curl_close');
+        $this->getFunctionMock(self::__NAMESPACE__, 'curl_close');
 
         $client = new NativeCurlClient(
             'http://test.local',
@@ -428,7 +428,7 @@ public function testSetCustomHttpHeaders(): void
         $curlErrno = $this->getFunctionMock(self::__NAMESPACE__, 'curl_errno');
         $curlErrno->expects($this->exactly(3))->willReturn(0);
 
-        $curlClose = $this->getFunctionMock(self::__NAMESPACE__, 'curl_close');
+        $this->getFunctionMock(self::__NAMESPACE__, 'curl_close');
 
         $client = new NativeCurlClient(
             'http://test.local',
@@ -489,7 +489,7 @@ public function testSetCustomHost(): void
         $curlErrno = $this->getFunctionMock(self::__NAMESPACE__, 'curl_errno');
         $curlErrno->expects($this->exactly(3))->willReturn(0);
 
-        $curlClose = $this->getFunctionMock(self::__NAMESPACE__, 'curl_close');
+        $this->getFunctionMock(self::__NAMESPACE__, 'curl_close');
 
         $client = new NativeCurlClient(
             'http://test.local',
@@ -546,7 +546,7 @@ public function testSetPort(): void
         $curlErrno = $this->getFunctionMock(self::__NAMESPACE__, 'curl_errno');
         $curlErrno->expects($this->exactly(3))->willReturn(0);
 
-        $curlClose = $this->getFunctionMock(self::__NAMESPACE__, 'curl_close');
+        $this->getFunctionMock(self::__NAMESPACE__, 'curl_close');
 
         $client = new NativeCurlClient(
             'http://test.local',
@@ -600,7 +600,7 @@ public function testCustomPortWillSetFromSchema(): void
         $curlErrno = $this->getFunctionMock(self::__NAMESPACE__, 'curl_errno');
         $curlErrno->expects($this->exactly(1))->willReturn(0);
 
-        $curlClose = $this->getFunctionMock(self::__NAMESPACE__, 'curl_close');
+        $this->getFunctionMock(self::__NAMESPACE__, 'curl_close');
 
         $client = new NativeCurlClient(
             'https://test.local',
@@ -650,7 +650,7 @@ public function testCustomPortWillSetFromUrl(): void
         $curlErrno = $this->getFunctionMock(self::__NAMESPACE__, 'curl_errno');
         $curlErrno->expects($this->exactly(1))->willReturn(0);
 
-        $curlClose = $this->getFunctionMock(self::__NAMESPACE__, 'curl_close');
+        $this->getFunctionMock(self::__NAMESPACE__, 'curl_close');
 
         $client = new NativeCurlClient(
             'http://test.local:3456',
@@ -664,7 +664,7 @@ public function testCustomPortWillSetFromUrl(): void
      * @dataProvider getRequestReponseData
      */
     #[DataProvider('getRequestReponseData')]
-    public function testRequestsReturnsCorrectContent($method, $data, $boolReturn, $statusCode, $contentType, $content): void
+    public function testRequestsReturnsCorrectContent(string $method, string $data, bool $boolReturn, int $statusCode, string $contentType, string $content): void
     {
         $curl = $this->createMock(stdClass::class);
 
@@ -674,7 +674,7 @@ public function testRequestsReturnsCorrectContent($method, $data, $boolReturn, $
         $curlExec = $this->getFunctionMock(self::__NAMESPACE__, 'curl_exec');
         $curlExec->expects($this->exactly(1))->willReturn($content);
 
-        $curlSetoptArray = $this->getFunctionMock(self::__NAMESPACE__, 'curl_setopt_array');
+        $this->getFunctionMock(self::__NAMESPACE__, 'curl_setopt_array');
 
         $curlGetinfo = $this->getFunctionMock(self::__NAMESPACE__, 'curl_getinfo');
         $curlGetinfo->expects($this->exactly(2))->willReturnMap(([
@@ -685,7 +685,7 @@ public function testRequestsReturnsCorrectContent($method, $data, $boolReturn, $
         $curlErrno = $this->getFunctionMock(self::__NAMESPACE__, 'curl_errno');
         $curlErrno->expects($this->exactly(1))->willReturn(CURLE_OK);
 
-        $curlClose = $this->getFunctionMock(self::__NAMESPACE__, 'curl_close');
+        $this->getFunctionMock(self::__NAMESPACE__, 'curl_close');
 
         $client = new NativeCurlClient(
             'http://test.local',
@@ -726,23 +726,17 @@ public static function getRequestReponseData(): array
 
     public function testRequestGetTriggersDeprecationWarning(): void
     {
-        $curl = $this->createMock(stdClass::class);
-
-        $curlInit = $this->getFunctionMock(self::__NAMESPACE__, 'curl_init');
-
-        $curlExec = $this->getFunctionMock(self::__NAMESPACE__, 'curl_exec');
-
-        $curlSetoptArray = $this->getFunctionMock(self::__NAMESPACE__, 'curl_setopt_array');
-
-        $curlGetinfo = $this->getFunctionMock(self::__NAMESPACE__, 'curl_getinfo');
-
+        $this->getFunctionMock(self::__NAMESPACE__, 'curl_init');
+        $this->getFunctionMock(self::__NAMESPACE__, 'curl_exec');
+        $this->getFunctionMock(self::__NAMESPACE__, 'curl_setopt_array');
+        $this->getFunctionMock(self::__NAMESPACE__, 'curl_getinfo');
         $curlErrno = $this->getFunctionMock(self::__NAMESPACE__, 'curl_errno');
         $curlErrno->expects($this->exactly(1))->willReturn(CURLE_COULDNT_CONNECT);
 
         $curlError = $this->getFunctionMock(self::__NAMESPACE__, 'curl_error');
         $curlError->expects($this->exactly(1))->willReturn('');
 
-        $curlClose = $this->getFunctionMock(self::__NAMESPACE__, 'curl_close');
+        $this->getFunctionMock(self::__NAMESPACE__, 'curl_close');
 
         $client = new NativeCurlClient(
             'http://test.local',
@@ -771,23 +765,17 @@ function ($errno, $errstr): bool {
 
     public function testRequestPostTriggersDeprecationWarning(): void
     {
-        $curl = $this->createMock(stdClass::class);
-
-        $curlInit = $this->getFunctionMock(self::__NAMESPACE__, 'curl_init');
-
-        $curlExec = $this->getFunctionMock(self::__NAMESPACE__, 'curl_exec');
-
-        $curlSetoptArray = $this->getFunctionMock(self::__NAMESPACE__, 'curl_setopt_array');
-
-        $curlGetinfo = $this->getFunctionMock(self::__NAMESPACE__, 'curl_getinfo');
-
+        $this->getFunctionMock(self::__NAMESPACE__, 'curl_init');
+        $this->getFunctionMock(self::__NAMESPACE__, 'curl_exec');
+        $this->getFunctionMock(self::__NAMESPACE__, 'curl_setopt_array');
+        $this->getFunctionMock(self::__NAMESPACE__, 'curl_getinfo');
         $curlErrno = $this->getFunctionMock(self::__NAMESPACE__, 'curl_errno');
         $curlErrno->expects($this->exactly(1))->willReturn(CURLE_COULDNT_CONNECT);
 
         $curlError = $this->getFunctionMock(self::__NAMESPACE__, 'curl_error');
         $curlError->expects($this->exactly(1))->willReturn('');
 
-        $curlClose = $this->getFunctionMock(self::__NAMESPACE__, 'curl_close');
+        $this->getFunctionMock(self::__NAMESPACE__, 'curl_close');
 
         $client = new NativeCurlClient(
             'http://test.local',
@@ -816,23 +804,17 @@ function ($errno, $errstr): bool {
 
     public function testRequestPutTriggersDeprecationWarning(): void
     {
-        $curl = $this->createMock(stdClass::class);
-
-        $curlInit = $this->getFunctionMock(self::__NAMESPACE__, 'curl_init');
-
-        $curlExec = $this->getFunctionMock(self::__NAMESPACE__, 'curl_exec');
-
-        $curlSetoptArray = $this->getFunctionMock(self::__NAMESPACE__, 'curl_setopt_array');
-
-        $curlGetinfo = $this->getFunctionMock(self::__NAMESPACE__, 'curl_getinfo');
-
+        $this->getFunctionMock(self::__NAMESPACE__, 'curl_init');
+        $this->getFunctionMock(self::__NAMESPACE__, 'curl_exec');
+        $this->getFunctionMock(self::__NAMESPACE__, 'curl_setopt_array');
+        $this->getFunctionMock(self::__NAMESPACE__, 'curl_getinfo');
         $curlErrno = $this->getFunctionMock(self::__NAMESPACE__, 'curl_errno');
         $curlErrno->expects($this->exactly(1))->willReturn(CURLE_COULDNT_CONNECT);
 
         $curlError = $this->getFunctionMock(self::__NAMESPACE__, 'curl_error');
         $curlError->expects($this->exactly(1))->willReturn('');
 
-        $curlClose = $this->getFunctionMock(self::__NAMESPACE__, 'curl_close');
+        $this->getFunctionMock(self::__NAMESPACE__, 'curl_close');
 
         $client = new NativeCurlClient(
             'http://test.local',
@@ -861,23 +843,17 @@ function ($errno, $errstr): bool {
 
     public function testRequestDeleteTriggersDeprecationWarning(): void
     {
-        $curl = $this->createMock(stdClass::class);
-
-        $curlInit = $this->getFunctionMock(self::__NAMESPACE__, 'curl_init');
-
-        $curlExec = $this->getFunctionMock(self::__NAMESPACE__, 'curl_exec');
-
-        $curlSetoptArray = $this->getFunctionMock(self::__NAMESPACE__, 'curl_setopt_array');
-
-        $curlGetinfo = $this->getFunctionMock(self::__NAMESPACE__, 'curl_getinfo');
-
+        $this->getFunctionMock(self::__NAMESPACE__, 'curl_init');
+        $this->getFunctionMock(self::__NAMESPACE__, 'curl_exec');
+        $this->getFunctionMock(self::__NAMESPACE__, 'curl_setopt_array');
+        $this->getFunctionMock(self::__NAMESPACE__, 'curl_getinfo');
         $curlErrno = $this->getFunctionMock(self::__NAMESPACE__, 'curl_errno');
         $curlErrno->expects($this->exactly(1))->willReturn(CURLE_COULDNT_CONNECT);
 
         $curlError = $this->getFunctionMock(self::__NAMESPACE__, 'curl_error');
         $curlError->expects($this->exactly(1))->willReturn('');
 
-        $curlClose = $this->getFunctionMock(self::__NAMESPACE__, 'curl_close');
+        $this->getFunctionMock(self::__NAMESPACE__, 'curl_close');
 
         $client = new NativeCurlClient(
             'http://test.local',
@@ -918,7 +894,7 @@ public function testHandlingOfResponseWithoutContent(): void
         $curlExec = $this->getFunctionMock(self::__NAMESPACE__, 'curl_exec');
         $curlExec->expects($this->exactly(1))->willReturn('');
 
-        $curlSetoptArray = $this->getFunctionMock(self::__NAMESPACE__, 'curl_setopt_array');
+        $this->getFunctionMock(self::__NAMESPACE__, 'curl_setopt_array');
 
         $curlGetinfo = $this->getFunctionMock(self::__NAMESPACE__, 'curl_getinfo');
         $curlGetinfo->expects($this->exactly(2))->willReturnMap(([
@@ -929,7 +905,7 @@ public function testHandlingOfResponseWithoutContent(): void
         $curlErrno = $this->getFunctionMock(self::__NAMESPACE__, 'curl_errno');
         $curlErrno->expects($this->exactly(1))->willReturn(CURLE_OK);
 
-        $curlClose = $this->getFunctionMock(self::__NAMESPACE__, 'curl_close');
+        $this->getFunctionMock(self::__NAMESPACE__, 'curl_close');
 
         $client = new NativeCurlClient(
             'http://test.local',
@@ -952,7 +928,7 @@ public function testCurlErrorThrowsException(): void
         $curlExec = $this->getFunctionMock(self::__NAMESPACE__, 'curl_exec');
         $curlExec->expects($this->exactly(1))->willReturn(false);
 
-        $curlSetoptArray = $this->getFunctionMock(self::__NAMESPACE__, 'curl_setopt_array');
+        $this->getFunctionMock(self::__NAMESPACE__, 'curl_setopt_array');
 
         $curlErrno = $this->getFunctionMock(self::__NAMESPACE__, 'curl_errno');
         $curlErrno->expects($this->exactly(1))->willReturn(CURLE_URL_MALFORMAT);
@@ -960,7 +936,7 @@ public function testCurlErrorThrowsException(): void
         $curlError = $this->getFunctionMock(self::__NAMESPACE__, 'curl_error');
         $curlError->expects($this->exactly(1))->willReturn('cURL error 3: <url> malformed');
 
-        $curlClose = $this->getFunctionMock(self::__NAMESPACE__, 'curl_close');
+        $this->getFunctionMock(self::__NAMESPACE__, 'curl_close');
 
         $client = new NativeCurlClient(
             'http://test.local',
@@ -990,25 +966,25 @@ public function testGetApiShouldReturnApiInstance(string $apiName, string $class
     public static function getApiClassesProvider(): array
     {
         return [
-            ['attachment', 'Redmine\Api\Attachment'],
-            ['group', 'Redmine\Api\Group'],
-            ['custom_fields', 'Redmine\Api\CustomField'],
-            ['issue', 'Redmine\Api\Issue'],
-            ['issue_category', 'Redmine\Api\IssueCategory'],
-            ['issue_priority', 'Redmine\Api\IssuePriority'],
-            ['issue_relation', 'Redmine\Api\IssueRelation'],
-            ['issue_status', 'Redmine\Api\IssueStatus'],
-            ['membership', 'Redmine\Api\Membership'],
-            ['news', 'Redmine\Api\News'],
-            ['project', 'Redmine\Api\Project'],
-            ['query', 'Redmine\Api\Query'],
-            ['role', 'Redmine\Api\Role'],
-            ['time_entry', 'Redmine\Api\TimeEntry'],
-            ['time_entry_activity', 'Redmine\Api\TimeEntryActivity'],
-            ['tracker', 'Redmine\Api\Tracker'],
-            ['user', 'Redmine\Api\User'],
-            ['version', 'Redmine\Api\Version'],
-            ['wiki', 'Redmine\Api\Wiki'],
+            ['attachment', \Redmine\Api\Attachment::class],
+            ['group', \Redmine\Api\Group::class],
+            ['custom_fields', \Redmine\Api\CustomField::class],
+            ['issue', \Redmine\Api\Issue::class],
+            ['issue_category', \Redmine\Api\IssueCategory::class],
+            ['issue_priority', \Redmine\Api\IssuePriority::class],
+            ['issue_relation', \Redmine\Api\IssueRelation::class],
+            ['issue_status', \Redmine\Api\IssueStatus::class],
+            ['membership', \Redmine\Api\Membership::class],
+            ['news', \Redmine\Api\News::class],
+            ['project', \Redmine\Api\Project::class],
+            ['query', \Redmine\Api\Query::class],
+            ['role', \Redmine\Api\Role::class],
+            ['time_entry', \Redmine\Api\TimeEntry::class],
+            ['time_entry_activity', \Redmine\Api\TimeEntryActivity::class],
+            ['tracker', \Redmine\Api\Tracker::class],
+            ['user', \Redmine\Api\User::class],
+            ['version', \Redmine\Api\Version::class],
+            ['wiki', \Redmine\Api\Wiki::class],
         ];
     }
 
diff --git a/tests/Unit/Client/Psr18Client/RequestTest.php b/tests/Unit/Client/Psr18Client/RequestTest.php
index af0ab4f0..4062e1dd 100644
--- a/tests/Unit/Client/Psr18Client/RequestTest.php
+++ b/tests/Unit/Client/Psr18Client/RequestTest.php
@@ -25,7 +25,7 @@ class RequestTest extends TestCase
      * @dataProvider getRequestReponseData
      */
     #[DataProvider('getRequestReponseData')]
-    public function testRequestReturnsCorrectResponse($method, $data, $statusCode, $contentType, $content): void
+    public function testRequestReturnsCorrectResponse(string $method, string $data, int $statusCode, string $contentType, string $content): void
     {
         $httpClient = $this->createConfiguredMock(ClientInterface::class, [
             'sendRequest' => $this->createConfiguredMock(ResponseInterface::class, [
diff --git a/tests/Unit/Client/Psr18ClientTest.php b/tests/Unit/Client/Psr18ClientTest.php
index 472cf458..03332b9c 100644
--- a/tests/Unit/Client/Psr18ClientTest.php
+++ b/tests/Unit/Client/Psr18ClientTest.php
@@ -257,7 +257,7 @@ public function testRequestGetReturnsFalse(): void
      * @dataProvider getRequestReponseData
      */
     #[DataProvider('getRequestReponseData')]
-    public function testRequestsReturnsCorrectContent($method, $data, $boolReturn, $statusCode, $contentType, $content): void
+    public function testRequestsReturnsCorrectContent(string $method, string $data, bool $boolReturn, int $statusCode, string $contentType, string $content): void
     {
         $stream = $this->createMock(StreamInterface::class);
         $stream->method('__toString')->willReturn($content);
@@ -477,25 +477,25 @@ public function testGetApiShouldReturnApiInstance(string $apiName, string $class
     public static function getApiClassesProvider(): array
     {
         return [
-            ['attachment', 'Redmine\Api\Attachment'],
-            ['group', 'Redmine\Api\Group'],
-            ['custom_fields', 'Redmine\Api\CustomField'],
-            ['issue', 'Redmine\Api\Issue'],
-            ['issue_category', 'Redmine\Api\IssueCategory'],
-            ['issue_priority', 'Redmine\Api\IssuePriority'],
-            ['issue_relation', 'Redmine\Api\IssueRelation'],
-            ['issue_status', 'Redmine\Api\IssueStatus'],
-            ['membership', 'Redmine\Api\Membership'],
-            ['news', 'Redmine\Api\News'],
-            ['project', 'Redmine\Api\Project'],
-            ['query', 'Redmine\Api\Query'],
-            ['role', 'Redmine\Api\Role'],
-            ['time_entry', 'Redmine\Api\TimeEntry'],
-            ['time_entry_activity', 'Redmine\Api\TimeEntryActivity'],
-            ['tracker', 'Redmine\Api\Tracker'],
-            ['user', 'Redmine\Api\User'],
-            ['version', 'Redmine\Api\Version'],
-            ['wiki', 'Redmine\Api\Wiki'],
+            ['attachment', \Redmine\Api\Attachment::class],
+            ['group', \Redmine\Api\Group::class],
+            ['custom_fields', \Redmine\Api\CustomField::class],
+            ['issue', \Redmine\Api\Issue::class],
+            ['issue_category', \Redmine\Api\IssueCategory::class],
+            ['issue_priority', \Redmine\Api\IssuePriority::class],
+            ['issue_relation', \Redmine\Api\IssueRelation::class],
+            ['issue_status', \Redmine\Api\IssueStatus::class],
+            ['membership', \Redmine\Api\Membership::class],
+            ['news', \Redmine\Api\News::class],
+            ['project', \Redmine\Api\Project::class],
+            ['query', \Redmine\Api\Query::class],
+            ['role', \Redmine\Api\Role::class],
+            ['time_entry', \Redmine\Api\TimeEntry::class],
+            ['time_entry_activity', \Redmine\Api\TimeEntryActivity::class],
+            ['tracker', \Redmine\Api\Tracker::class],
+            ['user', \Redmine\Api\User::class],
+            ['version', \Redmine\Api\Version::class],
+            ['wiki', \Redmine\Api\Wiki::class],
         ];
     }
 
@@ -504,7 +504,7 @@ public function testCreateWithoutFactoryThrowsException(): void
         $this->expectException(Exception::class);
         $this->expectExceptionMessage('Redmine\Client\Psr18Client::__construct(): Argument #2 ($requestFactory) must be of type Psr\Http\Message\RequestFactoryInterface');
 
-        $client = new Psr18Client(
+        new Psr18Client(
             $this->createMock(ClientInterface::class),
             /** @phpstan-ignore-next-line We are providing an invalid parameter to test the exception */
             new stdClass(),
diff --git a/tests/Unit/Serializer/JsonSerializerTest.php b/tests/Unit/Serializer/JsonSerializerTest.php
index 81f7df7c..7eecbff4 100644
--- a/tests/Unit/Serializer/JsonSerializerTest.php
+++ b/tests/Unit/Serializer/JsonSerializerTest.php
@@ -93,7 +93,7 @@ public function testCreateFromStringWithInvalidStringThrowsException(string $mes
         $this->expectException(SerializerException::class);
         $this->expectExceptionMessage($message);
 
-        $serializer = JsonSerializer::createFromString($data);
+        JsonSerializer::createFromString($data);
     }
 
     public static function getNormalizedToEncodedData(): array
@@ -184,7 +184,7 @@ public static function getNormalizedToEncodedData(): array
      * @dataProvider getNormalizedToEncodedData
      */
     #[DataProvider('getNormalizedToEncodedData')]
-    public function testCreateFromArrayEncodesToExpectedString(array $data, $expected): void
+    public function testCreateFromArrayEncodesToExpectedString(array $data, string $expected): void
     {
         $serializer = JsonSerializer::createFromArray($data);
 
@@ -210,6 +210,6 @@ public function testCreateFromArrayWithInvalidDataThrowsException(string $messag
         $this->expectException(SerializerException::class);
         $this->expectExceptionMessage($message);
 
-        $serializer = JsonSerializer::createFromArray($data);
+        JsonSerializer::createFromArray($data);
     }
 }
diff --git a/tests/Unit/Serializer/XmlSerializerTest.php b/tests/Unit/Serializer/XmlSerializerTest.php
index cc077070..f4089d11 100644
--- a/tests/Unit/Serializer/XmlSerializerTest.php
+++ b/tests/Unit/Serializer/XmlSerializerTest.php
@@ -17,7 +17,7 @@ class XmlSerializerTest extends TestCase
      * @dataProvider getEncodedToNormalizedData
      */
     #[DataProvider('getEncodedToNormalizedData')]
-    public function testCreateFromStringDecodesToExpectedNormalizedData(string $data, $expected): void
+    public function testCreateFromStringDecodesToExpectedNormalizedData(string $data, array $expected): void
     {
         $serializer = XmlSerializer::createFromString($data);
 
@@ -115,7 +115,7 @@ public static function getInvalidEncodedData(): array
      * @dataProvider getNormalizedToEncodedData
      */
     #[DataProvider('getNormalizedToEncodedData')]
-    public function testCreateFromArrayEncodesToExpectedString(array $data, $expected): void
+    public function testCreateFromArrayEncodesToExpectedString(array $data, string $expected): void
     {
         $serializer = XmlSerializer::createFromArray($data);