diff --git a/.github/dependabot.yml b/.github/dependabot.yml
new file mode 100644
index 0000000..b01043c
--- /dev/null
+++ b/.github/dependabot.yml
@@ -0,0 +1,11 @@
+version: 2
+updates:
+    -
+        package-ecosystem: composer
+        directory: "/"
+        schedule:
+            interval: monthly
+        versioning-strategy: auto
+        groups:
+            dev-dependencies:
+                dependency-type: "development"
diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index f3b7f28..879203e 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -8,11 +8,11 @@ jobs:
 
     strategy:
       matrix:
-        php: [8.0, 8.1]
+        php: [8.1, 8.2, 8.3]
 
     steps:
     - name: Checkout code
-      uses: actions/checkout@v2
+      uses: actions/checkout@v4
 
     - name: Setup PHP
       uses: shivammathur/setup-php@v2
@@ -26,6 +26,12 @@ jobs:
     - name: Install dependencies
       run: composer install --prefer-dist --no-progress --no-interaction --no-suggest
 
+    - name: Execute Code Sniffer
+      run: vendor/bin/phpcs
+
+    - name: Execute PHP Stan
+      run: vendor/bin/phpstan
+
     - name: Run test suite
       run: |
         php -S 127.0.0.1:8000 -t tests/data/app >/dev/null 2>&1 &
diff --git a/composer.json b/composer.json
index a9c2509..ce86167 100644
--- a/composer.json
+++ b/composer.json
@@ -18,17 +18,19 @@
     ],
     "homepage": "https://codeception.com/",
     "require": {
-        "php": "^8.0",
+        "php": "^8.1",
         "ext-json": "*",
         "codeception/codeception": "*@dev",
         "codeception/lib-innerbrowser": "*@dev",
         "guzzlehttp/guzzle": "^7.4",
-        "symfony/browser-kit": "^5.4 || ^6.0 || ^7.0"
+        "symfony/browser-kit": "^5.4 | ^6.0 | ^7.0"
     },
     "require-dev": {
         "ext-curl": "*",
+        "squizlabs/php_codesniffer": "^3.10",
+        "phpstan/phpstan": "^1.10",
         "aws/aws-sdk-php": "^3.199",
-        "codeception/module-rest": "^2.0 || *@dev"
+        "codeception/module-rest": "^2.0 | *@dev"
     },
     "conflict": {
         "codeception/codeception": "<5.0",
@@ -37,7 +39,6 @@
     "suggest": {
         "codeception/phpbuiltinserver": "Start and stop PHP built-in web server for your tests"
     },
-    "minimum-stability": "dev",
     "autoload": {
         "classmap": [
             "src/"
diff --git a/phpcs.xml b/phpcs.xml
new file mode 100644
index 0000000..7b36367
--- /dev/null
+++ b/phpcs.xml
@@ -0,0 +1,23 @@
+<?xml version="1.0"?>
+<ruleset xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" name="PHP_CodeSniffer" xsi:noNamespaceSchemaLocation="phpcs.xsd">
+    <description>The coding standard.</description>
+
+    <config name="testVersion" value="8.1-"/>
+
+    <file>src</file>
+
+    <arg name="basepath" value="./"/>
+    <arg name="colors"/>
+    <arg name="parallel" value="5"/>
+    <arg value="np"/>
+
+    <rule ref="Internal.Tokenizer.Exception">
+        <type>error</type>
+    </rule>
+
+    <rule ref="PSR12"/>
+
+    <rule ref="PSR2.Methods.MethodDeclaration.Underscore">
+        <type>warning</type>
+    </rule>
+</ruleset>
\ No newline at end of file
diff --git a/phpstan.neon b/phpstan.neon
new file mode 100644
index 0000000..dec5108
--- /dev/null
+++ b/phpstan.neon
@@ -0,0 +1,4 @@
+parameters:
+    paths:
+        - ./src
+    level: 5
\ No newline at end of file
diff --git a/src/Codeception/Lib/Connector/Guzzle.php b/src/Codeception/Lib/Connector/Guzzle.php
index 3816b1d..55594bd 100644
--- a/src/Codeception/Lib/Connector/Guzzle.php
+++ b/src/Codeception/Lib/Connector/Guzzle.php
@@ -23,6 +23,9 @@
 
 class Guzzle extends AbstractBrowser
 {
+    /**
+     * @var array<string, mixed>
+     */
     protected array $requestOptions = [
         'allow_redirects' => false,
         'headers'         => [],
@@ -115,7 +118,7 @@ protected function createResponse(Psr7Response $psr7Response): BrowserKitRespons
             $contentType = 'text/html';
         }
 
-        if (strpos($contentType, 'charset=') === false) {
+        if (str_contains($contentType, 'charset=') === false) {
             if (preg_match('#<meta[^>]+charset *= *["\']?([a-zA-Z\-0-9]+)#i', $body, $matches)) {
                 $contentType .= ';charset=' . $matches[1];
             }
@@ -159,10 +162,10 @@ protected function createResponse(Psr7Response $psr7Response): BrowserKitRespons
     protected function getAbsoluteUri(string $uri): string
     {
         $baseUri = $this->client->getConfig('base_uri');
-        if (strpos($uri, '://') === false && strpos($uri, '//') !== 0) {
-            if (strpos($uri, '/') === 0) {
+        if (str_contains($uri, '://') === false && !str_starts_with($uri, '//')) {
+            if (str_starts_with($uri, '/')) {
                 $baseUriPath = $baseUri->getPath();
-                if (!empty($baseUriPath) && strpos($uri, (string) $baseUriPath) === 0) {
+                if (!empty($baseUriPath) && str_starts_with($uri, (string) $baseUriPath)) {
                     $uri = substr($uri, strlen($baseUriPath));
                 }
 
@@ -178,9 +181,9 @@ protected function getAbsoluteUri(string $uri): string
         return Uri::mergeUrls((string)$baseUri, $uri);
     }
 
-    protected function doRequest($request)
+    protected function doRequest(object $request)
     {
-        /** @var $request BrowserKitRequest **/
+        /** @var BrowserKitRequest $request **/
         $guzzleRequest = new Psr7Request(
             $request->getMethod(),
             $request->getUri(),
@@ -190,17 +193,17 @@ protected function doRequest($request)
         $options = $this->requestOptions;
         $options['cookies'] = $this->extractCookies($guzzleRequest->getUri()->getHost());
         $multipartData = $this->extractMultipartFormData($request);
-        if (!empty($multipartData)) {
+        if ($multipartData !== []) {
             $options['multipart'] = $multipartData;
         }
 
         $formData = $this->extractFormData($request);
-        if (empty($multipartData) && $formData) {
+        if ($multipartData === [] && $formData) {
             $options['form_params'] = $formData;
         }
 
         try {
-            if (null !== $this->awsCredentials) {
+            if ($this->awsCredentials instanceof AwsCredentials) {
                 $response = $this->client->send($this->awsSignature->signRequest($guzzleRequest, $this->awsCredentials), $options);
             } else {
                 $response = $this->client->send($guzzleRequest, $options);
@@ -213,6 +216,7 @@ protected function doRequest($request)
             $response = $exception->getResponse();
         }
 
+        // @phpstan-ignore-next-line
         return $this->createResponse($response);
     }
 
@@ -227,7 +231,7 @@ protected function extractHeaders(BrowserKitRequest $request): array
         $contentHeaders = ['Content-Length' => true, 'Content-Md5' => true, 'Content-Type' => true];
         foreach ($server as $header => $val) {
             $header = html_entity_decode(implode('-', array_map('ucfirst', explode('-', strtolower(str_replace('_', '-', $header))))), ENT_NOQUOTES);
-            if (strpos($header, 'Http-') === 0) {
+            if (str_starts_with($header, 'Http-')) {
                 $headers[substr($header, 5)] = $val;
             } elseif (isset($contentHeaders[$header])) {
                 $headers[$header] = $val;
@@ -237,6 +241,9 @@ protected function extractHeaders(BrowserKitRequest $request): array
         return $headers;
     }
 
+    /**
+     * @return array<int, mixed>|null
+     */
     protected function extractFormData(BrowserKitRequest $browserKitRequest): ?array
     {
         if (!in_array(strtoupper($browserKitRequest->getMethod()), ['POST', 'PUT', 'PATCH', 'DELETE'])) {
@@ -257,14 +264,17 @@ protected function extractFormData(BrowserKitRequest $browserKitRequest): ?array
         return $browserKitRequest->getParameters();
     }
 
-    protected function extractMultipartFormData(BrowserKitRequest $browserKitRequest)
+    /**
+     * @return array<string, mixed>
+     */
+    protected function extractMultipartFormData(BrowserKitRequest $browserKitRequest): array
     {
         if (!in_array(strtoupper($browserKitRequest->getMethod()), ['POST', 'PUT', 'PATCH'])) {
             return [];
         }
 
         $parts = $this->mapFiles($browserKitRequest->getFiles());
-        if (empty($parts)) {
+        if ($parts === []) {
             return [];
         }
 
@@ -275,11 +285,14 @@ protected function extractMultipartFormData(BrowserKitRequest $browserKitRequest
         return $parts;
     }
 
-    protected function formatMultipart($parts, $key, $value)
+    /**
+     * @return array<string, mixed>
+     */
+    protected function formatMultipart(mixed $parts, string $key, mixed $value): array
     {
         if (is_array($value)) {
             foreach ($value as $subKey => $subValue) {
-                $parts = array_merge($this->formatMultipart([], $key.sprintf('[%s]', $subKey), $subValue), $parts);
+                $parts = array_merge($this->formatMultipart([], $key . sprintf('[%s]', $subKey), $subValue), $parts);
             }
 
             return $parts;
@@ -289,7 +302,11 @@ protected function formatMultipart($parts, $key, $value)
         return $parts;
     }
 
-    protected function mapFiles($requestFiles, $arrayName = ''): array
+    /**
+     * @param array<int, mixed> $requestFiles
+     * @return array<int, mixed>
+     */
+    protected function mapFiles(array $requestFiles, ?string $arrayName = ''): array
     {
         $files = [];
         foreach ($requestFiles as $name => $info) {
@@ -329,7 +346,7 @@ protected function mapFiles($requestFiles, $arrayName = ''): array
         return $files;
     }
 
-    protected function extractCookies($host): GuzzleCookieJar
+    protected function extractCookies(string $host): GuzzleCookieJar
     {
         $jar = [];
         $cookies = $this->getCookieJar()->all();
@@ -345,7 +362,7 @@ protected function extractCookies($host): GuzzleCookieJar
         return new GuzzleCookieJar(false, $jar);
     }
 
-    public static function createHandler($handler): GuzzleHandlerStack
+    public static function createHandler(mixed $handler): GuzzleHandlerStack
     {
         if ($handler instanceof GuzzleHandlerStack) {
             return $handler;
@@ -360,7 +377,7 @@ public static function createHandler($handler): GuzzleHandlerStack
         }
 
         if (is_string($handler) && class_exists($handler)) {
-            return GuzzleHandlerStack::create(new $handler);
+            return GuzzleHandlerStack::create(new $handler());
         }
 
         if (is_callable($handler)) {
@@ -370,7 +387,10 @@ public static function createHandler($handler): GuzzleHandlerStack
         return GuzzleHandlerStack::create();
     }
 
-    public function setAwsAuth($config): void
+    /**
+     * @param array<string, mixed> $config
+     */
+    public function setAwsAuth(array $config): void
     {
         $this->awsCredentials = new AwsCredentials($config['key'], $config['secret']);
         $this->awsSignature = new AwsSignatureV4($config['service'], $config['region']);
diff --git a/src/Codeception/Module/PhpBrowser.php b/src/Codeception/Module/PhpBrowser.php
index 6b6f90e..5049f5c 100644
--- a/src/Codeception/Module/PhpBrowser.php
+++ b/src/Codeception/Module/PhpBrowser.php
@@ -135,7 +135,7 @@ public function _initialize()
 
     public function _before(TestInterface $test)
     {
-        if (!$this->client) {
+        if (!$this->client instanceof AbstractBrowser) {
             $this->client = new Guzzle();
         }
 
@@ -155,12 +155,14 @@ public function setHeader(string $name, string $value): void
         $this->haveHttpHeader($name, $value);
     }
 
-    public function amHttpAuthenticated($username, $password): void
+    public function amHttpAuthenticated(string $username, string $password): void
     {
-        $this->client->setAuth($username, $password);
+        if ($this->client instanceof Guzzle) {
+            $this->client->setAuth($username, $password);
+        }
     }
 
-    public function amOnUrl($url): void
+    public function amOnUrl(string $url): void
     {
         $host = Uri::retrieveHost($url);
         $config = $this->config;
@@ -175,7 +177,7 @@ public function amOnUrl($url): void
         $this->amOnPage($page);
     }
 
-    public function amOnSubdomain($subdomain): void
+    public function amOnSubdomain(string $subdomain): void
     {
         $url = $this->config['url'];
         $url = preg_replace('#(https?://)(.*\.)(.*\.)#', "$1$3", $url); // removing current subdomain
@@ -206,18 +208,13 @@ protected function onReconfigure()
      *
      * It is not recommended to use this command on a regular basis.
      * If Codeception lacks important Guzzle Client methods, implement them and submit patches.
-     *
-     * @return mixed
      */
-    public function executeInGuzzle(Closure $function)
+    public function executeInGuzzle(Closure $function): mixed
     {
         return $function($this->guzzle);
     }
 
-    /**
-     * @return int|string
-     */
-    public function _getResponseCode()
+    public function _getResponseCode(): int|string
     {
         return $this->getResponseStatusCode();
     }
@@ -245,21 +242,24 @@ public function _prepareSession(): void
 
         $defaults['base_uri'] = $this->config['url'];
         $defaults['curl'] = $curlOptions;
-        $handler = Guzzle::createHandler($this->config['handler']);
-        if ($handler && is_array($this->config['middleware'])) {
+        $handlerStack = Guzzle::createHandler($this->config['handler']);
+        if (is_array($this->config['middleware'])) {
             foreach ($this->config['middleware'] as $middleware) {
-                $handler->push($middleware);
+                $handlerStack->push($middleware);
             }
         }
 
-        $defaults['handler'] = $handler;
+        $defaults['handler'] = $handlerStack;
         $this->guzzle = new GuzzleClient($defaults);
 
         $this->client->setRefreshMaxInterval($this->config['refresh_max_interval']);
         $this->client->setClient($this->guzzle);
     }
 
-    public function _backupSession(): array
+    /**
+     * @return array<string, mixed>
+     */
+    public function _backupSession()
     {
         return [
             'client' => $this->client,
@@ -269,6 +269,9 @@ public function _backupSession(): array
         ];
     }
 
+    /**
+     * @param array<string, mixed> $session
+     */
     public function _loadSession($session): void
     {
         foreach ($session as $key => $val) {
@@ -276,6 +279,9 @@ public function _loadSession($session): void
         }
     }
 
+    /**
+     * @param ?array<string, mixed> $session
+     */
     public function _closeSession($session = null): void
     {
         unset($session);
diff --git a/tests/_support/UnitTester.php b/tests/_support/UnitTester.php
index e19544a..6aeac82 100644
--- a/tests/_support/UnitTester.php
+++ b/tests/_support/UnitTester.php
@@ -1,6 +1,5 @@
 <?php
 
-
 /**
  * Inherited Methods
  * @method void wantToTest($text)
diff --git a/tests/data/app/controllers.php b/tests/data/app/controllers.php
index 793e707..f330673 100755
--- a/tests/data/app/controllers.php
+++ b/tests/data/app/controllers.php
@@ -1,203 +1,253 @@
 <?php
-class index {
-    function GET($matches) {
-        include __DIR__.'/view/index.php';
+
+class index
+{
+    function GET($matches)
+    {
+        include __DIR__ . '/view/index.php';
     }
 
-    function POST($matches) {
-        include __DIR__.'/view/index.php';
+    function POST($matches)
+    {
+        include __DIR__ . '/view/index.php';
     }
 }
 
-class info {
-    function GET() {
-        if (isset($_SERVER['HTTP_X_REQUESTED_WITH'])) data::set('ajax',array('GET'));
+class info
+{
+    function GET()
+    {
+        if (isset($_SERVER['HTTP_X_REQUESTED_WITH'])) {
+            data::set('ajax', array('GET'));
+        }
         data::set('params', $_GET);
-        include __DIR__.'/view/info.php';
+        include __DIR__ . '/view/info.php';
     }
-
 }
 
-class redirect {
-    function GET() {
+class redirect
+{
+    function GET()
+    {
         header('Location: /info');
     }
 }
 
-class redirect4 {
-    function GET() {
+class redirect4
+{
+    function GET()
+    {
         header('Location: /search?ln=test@gmail.com&sn=testnumber');
     }
 }
 
-class redirect_relative {
-    function GET() {
+class redirect_relative
+{
+    function GET()
+    {
         header('Location: info');
     }
 }
 
-class redirect2 {
-    function GET() {
-        include __DIR__.'/view/redirect2.php';
+class redirect2
+{
+    function GET()
+    {
+        include __DIR__ . '/view/redirect2.php';
     }
 }
 
-class redirect3 {
-    function GET() {
+class redirect3
+{
+    function GET()
+    {
         header('Refresh:0;url=/info');
     }
 }
 
-class redirect_twice {
-    function GET() {
+class redirect_twice
+{
+    function GET()
+    {
         header('Location: /redirect3');
     }
 }
 
-class redirect_params {
-    function GET() {
-        include __DIR__.'/view/redirect_params.php';
+class redirect_params
+{
+    function GET()
+    {
+        include __DIR__ . '/view/redirect_params.php';
     }
 }
 
-class redirect_interval {
-    function GET() {
-        include __DIR__.'/view/redirect_interval.php';
+class redirect_interval
+{
+    function GET()
+    {
+        include __DIR__ . '/view/redirect_interval.php';
     }
 }
 
-class redirect_meta_refresh {
-    function GET() {
-        include __DIR__.'/view/redirect_meta_refresh.php';
+class redirect_meta_refresh
+{
+    function GET()
+    {
+        include __DIR__ . '/view/redirect_meta_refresh.php';
     }
 }
 
-class redirect_header_interval {
-    function GET() {
-        include __DIR__.'/view/index.php';
+class redirect_header_interval
+{
+    function GET()
+    {
+        include __DIR__ . '/view/index.php';
         header('Refresh:1800;url=/info');
     }
 }
 
-class redirect_base_uri_has_path {
-    function GET() {
+class redirect_base_uri_has_path
+{
+    function GET()
+    {
         header('Refresh:0;url=/somepath/info');
     }
 }
 
-class redirect_base_uri_has_path_302 {
-    function GET() {
+class redirect_base_uri_has_path_302
+{
+    function GET()
+    {
         header('Location: /somepath/info', true, 302);
     }
 }
 
-class location_201 {
-    function GET() {
+class location_201
+{
+    function GET()
+    {
         header('Location: /info', true, 201);
     }
 }
 
-class external_url {
-    function GET() {
+class external_url
+{
+    function GET()
+    {
         include __DIR__ . '/view/external_url.php';
     }
 }
 
 
-class login {
-
-    function GET($matches) {
-        include __DIR__.'/view/login.php';
+class login
+{
+    function GET($matches)
+    {
+        include __DIR__ . '/view/login.php';
     }
 
-    function POST() {
+    function POST()
+    {
         data::set('form', $_POST);
-        include __DIR__.'/view/login.php';
+        include __DIR__ . '/view/login.php';
     }
-
 }
 
-class cookies {
-
-    function GET($matches) {
+class cookies
+{
+    function GET($matches)
+    {
         if (isset($_COOKIE['foo']) && $_COOKIE['foo'] === 'bar1') {
             if (isset($_COOKIE['baz']) && $_COOKIE['baz'] === 'bar2') {
                 header('Location: /info');
             }
         } else {
-            include __DIR__.'/view/cookies.php';
+            include __DIR__ . '/view/cookies.php';
         }
     }
 
-    function POST() {
+    function POST()
+    {
         setcookie('f', 'b', time() + 60, null, null, false, true);
         setcookie('foo', 'bar1', time() + 60, null, 'sub.localhost', false, true);
-        setcookie('baz', 'bar2', time() + 60,  null, 'sub.localhost', false, true);
+        setcookie('baz', 'bar2', time() + 60, null, 'sub.localhost', false, true);
         data::set('form', $_POST);
-        include __DIR__.'/view/cookies.php';
+        include __DIR__ . '/view/cookies.php';
     }
 }
 
-class cookiesHeader {
+class cookiesHeader
+{
     public function GET()
     {
         header("Set-Cookie: a=b;Path=/;");
         header("Set-Cookie: c=d;Path=/;", false);
-        include __DIR__.'/view/index.php';
+        include __DIR__ . '/view/index.php';
     }
 }
 
-class iframe {
+class iframe
+{
     public function GET()
     {
-        include __DIR__.'/view/iframe.php';
+        include __DIR__ . '/view/iframe.php';
     }
 }
 
-class form {
-    function GET($matches) {
+class form
+{
+    function GET($matches)
+    {
         data::set('query', $_GET);
         $url = strtolower($matches[1]);
         if (empty($matches[1])) {
             $url = 'index';
         }
-        include __DIR__.'/view/form/'.$url.'.php';
+        include __DIR__ . '/view/form/' . $url . '.php';
     }
 
-    function POST() {
+    function POST()
+    {
         data::set('query', $_GET);
         data::set('form', $_POST);
         data::set('files', $_FILES);
         if (isset($_SERVER['HTTP_X_REQUESTED_WITH'])) {
-            data::set('ajax','post');
+            data::set('ajax', 'post');
         }
 
         $notice = 'Thank you!';
-        include __DIR__.'/view/index.php';
+        include __DIR__ . '/view/index.php';
     }
 }
 
-class articles {
-    function DELETE() {
+class articles
+{
+    function DELETE()
+    {
     }
 
-    function PUT() {
+    function PUT()
+    {
     }
 }
 
-class search {
-    function GET($matches) {
+class search
+{
+    function GET($matches)
+    {
         $result = null;
         if (isset($_GET['searchQuery']) && $_GET['searchQuery'] == 'test') {
             $result = 'Success';
         }
         data::set('params', $_GET);
-        include __DIR__.'/view/search.php';
+        include __DIR__ . '/view/search.php';
     }
 }
 
-class httpAuth {
-    function GET() {
+class httpAuth
+{
+    function GET()
+    {
         if (!isset($_SERVER['PHP_AUTH_USER'])) {
             header('WWW-Authenticate: Basic realm="test"');
             header('HTTP/1.0 401 Unauthorized');
@@ -212,55 +262,72 @@ function GET() {
     }
 }
 
-class register {
-    function GET() {
-        include __DIR__.'/view/register.php';
+class register
+{
+    function GET()
+    {
+        include __DIR__ . '/view/register.php';
     }
 
-    function POST() {
+    function POST()
+    {
         $this->GET();
     }
 }
 
-class contentType1 {
-    function GET() {
+class contentType1
+{
+    function GET()
+    {
         header('Content-Type:', true);
-        include __DIR__.'/view/content_type.php';
+        include __DIR__ . '/view/content_type.php';
     }
 }
 
-class contentType2 {
-    function GET() {
+class contentType2
+{
+    function GET()
+    {
         header('Content-Type:', true);
-        include __DIR__.'/view/content_type2.php';
+        include __DIR__ . '/view/content_type2.php';
     }
 }
 
-class unsetCookie {
-    function GET() {
+class unsetCookie
+{
+    function GET()
+    {
         header('Set-Cookie: a=; Expires=Thu, 01 Jan 1970 00:00:01 GMT');
     }
 }
 
-class basehref {
-    function GET() {
-        include __DIR__.'/view/basehref.php';
+class basehref
+{
+    function GET()
+    {
+        include __DIR__ . '/view/basehref.php';
     }
 }
 
-class jserroronload {
-    function GET() {
-        include __DIR__.'/view/jserroronload.php';
+class jserroronload
+{
+    function GET()
+    {
+        include __DIR__ . '/view/jserroronload.php';
     }
 }
 
-class userAgent {
-    function GET() {
+class userAgent
+{
+    function GET()
+    {
         echo $_SERVER['HTTP_USER_AGENT'];
     }
 }
-class minimal {
-    function GET() {
-        include __DIR__.'/view/minimal.php';
+class minimal
+{
+    function GET()
+    {
+        include __DIR__ . '/view/minimal.php';
     }
 }
diff --git a/tests/data/app/data.php b/tests/data/app/data.php
index c1877c2..d7dca0e 100755
--- a/tests/data/app/data.php
+++ b/tests/data/app/data.php
@@ -1,9 +1,11 @@
 <?php
-class data {
 
+class data
+{
     public static $filename = '/db';
 
-    public static function get($key) {
+    public static function get($key)
+    {
         $data = self::load();
         return $data[$key];
     }
@@ -29,14 +31,16 @@ public static function clean()
 
     protected static function load()
     {
-        $data = file_get_contents(__DIR__.self::$filename);
+        $data = file_get_contents(__DIR__ . self::$filename);
         $data = $data ? unserialize($data) : $data = array();
-        if (!is_array($data)) $data = array();
+        if (!is_array($data)) {
+            $data = array();
+        }
         return $data;
     }
 
     protected static function save($data)
     {
-        file_put_contents(__DIR__.self::$filename, serialize($data));
+        file_put_contents(__DIR__ . self::$filename, serialize($data));
     }
-}
\ No newline at end of file
+}
diff --git a/tests/data/app/glue.php b/tests/data/app/glue.php
index 94c95b8..a2e65f1 100755
--- a/tests/data/app/glue.php
+++ b/tests/data/app/glue.php
@@ -10,7 +10,7 @@
      *      * delimiter (/) are automatically escaped: (\/)
      *      * The beginning and end are anchored (^ $)
      *      * An optional end slash is added (/?)
-     *	    * The i option is added for case-insensitive searches
+     *      * The i option is added for case-insensitive searches
      *
      * Example:
      *
@@ -28,48 +28,49 @@
      * glue::stick($urls);
      *
      */
-    class glue {
-
-        /**
-         * stick
-         *
-         * the main static function of the glue class.
-         *
-         * @param   array    	$urls  	    The regex-based url to class mapping
-         * @throws  Exception               Thrown if corresponding class is not found
-         * @throws  Exception               Thrown if no match is found
-         * @throws  BadMethodCallException  Thrown if a corresponding GET,POST is not found
-         *
-         */
-        static function stick ($urls) {
+class glue
+{
+    /**
+     * stick
+     *
+     * the main static function of the glue class.
+     *
+     * @param   array       $urls       The regex-based url to class mapping
+     * @throws  Exception               Thrown if corresponding class is not found
+     * @throws  Exception               Thrown if no match is found
+     * @throws  BadMethodCallException  Thrown if a corresponding GET,POST is not found
+     *
+     */
+    static function stick($urls)
+    {
 
-            $method = strtoupper($_SERVER['REQUEST_METHOD']);
-            $path = $_SERVER['REQUEST_URI'];
+        $method = strtoupper($_SERVER['REQUEST_METHOD']);
+        $path = $_SERVER['REQUEST_URI'];
 
-            $found = false;
+        $found = false;
 
-            krsort($urls);
+        krsort($urls);
 
-            foreach ($urls as $regex => $class) {
-                $regex = str_replace('/', '\/', $regex);
-                $regex = '^' . $regex . '\/?$';
-                if (preg_match("/$regex/i", $path, $matches)) {
-                    $found = true;
-                    if (class_exists($class)) {
-                        $obj = new $class;
-                        if (method_exists($obj, $method)) {
-                            $obj->$method($matches);
-                        } else {
-                            throw new BadMethodCallException("Method, $method, not supported.");
-                        }
+        foreach ($urls as $regex => $class) {
+            $regex = str_replace('/', '\/', $regex);
+            $regex = '^' . $regex . '\/?$';
+            if (preg_match("/$regex/i", $path, $matches)) {
+                $found = true;
+                if (class_exists($class)) {
+                    $obj = new $class();
+                    if (method_exists($obj, $method)) {
+                        $obj->$method($matches);
                     } else {
-                        throw new Exception("Class, $class, not found.");
+                        throw new BadMethodCallException("Method, $method, not supported.");
                     }
-                    break;
+                } else {
+                    throw new Exception("Class, $class, not found.");
                 }
+                break;
             }
-            if (!$found) {
-                throw new Exception("URL, $path, not found.");
-            }
+        }
+        if (!$found) {
+            throw new Exception("URL, $path, not found.");
         }
     }
+}
diff --git a/tests/data/app/index.php b/tests/data/app/index.php
index 4c65804..243d816 100644
--- a/tests/data/app/index.php
+++ b/tests/data/app/index.php
@@ -1,10 +1,12 @@
 <?php
-if (!headers_sent()) header('Content-Type: text/html; charset=UTF-8');
+
+if (!headers_sent()) {
+    header('Content-Type: text/html; charset=UTF-8');
+}
 
 require_once('glue.php');
 require_once('data.php');
 require_once('controllers.php');
-
 $urls = array(
     '/' => 'index',
     '/info' => 'info',
@@ -42,5 +44,4 @@
     '/jserroronload' => 'jserroronload',
     '/minimal' => 'minimal',
 );
-
 glue::stick($urls);
diff --git a/tests/data/app/view/form/bug3824.php b/tests/data/app/view/form/bug3824.php
index 221fb98..64a02ff 100644
--- a/tests/data/app/view/form/bug3824.php
+++ b/tests/data/app/view/form/bug3824.php
@@ -7,9 +7,9 @@
 </form>
 
 <?php
-    if (isset($_POST['test']) && $_POST['test'] !== '_none') {
-        echo 'ERROR';
-    }
+if (isset($_POST['test']) && $_POST['test'] !== '_none') {
+    echo 'ERROR';
+}
 ?>
 
 </body></html>
diff --git a/tests/data/app/view/form/complex.php b/tests/data/app/view/form/complex.php
index 272bd84..dd35b91 100755
--- a/tests/data/app/view/form/complex.php
+++ b/tests/data/app/view/form/complex.php
@@ -41,4 +41,4 @@
     <?php print_r($_SERVER); ?>
 </form>
 </body>
-</html>
\ No newline at end of file
+</html>
diff --git a/tests/data/app/view/form/unchecked.php b/tests/data/app/view/form/unchecked.php
index 2e8848e..30fcbdf 100644
--- a/tests/data/app/view/form/unchecked.php
+++ b/tests/data/app/view/form/unchecked.php
@@ -8,10 +8,10 @@
 
 <div id="notice">
     <?php
-        if (isset($_GET['data'])) {
-            echo $_GET['data'] ? 1 : 0;
-        }
+    if (isset($_GET['data'])) {
+        echo $_GET['data'] ? 1 : 0;
+    }
     ?>
 </div>
 </body>
-</html>
\ No newline at end of file
+</html>
diff --git a/tests/data/app/view/index.php b/tests/data/app/view/index.php
index 3890759..5157fab 100755
--- a/tests/data/app/view/index.php
+++ b/tests/data/app/view/index.php
@@ -4,7 +4,9 @@
 
 <h1>Welcome to test app!</h1>
 
-<div class="notice"><?php if (isset($notice)) echo $notice; ?></div>
+<div class="notice"><?php if (isset($notice)) {
+    echo $notice;
+                    } ?></div>
 
 <p>
     <a href="/info" id="link">More info</a>
diff --git a/tests/data/app/view/info.php b/tests/data/app/view/info.php
index b8041ef..65c2ea9 100755
--- a/tests/data/app/view/info.php
+++ b/tests/data/app/view/info.php
@@ -12,7 +12,9 @@
     <a href="/" id="back"><img src="blank.gif" alt="Back"/></a>
 </p>
 
-<div class="notice"><?php if (isset($notice)) echo $notice; ?></div>
+<div class="notice"><?php if (isset($notice)) {
+    echo $notice;
+                    } ?></div>
 
 <h3>Don't do that at home!</h3>
 
diff --git a/tests/data/app/view/search.php b/tests/data/app/view/search.php
index 8c4de1d..ba457a8 100644
--- a/tests/data/app/view/search.php
+++ b/tests/data/app/view/search.php
@@ -5,7 +5,9 @@
 <body>
     <div id="searchInputHeader">
         
-        <?php if (isset($result)): echo $result; endif; ?>
+        <?php if (isset($result)) :
+            echo $result;
+        endif; ?>
         <form action="/search" method="get" target="_self" name="searchInputHeaderForm">
             <input 
                 type="text"
@@ -15,4 +17,4 @@
         <div id="searchInputHeaderSubmit" onclick="searchInputHeaderForm.submit()"></div>
     </div>
 </body>
-</html>
\ No newline at end of file
+</html>
diff --git a/tests/data/rest/index.php b/tests/data/rest/index.php
index c04ebaa..c5d77ac 100755
--- a/tests/data/rest/index.php
+++ b/tests/data/rest/index.php
@@ -5,7 +5,7 @@
 $GLOBALS['RESTmap'] = [];
 
 $GLOBALS['RESTmap']['GET'] = [
-    'user' => function() {
+    'user' => function () {
         return [
             'name'    => 'davert',
             'email'   => 'davert@mail.ua',
@@ -18,7 +18,7 @@
                 'country' => 'Ukraine',
             ]];
     },
-    'zeroes' => function() {
+    'zeroes' => function () {
         return [
             'responseCode' => 0,
             'message' => 'OK',
@@ -29,7 +29,7 @@
             ],
         ];
     },
-    'foo' => function() {
+    'foo' => function () {
         if (isset($_SERVER['HTTP_FOO'])) {
             return 'foo: "' . $_SERVER['HTTP_FOO'] . '"';
         }
@@ -39,11 +39,11 @@
 ];
 
 $GLOBALS['RESTmap']['POST'] = [
-    'user' => function() {
+    'user' => function () {
         $name = $_POST['name'];
         return ['name' => $name];
     },
-    'file-upload' => function() {
+    'file-upload' => function () {
         return [
             'uploaded' => isset($_FILES['file']['tmp_name']) && file_exists($_FILES['file']['tmp_name']),
         ];
@@ -51,7 +51,7 @@
 ];
 
 $GLOBALS['RESTmap']['PUT'] = [
-    'user' => function() {
+    'user' => function () {
         $name = $_REQUEST['name'];
         $user = ['name' => 'davert', 'email' => 'davert@mail.ua'];
         $user['name'] = $name;
@@ -60,7 +60,7 @@
 ];
 
 $GLOBALS['RESTmap']['DELETE'] = [
-    'user' => function() {
+    'user' => function () {
         header('error', false, 404);
     }
 ];
diff --git a/tests/data/rest/server.php b/tests/data/rest/server.php
index 70e241c..ba051a4 100755
--- a/tests/data/rest/server.php
+++ b/tests/data/rest/server.php
@@ -1,8 +1,9 @@
 <?php
+
 function RESTServer()
 {
     // find the function/method to call
-    $callback = NULL;
+    $callback = null;
     if (preg_match('/rest\/([^\/]+)/i', $_SERVER['REQUEST_URI'], $m)) {
         if (isset($GLOBALS['RESTmap'][$_SERVER['REQUEST_METHOD']][$m[1]])) {
             $callback = $GLOBALS['RESTmap'][$_SERVER['REQUEST_METHOD']][$m[1]];
@@ -11,9 +12,8 @@ function RESTServer()
 
 
     if ($callback) {
-
-        // get the request data
-        $data = NULL;
+// get the request data
+        $data = null;
         if ($_SERVER['REQUEST_METHOD'] == 'GET') {
             $data = $_GET;
         } else if ($tmp = file_get_contents('php://input')) {
diff --git a/tests/unit/Codeception/Module/PhpBrowserRestTest.php b/tests/unit/Codeception/Module/PhpBrowserRestTest.php
index e618375..b0e70c2 100644
--- a/tests/unit/Codeception/Module/PhpBrowserRestTest.php
+++ b/tests/unit/Codeception/Module/PhpBrowserRestTest.php
@@ -14,11 +14,11 @@
 
 final class PhpBrowserRestTest extends Unit
 {
-    protected REST $module;
+    private REST $rest;
 
-    protected ?PhpBrowser $phpBrowser = null;
+    private ?PhpBrowser $phpBrowser = null;
 
-    protected function _setUp()
+    protected function _setUp(): void
     {
         $container = Stub::make(ModuleContainer::class);
         $this->phpBrowser = new PhpBrowser($container);
@@ -26,140 +26,140 @@ protected function _setUp()
         $this->phpBrowser->_setConfig(['url' => $url]);
         $this->phpBrowser->_initialize();
 
-        $this->module = Stub::make(REST::class);
-        $this->module->_inject($this->phpBrowser);
-        $this->module->_initialize();
-        $this->module->_before(Stub::makeEmpty(Cest::class));
-        
+        $this->rest = Stub::make(REST::class);
+        $this->rest->_inject($this->phpBrowser);
+        $this->rest->_initialize();
+        $this->rest->_before(Stub::makeEmpty(Cest::class));
+
         $this->phpBrowser->_before(Stub::makeEmpty(Cest::class));
     }
 
-    private function setStubResponse($response)
+    private function setStubResponse($response): void
     {
         $this->phpBrowser = Stub::make(PhpBrowser::class, ['_getResponseContent' => $response]);
-        $this->module->_inject($this->phpBrowser);
-        $this->module->_initialize();
-        $this->module->_before(Stub::makeEmpty(Cest::class));
+        $this->rest->_inject($this->phpBrowser);
+        $this->rest->_initialize();
+        $this->rest->_before(Stub::makeEmpty(Cest::class));
     }
 
-    public function testGet()
+    public function testGet(): void
     {
-        $this->module->sendGET('/rest/user/');
-        $this->module->seeResponseIsJson();
-        $this->module->seeResponseContains('davert');
-        $this->module->seeResponseContainsJson(['name' => 'davert']);
-        $this->module->seeResponseCodeIs(200);
-        $this->module->dontSeeResponseCodeIs(404);
+        $this->rest->sendGET('/rest/user/');
+        $this->rest->seeResponseIsJson();
+        $this->rest->seeResponseContains('davert');
+        $this->rest->seeResponseContainsJson(['name' => 'davert']);
+        $this->rest->seeResponseCodeIs(200);
+        $this->rest->dontSeeResponseCodeIs(404);
     }
 
-    public function testSendAbsoluteUrlGet()
+    public function testSendAbsoluteUrlGet(): void
     {
-        $this->module->sendGET('http://127.0.0.1:8010/rest/user/');
-        $this->module->seeResponseCodeIs(200);
+        $this->rest->sendGET('http://127.0.0.1:8010/rest/user/');
+        $this->rest->seeResponseCodeIs(200);
     }
 
-    public function testPost()
+    public function testPost(): void
     {
-        $this->module->sendPOST('/rest/user/', ['name' => 'john']);
-        $this->module->seeResponseContains('john');
-        $this->module->seeResponseContainsJson(['name' => 'john']);
+        $this->rest->sendPOST('/rest/user/', ['name' => 'john']);
+        $this->rest->seeResponseContains('john');
+        $this->rest->seeResponseContainsJson(['name' => 'john']);
     }
 
-    public function testValidJson()
+    public function testValidJson(): void
     {
         $this->setStubResponse('{"xxx": "yyy"}');
-        $this->module->seeResponseIsJson();
+        $this->rest->seeResponseIsJson();
         $this->setStubResponse('{"xxx": "yyy", "zzz": ["a","b"]}');
-        $this->module->seeResponseIsJson();
-        $this->module->seeResponseEquals('{"xxx": "yyy", "zzz": ["a","b"]}');
+        $this->rest->seeResponseIsJson();
+        $this->rest->seeResponseEquals('{"xxx": "yyy", "zzz": ["a","b"]}');
     }
 
-    public function testInvalidJson()
+    public function testInvalidJson(): void
     {
         $this->expectException(ExpectationFailedException::class);
         $this->setStubResponse('{xxx = yyy}');
-        $this->module->seeResponseIsJson();
+        $this->rest->seeResponseIsJson();
     }
 
-    public function testValidXml()
+    public function testValidXml(): void
     {
         $this->setStubResponse('<xml></xml>');
-        $this->module->seeResponseIsXml();
+        $this->rest->seeResponseIsXml();
         $this->setStubResponse('<xml><name>John</name></xml>');
-        $this->module->seeResponseIsXml();
-        $this->module->seeResponseEquals('<xml><name>John</name></xml>');
+        $this->rest->seeResponseIsXml();
+        $this->rest->seeResponseEquals('<xml><name>John</name></xml>');
     }
 
-    public function testInvalidXml()
+    public function testInvalidXml(): void
     {
         $this->expectException(ExpectationFailedException::class);
         $this->setStubResponse('<xml><name>John</surname></xml>');
-        $this->module->seeResponseIsXml();
+        $this->rest->seeResponseIsXml();
     }
 
-    public function testSeeInJson()
+    public function testSeeInJson(): void
     {
         $this->setStubResponse(
             '{"ticket": {"title": "Bug should be fixed", "user": {"name": "Davert"}, "labels": null}}'
         );
-        $this->module->seeResponseIsJson();
-        $this->module->seeResponseContainsJson(['name' => 'Davert']);
-        $this->module->seeResponseContainsJson(['user' => ['name' => 'Davert']]);
-        $this->module->seeResponseContainsJson(['ticket' => ['title' => 'Bug should be fixed']]);
-        $this->module->seeResponseContainsJson(['ticket' => ['user' => ['name' => 'Davert']]]);
-        $this->module->seeResponseContainsJson(['ticket' => ['labels' => null]]);
+        $this->rest->seeResponseIsJson();
+        $this->rest->seeResponseContainsJson(['name' => 'Davert']);
+        $this->rest->seeResponseContainsJson(['user' => ['name' => 'Davert']]);
+        $this->rest->seeResponseContainsJson(['ticket' => ['title' => 'Bug should be fixed']]);
+        $this->rest->seeResponseContainsJson(['ticket' => ['user' => ['name' => 'Davert']]]);
+        $this->rest->seeResponseContainsJson(['ticket' => ['labels' => null]]);
     }
 
-    public function testSeeInJsonCollection()
+    public function testSeeInJsonCollection(): void
     {
         $this->setStubResponse(
             '[{"user":"Blacknoir","age":27,"tags":["wed-dev","php"]},'
             . '{"user":"John Doe","age":27,"tags":["web-dev","java"]}]'
         );
-        $this->module->seeResponseIsJson();
-        $this->module->seeResponseContainsJson(['tags' => ['web-dev', 'java']]);
-        $this->module->seeResponseContainsJson(['user' => 'John Doe', 'age' => 27]);
+        $this->rest->seeResponseIsJson();
+        $this->rest->seeResponseContainsJson(['tags' => ['web-dev', 'java']]);
+        $this->rest->seeResponseContainsJson(['user' => 'John Doe', 'age' => 27]);
     }
 
-    public function testArrayJson()
+    public function testArrayJson(): void
     {
         $this->setStubResponse(
             '[{"id":1,"title": "Bug should be fixed"},{"title": "Feature should be implemented","id":2}]'
         );
-        $this->module->seeResponseContainsJson(['id' => 1]);
+        $this->rest->seeResponseContainsJson(['id' => 1]);
     }
 
     /**
      * @issue https://github.com/Codeception/Codeception/issues/4202
      */
-    public function testSeeResponseContainsJsonFailsGracefullyWhenJsonResultIsNotArray()
+    public function testSeeResponseContainsJsonFailsGracefullyWhenJsonResultIsNotArray(): void
     {
         $this->shouldFail();
         $this->setStubResponse(json_encode('no_status', JSON_THROW_ON_ERROR));
-        $this->module->seeResponseContainsJson(['id' => 1]);
+        $this->rest->seeResponseContainsJson(['id' => 1]);
     }
 
-    public function testDontSeeResponseJsonMatchesJsonPathPassesWhenJsonResultIsNotArray()
+    public function testDontSeeResponseJsonMatchesJsonPathPassesWhenJsonResultIsNotArray(): void
     {
         $this->setStubResponse(json_encode('no_status', JSON_THROW_ON_ERROR));
-        $this->module->dontSeeResponseJsonMatchesJsonPath('$.error');
+        $this->rest->dontSeeResponseJsonMatchesJsonPath('$.error');
     }
 
-    public function testDontSeeInJson()
+    public function testDontSeeInJson(): void
     {
         $this->setStubResponse('{"ticket": {"title": "Bug should be fixed", "user": {"name": "Davert"}}}');
-        $this->module->seeResponseIsJson();
-        $this->module->dontSeeResponseContainsJson(['name' => 'Davet']);
-        $this->module->dontSeeResponseContainsJson(['user' => ['name' => 'Davet']]);
-        $this->module->dontSeeResponseContainsJson(['user' => ['title' => 'Bug should be fixed']]);
+        $this->rest->seeResponseIsJson();
+        $this->rest->dontSeeResponseContainsJson(['name' => 'Davet']);
+        $this->rest->dontSeeResponseContainsJson(['user' => ['name' => 'Davet']]);
+        $this->rest->dontSeeResponseContainsJson(['user' => ['title' => 'Bug should be fixed']]);
     }
 
-    public function testApplicationJsonIncludesJsonAsContent()
+    public function testApplicationJsonIncludesJsonAsContent(): void
     {
-        $this->module->haveHttpHeader('Content-Type', 'application/json');
-        $this->module->sendPOST('/', ['name' => 'john']);
+        $this->rest->haveHttpHeader('Content-Type', 'application/json');
+        $this->rest->sendPOST('/', ['name' => 'john']);
         /** @var $request SymfonyRequest **/
-        $request = $this->module->client->getRequest();
+        $request = $this->rest->client->getRequest();
         $this->assertContains('application/json', $request->getServer());
         $server = $request->getServer();
         $this->assertEquals('application/json', $server['HTTP_CONTENT_TYPE']);
@@ -170,24 +170,24 @@ public function testApplicationJsonIncludesJsonAsContent()
     /**
      * @issue https://github.com/Codeception/Codeception/issues/3516
      */
-    public function testApplicationJsonHeaderCheckIsCaseInsensitive()
+    public function testApplicationJsonHeaderCheckIsCaseInsensitive(): void
     {
-        $this->module->haveHttpHeader('content-type', 'application/json');
-        $this->module->sendPOST('/', ['name' => 'john']);
+        $this->rest->haveHttpHeader('content-type', 'application/json');
+        $this->rest->sendPOST('/', ['name' => 'john']);
         /** @var $request SymfonyRequest  **/
-        $request = $this->module->client->getRequest();
+        $request = $this->rest->client->getRequest();
         $server = $request->getServer();
         $this->assertEquals('application/json', $server['HTTP_CONTENT_TYPE']);
         $this->assertJson($request->getContent());
         $this->assertEmpty($request->getParameters());
     }
 
-    public function testGetApplicationJsonNotIncludesJsonAsContent()
+    public function testGetApplicationJsonNotIncludesJsonAsContent(): void
     {
-        $this->module->haveHttpHeader('Content-Type', 'application/json');
-        $this->module->sendGET('/', ['name' => 'john']);
+        $this->rest->haveHttpHeader('Content-Type', 'application/json');
+        $this->rest->sendGET('/', ['name' => 'john']);
         /** @var $request SymfonyRequest  **/
-        $request = $this->module->client->getRequest();
+        $request = $this->rest->client->getRequest();
         $this->assertNull($request->getContent());
         $this->assertContains('john', $request->getParameters());
     }
@@ -196,40 +196,40 @@ public function testGetApplicationJsonNotIncludesJsonAsContent()
      * @Issue https://github.com/Codeception/Codeception/issues/2075
      * Client is undefined for the second test
      */
-    public function testTwoTests()
+    public function testTwoTests(): void
     {
         $cest1 = Stub::makeEmpty(Cest::class);
         $cest2 = Stub::makeEmpty(Cest::class);
 
-        $this->module->sendGET('/rest/user/');
-        $this->module->seeResponseIsJson();
-        $this->module->seeResponseContains('davert');
-        $this->module->seeResponseContainsJson(['name' => 'davert']);
-        $this->module->seeResponseCodeIs(200);
-        $this->module->dontSeeResponseCodeIs(404);
+        $this->rest->sendGET('/rest/user/');
+        $this->rest->seeResponseIsJson();
+        $this->rest->seeResponseContains('davert');
+        $this->rest->seeResponseContainsJson(['name' => 'davert']);
+        $this->rest->seeResponseCodeIs(200);
+        $this->rest->dontSeeResponseCodeIs(404);
 
         $this->phpBrowser->_after($cest1);
-        $this->module->_after($cest1);
-        $this->module->_before($cest2);
+        $this->rest->_after($cest1);
+        $this->rest->_before($cest2);
 
         $this->phpBrowser->_before($cest2);
 
-        $this->module->sendGET('/rest/user/');
-        $this->module->seeResponseIsJson();
-        $this->module->seeResponseContains('davert');
-        $this->module->seeResponseContainsJson(['name' => 'davert']);
-        $this->module->seeResponseCodeIs(200);
-        $this->module->dontSeeResponseCodeIs(404);
+        $this->rest->sendGET('/rest/user/');
+        $this->rest->seeResponseIsJson();
+        $this->rest->seeResponseContains('davert');
+        $this->rest->seeResponseContainsJson(['name' => 'davert']);
+        $this->rest->seeResponseCodeIs(200);
+        $this->rest->dontSeeResponseCodeIs(404);
     }
-    
+
     /**
      * @Issue https://github.com/Codeception/Codeception/issues/2070
      */
-    public function testArrayOfZeroesInJsonResponse()
+    public function testArrayOfZeroesInJsonResponse(): void
     {
-        $this->module->haveHttpHeader('Content-Type', 'application/json');
-        $this->module->sendGET('/rest/zeroes');
-        $this->module->dontSeeResponseContainsJson([
+        $this->rest->haveHttpHeader('Content-Type', 'application/json');
+        $this->rest->sendGET('/rest/zeroes');
+        $this->rest->dontSeeResponseContainsJson([
             'responseCode' => 0,
             'data' => [
                 0,
@@ -239,20 +239,20 @@ public function testArrayOfZeroesInJsonResponse()
         ]);
     }
 
-    public function testFileUploadWithKeyValueArray()
+    public function testFileUploadWithKeyValueArray(): void
     {
         $tmpFileName = tempnam('/tmp', 'test_');
         file_put_contents($tmpFileName, 'test data');
         $files = [
             'file' => $tmpFileName,
         ];
-        $this->module->sendPOST('/rest/file-upload', [], $files);
-        $this->module->seeResponseContainsJson([
+        $this->rest->sendPOST('/rest/file-upload', [], $files);
+        $this->rest->seeResponseContainsJson([
             'uploaded' => true,
         ]);
     }
 
-    public function testFileUploadWithFilesArray()
+    public function testFileUploadWithFilesArray(): void
     {
         $tmpFileName = tempnam('/tmp', 'test_');
         file_put_contents($tmpFileName, 'test data');
@@ -264,48 +264,48 @@ public function testFileUploadWithFilesArray()
                 'tmp_name' => $tmpFileName,
             ]
         ];
-        $this->module->sendPOST('/rest/file-upload', [], $files);
-        $this->module->seeResponseContainsJson([
+        $this->rest->sendPOST('/rest/file-upload', [], $files);
+        $this->rest->seeResponseContainsJson([
             'uploaded' => true,
         ]);
     }
 
-    public function testCanInspectResultOfPhpBrowserRequest()
+    public function testCanInspectResultOfPhpBrowserRequest(): void
     {
         $this->phpBrowser->amOnPage('/rest/user/');
-        $this->module->seeResponseCodeIs(200);
-        $this->module->seeResponseIsJson();
+        $this->rest->seeResponseCodeIs(200);
+        $this->rest->seeResponseIsJson();
     }
 
     /**
      * @Issue 4203 https://github.com/Codeception/Codeception/issues/4203
      */
-    public function testSessionHeaderBackup()
+    public function testSessionHeaderBackup(): void
     {
 
-        $this->module->haveHttpHeader('foo', 'bar');
-        $this->module->sendGET('/rest/foo/');
-        $this->module->seeResponseContains('foo: "bar"');
+        $this->rest->haveHttpHeader('foo', 'bar');
+        $this->rest->sendGET('/rest/foo/');
+        $this->rest->seeResponseContains('foo: "bar"');
 
         $session = $this->phpBrowser->_backupSession();
 
-        $this->module->haveHttpHeader('foo', 'baz');
-        $this->module->sendGET('/rest/foo/');
-        $this->module->seeResponseContains('foo: "baz"');
+        $this->rest->haveHttpHeader('foo', 'baz');
+        $this->rest->sendGET('/rest/foo/');
+        $this->rest->seeResponseContains('foo: "baz"');
 
         $this->phpBrowser->_loadSession($session);
-        $this->module->sendGET('/rest/foo/');
-        $this->module->seeResponseContains('foo: "bar"');
+        $this->rest->sendGET('/rest/foo/');
+        $this->rest->seeResponseContains('foo: "bar"');
     }
 
-    protected function shouldFail()
+    private function shouldFail(): void
     {
         $this->expectException(AssertionFailedError::class);
     }
 
-    public function testGrabFromCurrentUrl()
+    public function testGrabFromCurrentUrl(): void
     {
-        $this->module->sendGET('/rest/foo/');
+        $this->rest->sendGET('/rest/foo/');
         $this->assertEquals('/rest/foo/', $this->phpBrowser->grabFromCurrentUrl());
     }
 }
diff --git a/tests/unit/Codeception/Module/PhpBrowserTest.php b/tests/unit/Codeception/Module/PhpBrowserTest.php
index 1d9e39d..aa48e79 100644
--- a/tests/unit/Codeception/Module/PhpBrowserTest.php
+++ b/tests/unit/Codeception/Module/PhpBrowserTest.php
@@ -11,7 +11,7 @@
 use Codeception\Module\PhpBrowser;
 use Codeception\Stub;
 
-require_once 'tests/data/app/data.php';
+require_once dirname(dirname(dirname(__DIR__))) . '/data/app/data.php';
 require_once __DIR__ . '/TestsForBrowsers.php';
 
 use Codeception\Test\Cept;
@@ -26,9 +26,9 @@ final class PhpBrowserTest extends TestsForBrowsers
 {
     protected PhpBrowser $module;
 
-    protected array $history = [];
+    private array $history = [];
 
-    protected function _setUp()
+    protected function _setUp(): void
     {
         $container = Stub::make(ModuleContainer::class);
         $this->module = new PhpBrowser($container);
@@ -37,7 +37,6 @@ protected function _setUp()
         $this->module->_initialize();
         $this->module->_before($this->makeTest());
         $this->module->guzzle->getConfig('handler')->push(GuzzleMiddleware::history($this->history));
-
     }
 
     private function getLastRequest()
@@ -49,7 +48,7 @@ private function getLastRequest()
         return $this->history->getLastRequest();
     }
 
-    protected function _tearDown()
+    protected function _tearDown(): void
     {
         if ($this->module) {
             $this->module->_after($this->makeTest());
@@ -61,12 +60,12 @@ protected function _tearDown()
     /**
      * @return \\Codeception\Test\Cept&\PHPUnit\Framework\MockObject\MockObject
      */
-    protected function makeTest()
+    private function makeTest()
     {
         return Stub::makeEmpty(Cept::class);
     }
 
-    public function testAjax()
+    public function testAjax(): void
     {
         $this->module->amOnPage('/');
         $this->module->sendAjaxGetRequest('/info');
@@ -78,32 +77,32 @@ public function testAjax()
         $this->assertEquals('author', $post['show']);
     }
 
-    public function testLinksWithNonLatin()
+    public function testLinksWithNonLatin(): void
     {
         $this->module->amOnPage('/info');
         $this->module->seeLink('Ссылочка');
         $this->module->click('Ссылочка');
     }
 
-    public function testHtmlSnapshot()
+    public function testHtmlSnapshot(): void
     {
         $this->module->amOnPage('/');
-        $testName="debugPhpBrowser";
+        $testName = "debugPhpBrowser";
         $this->module->makeHtmlSnapshot($testName);
-        $this->assertFileExists(CodeceptConfig::outputDir().'debug/'.$testName.'.html');
-        @unlink(CodeceptConfig::outputDir().'debug/'.$testName.'.html');
+        $this->assertFileExists(CodeceptConfig::outputDir() . 'debug/' . $testName . '.html');
+        @unlink(CodeceptConfig::outputDir() . 'debug/' . $testName . '.html');
     }
 
     /**
      * @see https://github.com/Codeception/Codeception/issues/4509
      */
-    public function testSeeTextAfterJSComparisionOperator()
+    public function testSeeTextAfterJSComparisionOperator(): void
     {
         $this->module->amOnPage('/info');
         $this->module->see('Text behind JS comparision');
     }
 
-    public function testSetMultipleCookies()
+    public function testSetMultipleCookies(): void
     {
         $this->module->amOnPage('/');
         $cookie_name_1  = 'test_cookie';
@@ -131,7 +130,7 @@ public function testSetMultipleCookies()
         $this->module->dontSeeCookie($cookie_name_2);
     }
 
-    public function testSessionsHaveIndependentCookies()
+    public function testSessionsHaveIndependentCookies(): void
     {
         $this->module->amOnPage('/');
         $cookie_name_1  = 'test_cookie';
@@ -153,7 +152,7 @@ public function testSessionsHaveIndependentCookies()
         $this->module->seeCookie($cookie_name_1);
     }
 
-    public function testSubmitFormGet()
+    public function testSubmitFormGet(): void
     {
         $I = $this->module;
         $I->amOnPage('/search');
@@ -161,7 +160,7 @@ public function testSubmitFormGet()
         $I->see('Success');
     }
 
-    public function testHtmlRedirect()
+    public function testHtmlRedirect(): void
     {
         $this->module->amOnPage('/redirect2');
         $this->module->seeResponseCodeIs(200);
@@ -171,21 +170,21 @@ public function testHtmlRedirect()
         $this->module->seeCurrentUrlEquals('/redirect_interval');
     }
 
-    public function testHtmlRedirectWithParams()
+    public function testHtmlRedirectWithParams(): void
     {
         $this->module->amOnPage('/redirect_params');
         $this->module->seeResponseCodeIs(200);
         $this->module->seeCurrentUrlEquals('/search?one=1&two=2');
     }
 
-    public function testMetaRefresh()
+    public function testMetaRefresh(): void
     {
         $this->module->amOnPage('/redirect_meta_refresh');
         $this->module->seeResponseCodeIs(200);
         $this->module->seeCurrentUrlEquals('/info');
     }
 
-    public function testMetaRefreshIsIgnoredIfIntervalIsLongerThanMaxInterval()
+    public function testMetaRefreshIsIgnoredIfIntervalIsLongerThanMaxInterval(): void
     {
         // prepare config
         $config = $this->module->_getConfig();
@@ -196,7 +195,7 @@ public function testMetaRefreshIsIgnoredIfIntervalIsLongerThanMaxInterval()
         $this->module->seeCurrentUrlEquals('/redirect_meta_refresh');
     }
 
-    public function testRefreshRedirect()
+    public function testRefreshRedirect(): void
     {
         $this->module->amOnPage('/redirect3');
         $this->module->seeResponseCodeIs(200);
@@ -207,7 +206,7 @@ public function testRefreshRedirect()
         $this->module->see('Welcome to test app!');
     }
 
-    public function testRedirectWithGetParams()
+    public function testRedirectWithGetParams(): void
     {
         $this->module->amOnPage('/redirect4');
         $this->module->seeInCurrentUrl('/search?ln=test@gmail.com&sn=testnumber');
@@ -216,7 +215,7 @@ public function testRedirectWithGetParams()
         $this->assertContains('test@gmail.com', $params);
     }
 
-    public function testRedirectBaseUriHasPath()
+    public function testRedirectBaseUriHasPath(): void
     {
         // prepare config
         $config = $this->module->_getConfig();
@@ -229,7 +228,7 @@ public function testRedirectBaseUriHasPath()
         $this->module->see('Lots of valuable data here');
     }
 
-    public function testRedirectBaseUriHasPathAnd302Code()
+    public function testRedirectBaseUriHasPathAnd302Code(): void
     {
         // prepare config
         $config = $this->module->_getConfig();
@@ -242,7 +241,7 @@ public function testRedirectBaseUriHasPathAnd302Code()
         $this->module->see('Lots of valuable data here');
     }
 
-    public function testRelativeRedirect()
+    public function testRelativeRedirect(): void
     {
         // test relative redirects where the effective request URI is in a
         // subdirectory
@@ -257,14 +256,14 @@ public function testRelativeRedirect()
         $this->module->seeCurrentUrlEquals('/info');
     }
 
-    public function testChainedRedirects()
+    public function testChainedRedirects(): void
     {
         $this->module->amOnPage('/redirect_twice');
         $this->module->seeResponseCodeIs(200);
         $this->module->seeCurrentUrlEquals('/info');
     }
 
-    public function testDisabledRedirects()
+    public function testDisabledRedirects(): void
     {
         $this->module->client->followRedirects(false);
         $this->module->amOnPage('/redirect_twice');
@@ -272,22 +271,22 @@ public function testDisabledRedirects()
         $this->module->seeCurrentUrlEquals('/redirect_twice');
     }
 
-    public function testRedirectLimitReached()
+    public function testRedirectLimitReached(): void
     {
         $this->module->client->setMaxRedirects(1);
         try {
             $this->module->amOnPage('/redirect_twice');
             $this->fail('redirect limit is not respected');
-        } catch (LogicException $exception) {
+        } catch (LogicException $logicException) {
             $this->assertEquals(
                 'The maximum number (1) of redirections was reached.',
-                $exception->getMessage(),
+                $logicException->getMessage(),
                 'redirect limit is respected'
             );
         }
     }
 
-    public function testRedirectLimitNotReached()
+    public function testRedirectLimitNotReached(): void
     {
         $this->module->client->setMaxRedirects(2);
         $this->module->amOnPage('/redirect_twice');
@@ -295,14 +294,14 @@ public function testRedirectLimitNotReached()
         $this->module->seeCurrentUrlEquals('/info');
     }
 
-    public function testLocationHeaderDoesNotRedirectWhenStatusCodeIs201()
+    public function testLocationHeaderDoesNotRedirectWhenStatusCodeIs201(): void
     {
         $this->module->amOnPage('/location_201');
         $this->module->seeResponseCodeIs(201);
         $this->module->seeCurrentUrlEquals('/location_201');
     }
 
-    public function testRedirectToAnotherDomainUsingSchemalessUrl()
+    public function testRedirectToAnotherDomainUsingSchemalessUrl(): void
     {
 
         $this->module->_reconfigure([
@@ -311,14 +310,13 @@ public function testRedirectToAnotherDomainUsingSchemalessUrl()
                 new Response(200, [], 'Cool stuff')
             ])
         ]);
-        /** @var GuzzleHandlerStack $handlerStack */
         $this->module->amOnUrl('http://fictional.redirector/redirect-to?url=//example.org/');
 
         $currentUrl = $this->module->client->getHistory()->current()->getUri();
         $this->assertSame('http://example.org/', $currentUrl);
     }
 
-    public function testSetCookieByHeader()
+    public function testSetCookieByHeader(): void
     {
         $this->module->amOnPage('/cookies2');
         $this->module->seeResponseCodeIs(200);
@@ -327,14 +325,14 @@ public function testSetCookieByHeader()
         $this->module->seeCookie('c');
     }
 
-    public function testSettingContentTypeFromHtml()
+    public function testSettingContentTypeFromHtml(): void
     {
         $this->module->amOnPage('/content-iso');
         $charset = $this->module->client->getResponse()->getHeader('Content-Type');
         $this->assertEquals('text/html;charset=ISO-8859-1', $charset);
     }
 
-    public function testSettingCharsetFromHtml()
+    public function testSettingCharsetFromHtml(): void
     {
         $this->module->amOnPage('/content-cp1251');
         $charset = $this->module->client->getResponse()->getHeader('Content-Type');
@@ -344,7 +342,7 @@ public function testSettingCharsetFromHtml()
     /**
      * @Issue https://github.com/Codeception/Codeception/issues/933
      */
-    public function testSubmitFormWithQueries()
+    public function testSubmitFormWithQueries(): void
     {
         $this->module->amOnPage('/form/example3');
         $this->module->seeElement('form');
@@ -356,14 +354,14 @@ public function testSubmitFormWithQueries()
         $this->module->seeCurrentUrlEquals('/form/example3?validate=yes');
     }
 
-    public function testHeadersBySetHeader()
+    public function testHeadersBySetHeader(): void
     {
         $this->module->setHeader('xxx', 'yyyy');
         $this->module->amOnPage('/');
         $this->assertTrue($this->getLastRequest()->hasHeader('xxx'));
     }
 
-    public function testDeleteHeaders()
+    public function testDeleteHeaders(): void
     {
         $this->module->setHeader('xxx', 'yyyy');
         $this->module->deleteHeader('xxx');
@@ -371,7 +369,7 @@ public function testDeleteHeaders()
         $this->assertFalse($this->getLastRequest()->hasHeader('xxx'));
     }
 
-    public function testDeleteHeadersByEmptyValue()
+    public function testDeleteHeadersByEmptyValue(): void
     {
         $this->module->setHeader('xxx', 'yyyy');
         $this->module->setHeader('xxx', '');
@@ -379,7 +377,7 @@ public function testDeleteHeadersByEmptyValue()
         $this->assertFalse($this->getLastRequest()->hasHeader('xxx'));
     }
 
-    public function testCurlOptions()
+    public function testCurlOptions(): void
     {
         $this->module->_setConfig(['url' => 'http://google.com', 'curl' => ['CURLOPT_NOBODY' => true]]);
         $this->module->_initialize();
@@ -394,7 +392,7 @@ public function testCurlOptions()
     }
 
 
-    public function testCurlSslOptions()
+    public function testCurlSslOptions(): void
     {
         $this->module->_setConfig([
             'url' => 'https://github.com',
@@ -412,7 +410,7 @@ public function testCurlSslOptions()
         $this->assertSame('', $this->module->_getResponseContent(), 'CURLOPT_NOBODY setting is not respected');
     }
 
-    public function testHttpAuth()
+    public function testHttpAuth(): void
     {
         $this->module->amOnPage('/auth');
         $this->module->seeResponseCodeIs(401);
@@ -430,11 +428,11 @@ public function testHttpAuth()
         $this->module->see('Forbidden');
     }
 
-    public function testRawGuzzle()
+    public function testRawGuzzle(): void
     {
-        $code = $this->module->executeInGuzzle(function (GuzzleClient $client): int {
-            $res = $client->get('/info');
-            return $res->getStatusCode();
+        $code = $this->module->executeInGuzzle(function (GuzzleClient $guzzleClient): int {
+            $response = $guzzleClient->get('/info');
+            return $response->getStatusCode();
         });
         $this->assertEquals(200, $code);
     }
@@ -459,7 +457,7 @@ public function testRawGuzzle()
      * this will check if current element contains inner arrays within it's keys
      * so we can ignore element itself and only process inner files
      */
-    public function testFormWithFilesInOnlyArray()
+    public function testFormWithFilesInOnlyArray(): void
     {
         $this->shouldFail();
         $this->module->amOnPage('/form/example13');
@@ -468,7 +466,7 @@ public function testFormWithFilesInOnlyArray()
         $this->module->click('Submit');
     }
 
-    public function testDoubleSlash()
+    public function testDoubleSlash(): void
     {
         $I = $this->module;
         $I->amOnPage('/register');
@@ -479,13 +477,13 @@ public function testDoubleSlash()
         $this->assertEquals($formPath, '/register');
     }
 
-    public function testFillFieldWithoutPage()
+    public function testFillFieldWithoutPage(): void
     {
         $this->expectException(ModuleException::class);
         $this->module->fillField('#name', 'Nothing special');
     }
 
-    public function testArrayFieldSubmitForm()
+    public function testArrayFieldSubmitForm(): void
     {
         $this->module->amOnPage('/form/example17');
         $this->module->submitForm(
@@ -504,19 +502,19 @@ public function testArrayFieldSubmitForm()
         $this->assertEquals('crunked', $data['Food']['beer']['yum']['yeah']);
     }
 
-    public function testCookiesForDomain()
+    public function testCookiesForDomain(): void
     {
-        $mock = new MockHandler([
+        $mockHandler = new MockHandler([
             new Response(200, ['X-Foo' => 'Bar']),
         ]);
-        $handler = GuzzleHandlerStack::create($mock);
-        $handler->push(GuzzleMiddleware::history($this->history));
-
-        $client = new GuzzleClient(['handler' => $handler, 'base_uri' => 'https://codeception.com']);
-        $guzzleConnector = new Guzzle();
-        $guzzleConnector->setClient($client);
-        $guzzleConnector->getCookieJar()->set(new Cookie('hello', 'world'));
-        $guzzleConnector->request('GET', 'https://codeception.com/');
+        $guzzleHandlerStack = GuzzleHandlerStack::create($mockHandler);
+        $guzzleHandlerStack->push(GuzzleMiddleware::history($this->history));
+
+        $client = new GuzzleClient(['handler' => $guzzleHandlerStack, 'base_uri' => 'https://codeception.com']);
+        $guzzle = new Guzzle();
+        $guzzle->setClient($client);
+        $guzzle->getCookieJar()->set(new Cookie('hello', 'world'));
+        $guzzle->request('GET', 'https://codeception.com/');
         $this->assertArrayHasKey('cookies', $this->history[0]['options']);
         /** @var $cookie GuzzleHttp\Cookie\SetCookie  **/
         $cookies = $this->history[0]['options']['cookies']->toArray();
@@ -527,7 +525,7 @@ public function testCookiesForDomain()
     /**
      * @issue https://github.com/Codeception/Codeception/issues/2653
      */
-    public function testSetCookiesByOptions()
+    public function testSetCookiesByOptions(): void
     {
         $config = $this->module->_getConfig();
         $config['cookies'] = [
@@ -549,7 +547,7 @@ public function testSetCookiesByOptions()
     /**
      * @issue https://github.com/Codeception/Codeception/issues/2234
      */
-    public function testEmptyValueOfCookie()
+    public function testEmptyValueOfCookie(): void
     {
         //set cookie
         $this->module->amOnPage('/cookies2');
@@ -559,7 +557,7 @@ public function testEmptyValueOfCookie()
         $this->module->dontSeeCookie('a');
     }
 
-    public function testRequestApi()
+    public function testRequestApi(): void
     {
         $this->expectException(ModuleException::class);
         $response = $this->module->_request('POST', '/form/try', ['user' => 'davert']);
@@ -570,7 +568,7 @@ public function testRequestApi()
         $this->module->click('Welcome to test app'); // page not loaded
     }
 
-    public function testLoadPageApi()
+    public function testLoadPageApi(): void
     {
         $this->module->_loadPage('POST', '/form/try', ['user' => 'davert']);
         $data = data::get('form');
@@ -583,7 +581,7 @@ public function testLoadPageApi()
     /**
      * @issue https://github.com/Codeception/Codeception/issues/2408
      */
-    public function testClickFailure()
+    public function testClickFailure(): void
     {
         $this->module->amOnPage('/info');
         $this->expectException(ElementNotFound::class);
@@ -594,7 +592,7 @@ public function testClickFailure()
     /**
      * @issue https://github.com/Codeception/Codeception/issues/2841
      */
-    public function testSubmitFormDoesNotKeepGetParameters()
+    public function testSubmitFormDoesNotKeepGetParameters(): void
     {
         $this->module->amOnPage('/form/bug2841?stuff=other');
         $this->module->fillField('#texty', 'thingshjere');
@@ -602,7 +600,7 @@ public function testSubmitFormDoesNotKeepGetParameters()
         $this->assertEmpty(data::get('query'), 'Query string is not empty');
     }
 
-    public function testClickLinkAndFillField()
+    public function testClickLinkAndFillField(): void
     {
         $this->module->amOnPage('/info');
         $this->module->click('Sign in!');
@@ -610,21 +608,21 @@ public function testClickLinkAndFillField()
         $this->module->fillField('email', 'email@example.org');
     }
 
-    public function testClickSelectsClickableElementFromMatches()
+    public function testClickSelectsClickableElementFromMatches(): void
     {
         $this->module->amOnPage('/form/multiple_matches');
         $this->module->click('Press Me!');
         $this->module->seeCurrentUrlEquals('/info');
     }
 
-    public function testClickSelectsClickableElementFromMatchesUsingCssLocator()
+    public function testClickSelectsClickableElementFromMatchesUsingCssLocator(): void
     {
         $this->module->amOnPage('/form/multiple_matches');
         $this->module->click(['css' => '.link']);
         $this->module->seeCurrentUrlEquals('/info');
     }
 
-    public function testClickingOnButtonOutsideFormDoesNotCauseFatalError()
+    public function testClickingOnButtonOutsideFormDoesNotCauseFatalError(): void
     {
         $this->expectException(TestRuntimeException::class);
         $this->expectExceptionMessage('Button is not inside a link or a form');
@@ -632,7 +630,7 @@ public function testClickingOnButtonOutsideFormDoesNotCauseFatalError()
         $this->module->click('Submit 2');
     }
 
-    public function testSubmitFormWithoutEmptyOptionsInSelect()
+    public function testSubmitFormWithoutEmptyOptionsInSelect(): void
     {
         $this->module->amOnPage('/form/bug3824');
         $this->module->submitForm('form', []);
@@ -642,7 +640,7 @@ public function testSubmitFormWithoutEmptyOptionsInSelect()
     /**
      * @issue https://github.com/Codeception/Codeception/issues/3953
      */
-    public function testFillFieldInGetFormWithoutId()
+    public function testFillFieldInGetFormWithoutId(): void
     {
         $this->module->amOnPage('/form/bug3953');
         $this->module->selectOption('select_name', 'two');
@@ -654,18 +652,18 @@ public function testFillFieldInGetFormWithoutId()
         $this->assertEquals('searchterm', $params['search_name']);
     }
 
-    public function testGrabPageSourceWhenNotOnPage()
+    public function testGrabPageSourceWhenNotOnPage(): void
     {
         $this->expectException(ModuleException::class);
         $this->expectExceptionMessage('Page not loaded. Use `$I->amOnPage` (or hidden API methods `_request` and `_loadPage`) to open it');
         $this->module->grabPageSource();
     }
 
-    public function testGrabPageSourceWhenOnPage()
+    public function testGrabPageSourceWhenOnPage(): void
     {
         $this->module->amOnPage('/minimal');
         $sourceExpected =
-<<<HTML
+        <<<HTML
 <!DOCTYPE html>
 <html>
     <head>
@@ -689,7 +687,7 @@ public function testGrabPageSourceWhenOnPage()
     /**
      * @issue https://github.com/Codeception/Codeception/issues/4383
      */
-    public function testSecondAmOnUrlWithEmptyPath()
+    public function testSecondAmOnUrlWithEmptyPath(): void
     {
         $this->module->amOnUrl('http://localhost:8000/info');
         $this->module->see('Lots of valuable data here');
@@ -697,7 +695,7 @@ public function testSecondAmOnUrlWithEmptyPath()
         $this->module->dontSee('Lots of valuable data here');
     }
 
-    public function testSetUserAgentUsingConfig()
+    public function testSetUserAgentUsingConfig(): void
     {
         $this->module->_setConfig(['headers' => ['User-Agent' => 'Codeception User Agent Test 1.0']]);
         $this->module->_initialize();
@@ -708,7 +706,7 @@ public function testSetUserAgentUsingConfig()
         $this->assertEquals('Codeception User Agent Test 1.0', $response, 'Incorrect user agent');
     }
 
-    public function testIfStatusCodeIsWithin2xxRange()
+    public function testIfStatusCodeIsWithin2xxRange(): void
     {
         $this->module->amOnPage('https://httpstat.us/200');
         $this->module->seeResponseCodeIsSuccessful();
@@ -717,7 +715,7 @@ public function testIfStatusCodeIsWithin2xxRange()
         $this->module->seeResponseCodeIsSuccessful();
     }
 
-    public function testIfStatusCodeIsWithin3xxRange()
+    public function testIfStatusCodeIsWithin3xxRange(): void
     {
         $this->module->amOnPage('https://httpstat.us/300');
         $this->module->seeResponseCodeIsRedirection();
@@ -726,7 +724,7 @@ public function testIfStatusCodeIsWithin3xxRange()
         $this->module->seeResponseCodeIsRedirection();
     }
 
-    public function testIfStatusCodeIsWithin4xxRange()
+    public function testIfStatusCodeIsWithin4xxRange(): void
     {
         $this->module->amOnPage('https://httpstat.us/400');
         $this->module->seeResponseCodeIsClientError();
@@ -735,7 +733,7 @@ public function testIfStatusCodeIsWithin4xxRange()
         $this->module->seeResponseCodeIsClientError();
     }
 
-    public function testIfStatusCodeIsWithin5xxRange()
+    public function testIfStatusCodeIsWithin5xxRange(): void
     {
         $this->module->amOnPage('https://httpstat.us/500');
         $this->module->seeResponseCodeIsServerError();
@@ -747,7 +745,7 @@ public function testIfStatusCodeIsWithin5xxRange()
     /**
      * @issue https://github.com/Codeception/Codeception/issues/5547
      */
-    public function testSelectOptionByTextWhenItHasNoValue()
+    public function testSelectOptionByTextWhenItHasNoValue(): void
     {
         $this->module->amOnPage('/form/bug5547');
         $this->module->selectOption('#_payment_type', 'qwerty');
diff --git a/tests/unit/Codeception/Module/TestsForBrowsers.php b/tests/unit/Codeception/Module/TestsForBrowsers.php
index 3edac74..e5ca192 100644
--- a/tests/unit/Codeception/Module/TestsForBrowsers.php
+++ b/tests/unit/Codeception/Module/TestsForBrowsers.php
@@ -4,7 +4,7 @@
 
 use Codeception\Exception\ModuleException;
 
-require_once 'TestsForWeb.php';
+require_once __DIR__ . '/TestsForWeb.php';
 
 /**
  * Author: davert
@@ -14,8 +14,7 @@
  */
 abstract class TestsForBrowsers extends TestsForWeb
 {
-   
-    public function testAmOnSubdomain()
+    public function testAmOnSubdomain(): void
     {
         $this->module->_reconfigure(['url' => 'https://google.com']);
         $this->module->amOnSubdomain('user');
@@ -26,7 +25,7 @@ public function testAmOnSubdomain()
         $this->assertEquals('https://user.google.com', $this->module->_getUrl());
     }
 
-    public function testOpenAbsoluteUrls()
+    public function testOpenAbsoluteUrls(): void
     {
         $this->module->amOnUrl('http://localhost:8000/');
         $this->module->see('Welcome to test app!', 'h1');
@@ -37,7 +36,7 @@ public function testOpenAbsoluteUrls()
         $this->assertEquals('http://127.0.0.1:8000', $this->module->_getUrl(), 'Host has changed');
     }
 
-    public function testHeadersRedirect()
+    public function testHeadersRedirect(): void
     {
         $this->module->amOnPage('/redirect');
         $this->module->seeInCurrentUrl('info');
@@ -46,7 +45,7 @@ public function testHeadersRedirect()
     /*
      * https://github.com/Codeception/Codeception/issues/1510
      */
-    public function testSiteRootRelativePathsForBasePathWithSubdir()
+    public function testSiteRootRelativePathsForBasePathWithSubdir(): void
     {
         $this->module->_reconfigure(['url' => 'http://localhost:8000/form']);
         $this->module->amOnPage('/relative_siteroot');
@@ -60,7 +59,7 @@ public function testSiteRootRelativePathsForBasePathWithSubdir()
         $this->module->dontSeeInCurrentUrl('form/form/');
     }
 
-    public function testOpenPageException()
+    public function testOpenPageException(): void
     {
         $this->expectException(ModuleException::class);
         $this->module->see('Hello');
diff --git a/tests/unit/Codeception/Module/TestsForWeb.php b/tests/unit/Codeception/Module/TestsForWeb.php
index a15e114..a07d202 100644
--- a/tests/unit/Codeception/Module/TestsForWeb.php
+++ b/tests/unit/Codeception/Module/TestsForWeb.php
@@ -19,7 +19,7 @@ abstract class TestsForWeb extends Unit
 {
     protected PhpBrowser $module;
 
-    public function testAmOnPage()
+    public function testAmOnPage(): void
     {
         $this->module->amOnPage('/');
         $this->module->see('Welcome to test app!');
@@ -28,7 +28,7 @@ public function testAmOnPage()
         $this->module->see('Information');
     }
 
-    public function testCurrentUrl()
+    public function testCurrentUrl(): void
     {
         $this->module->amOnPage('/info');
         $this->module->seeCurrentUrlEquals('/info');
@@ -45,7 +45,7 @@ public function testCurrentUrl()
     }
 
 
-    public function testSee()
+    public function testSee(): void
     {
         $this->module->amOnPage('/');
         $this->module->see('Welcome to test app!');
@@ -70,14 +70,14 @@ public function testSee()
         $this->module->dontSee('Welcome', 'h6');
     }
 
-    public function testDontSeeFailsWhenMultilineTextMatches()
+    public function testDontSeeFailsWhenMultilineTextMatches(): void
     {
         $this->shouldFail();
         $this->module->amOnPage('/');
         $this->module->dontSee('Some text with formatting on separate lines');
     }
 
-    public function testDontSeeFailsWhenMultilineTextMatchesInSelector()
+    public function testDontSeeFailsWhenMultilineTextMatchesInSelector(): void
     {
         $this->shouldFail();
         $this->module->amOnPage('/');
@@ -87,21 +87,21 @@ public function testDontSeeFailsWhenMultilineTextMatchesInSelector()
     /**
      * @Issue https://github.com/Codeception/Codeception/issues/3114
      */
-    public function testSeeIsCaseInsensitiveForUnicodeText()
+    public function testSeeIsCaseInsensitiveForUnicodeText(): void
     {
         $this->module->amOnPage('/info');
         $this->module->see('ссылочка');
         $this->module->see('ссылочка', 'a');
     }
 
-    public function testDontSeeIsCaseInsensitiveForUnicodeText()
+    public function testDontSeeIsCaseInsensitiveForUnicodeText(): void
     {
         $this->expectException(AssertionFailedError::class);
         $this->module->amOnPage('/info');
         $this->module->dontSee('ссылочка');
     }
 
-    public function testSeeInSource()
+    public function testSeeInSource(): void
     {
         $this->module->amOnPage('/');
         $this->module->seeInSource('<h1>Welcome to test app!</h1>');
@@ -109,13 +109,13 @@ public function testSeeInSource()
         $this->module->dontSeeInSource('John Cleese');
     }
 
-    public function testSeeInCurrentUrl()
+    public function testSeeInCurrentUrl(): void
     {
         $this->module->amOnPage('/info');
         $this->module->seeInCurrentUrl('/info');
     }
 
-    public function testSeeLink()
+    public function testSeeLink(): void
     {
         $this->module->amOnPage('/external_url');
         $this->module->seeLink('Next');
@@ -124,14 +124,14 @@ public function testSeeLink()
         $this->module->dontSeeLink('Next', 'https://codeception');
     }
 
-    public function testDontSeeLink()
+    public function testDontSeeLink(): void
     {
         $this->module->amOnPage('/external_url');
         $this->module->dontSeeLink('Back');
         $this->module->dontSeeLink('Next', '/fsdfsdf/');
     }
 
-    public function testSeeLinkFailsIfTextDoesNotMatch()
+    public function testSeeLinkFailsIfTextDoesNotMatch(): void
     {
         $this->expectException(AssertionFailedError::class);
         $this->expectExceptionMessage("No links containing text 'Codeception' were found in page /external_url");
@@ -139,7 +139,7 @@ public function testSeeLinkFailsIfTextDoesNotMatch()
         $this->module->seeLink('Codeception');
     }
 
-    public function testSeeLinkFailsIfHrefDoesNotMatch()
+    public function testSeeLinkFailsIfHrefDoesNotMatch(): void
     {
         $this->expectException(AssertionFailedError::class);
         $this->expectExceptionMessage("No links containing text 'Next' and URL '/fsdfsdf/' were found in page /external_url");
@@ -147,7 +147,7 @@ public function testSeeLinkFailsIfHrefDoesNotMatch()
         $this->module->seeLink('Next', '/fsdfsdf/');
     }
 
-    public function testSeeLinkFailsIfHrefDoesNotMatchExactly()
+    public function testSeeLinkFailsIfHrefDoesNotMatchExactly(): void
     {
         $this->expectException(AssertionFailedError::class);
         $this->expectExceptionMessage("No links containing text 'Next' and URL 'https://codeception' were found in page /external_url");
@@ -155,7 +155,7 @@ public function testSeeLinkFailsIfHrefDoesNotMatchExactly()
         $this->module->seeLink('Next', 'https://codeception');
     }
 
-    public function testDontSeeLinkFailsIfTextMatches()
+    public function testDontSeeLinkFailsIfTextMatches(): void
     {
         $this->expectException(AssertionFailedError::class);
         $this->expectExceptionMessage("Link containing text 'Next' was found in page /external_url");
@@ -163,7 +163,7 @@ public function testDontSeeLinkFailsIfTextMatches()
         $this->module->dontSeeLink('Next');
     }
 
-    public function testDontSeeLinkFailsIfTextAndUrlMatches()
+    public function testDontSeeLinkFailsIfTextAndUrlMatches(): void
     {
         $this->expectException(AssertionFailedError::class);
         $this->expectExceptionMessage("Link containing text 'Next' and URL 'https://codeception.com/' was found in page /external_url");
@@ -171,14 +171,14 @@ public function testDontSeeLinkFailsIfTextAndUrlMatches()
         $this->module->dontSeeLink('Next', 'https://codeception.com/');
     }
 
-    public function testSeeLinkMatchesRelativeLink()
+    public function testSeeLinkMatchesRelativeLink(): void
     {
         $this->module->amOnPage('/info');
         $this->module->seeLink('Sign in!', '/login');
         $this->module->dontSeeLink('Sign in!', '/log');
     }
 
-    public function testDontSeeLinkMatchesRelativeLink()
+    public function testDontSeeLinkMatchesRelativeLink(): void
     {
         $this->expectException(AssertionFailedError::class);
         $this->expectExceptionMessage("Link containing text 'Sign in!' and URL '/login' was found in page /info");
@@ -186,7 +186,7 @@ public function testDontSeeLinkMatchesRelativeLink()
         $this->module->dontSeeLink('Sign in!', '/login');
     }
 
-    public function testClick()
+    public function testClick(): void
     {
         $this->module->amOnPage('/');
         $this->module->click('More info');
@@ -201,7 +201,7 @@ public function testClick()
         $this->module->seeInCurrentUrl('/info');
     }
 
-    public function testClickByName()
+    public function testClickByName(): void
     {
         $this->module->amOnPage('/form/button');
         $this->module->click("btn0");
@@ -210,14 +210,14 @@ public function testClickByName()
         $this->assertEquals('val', $form['text']);
     }
 
-    public function testClickByLinkTitle()
+    public function testClickByLinkTitle(): void
     {
         $this->module->amOnPage('/');
         $this->module->click("Link Title");
         $this->module->seeInCurrentUrl('/info');
     }
 
-    public function testClickOnContext()
+    public function testClickOnContext(): void
     {
         $this->module->amOnPage('/');
         $this->module->click('More info', 'p');
@@ -228,7 +228,7 @@ public function testClickOnContext()
         $this->module->seeInCurrentUrl('/info');
     }
 
-    public function testCheckboxByCss()
+    public function testCheckboxByCss(): void
     {
         $this->module->amOnPage('/form/checkbox');
         $this->module->checkOption('#checkin');
@@ -238,7 +238,7 @@ public function testCheckboxByCss()
         $this->assertEquals('agree', $form['terms']);
     }
 
-    public function testCheckboxByName()
+    public function testCheckboxByName(): void
     {
         $this->module->amOnPage('/form/checkbox');
         $this->module->checkOption('terms');
@@ -248,7 +248,7 @@ public function testCheckboxByName()
         $this->assertEquals('agree', $form['terms']);
     }
 
-    public function testCheckboxByLabel()
+    public function testCheckboxByLabel(): void
     {
         $this->module->amOnPage('/form/checkbox');
         $this->module->checkOption('I Agree');
@@ -262,7 +262,7 @@ public function testCheckboxByLabel()
      * @group testCheckboxArray
      * @Issue https://github.com/Codeception/Codeception/pull/1145
      */
-    public function testCheckboxArray()
+    public function testCheckboxArray(): void
     {
         $this->module->amOnPage('/form/checkbox_array');
         $this->module->checkOption('#id2');
@@ -272,7 +272,7 @@ public function testCheckboxArray()
         $this->assertEquals('second', reset($form['field']));
     }
 
-    public function testSelectByCss()
+    public function testSelectByCss(): void
     {
         $this->module->amOnPage('/form/select');
         $this->module->selectOption('form select[name=age]', 'adult');
@@ -282,7 +282,7 @@ public function testSelectByCss()
         $this->assertEquals('adult', $form['age']);
     }
 
-    public function testSelectByName()
+    public function testSelectByName(): void
     {
         $this->module->amOnPage('/form/select');
         $this->module->selectOption('age', 'adult');
@@ -292,7 +292,7 @@ public function testSelectByName()
         $this->assertEquals('adult', $form['age']);
     }
 
-    public function testSelectByLabel()
+    public function testSelectByLabel(): void
     {
         $this->module->amOnPage('/form/select');
         $this->module->selectOption('Select your age', 'dead');
@@ -302,7 +302,7 @@ public function testSelectByLabel()
         $this->assertEquals('dead', $form['age']);
     }
 
-    public function testSelectByLabelAndOptionText()
+    public function testSelectByLabelAndOptionText(): void
     {
         $this->module->amOnPage('/form/select');
         $this->module->selectOption('Select your age', '21-60');
@@ -312,14 +312,14 @@ public function testSelectByLabelAndOptionText()
         $this->assertEquals('adult', $form['age']);
     }
 
-    public function testSeeSelectedOption()
+    public function testSeeSelectedOption(): void
     {
         $this->module->amOnPage('/form/select');
         $this->module->seeOptionIsSelected('#age', '60-100');
         $this->module->dontSeeOptionIsSelected('#age', '100-210');
     }
 
-    public function testSeeSelectedOptionForRadioButton()
+    public function testSeeSelectedOptionForRadioButton(): void
     {
         $this->module->amOnPage('/form/example6');
         $this->module->seeOptionIsSelected('input[name=frequency]', 'hour');
@@ -329,7 +329,7 @@ public function testSeeSelectedOptionForRadioButton()
     /**
      * @Issue https://github.com/Codeception/Codeception/issues/2733
      */
-    public function testSeeSelectedOptionReturnsFirstOptionIfNotSelected()
+    public function testSeeSelectedOptionReturnsFirstOptionIfNotSelected(): void
     {
         $this->module->amOnPage('/form/complex');
         $this->module->seeOptionIsSelected('#age', 'below 13');
@@ -343,7 +343,7 @@ public function testSeeSelectedOptionReturnsFirstOptionIfNotSelected()
      * @group testSubmitSeveralSubmitsForm
      * @Issue https://github.com/Codeception/Codeception/issues/1183
      */
-    public function testSubmitSeveralSubmitsForm()
+    public function testSubmitSeveralSubmitsForm(): void
     {
         $this->module->amOnPage('/form/example8');
         $this->module->click('form button[value="second"]');
@@ -358,7 +358,7 @@ public function testSubmitSeveralSubmitsForm()
      * @group testSubmitSeveralSubmitsForm
      * @Issue https://github.com/Codeception/Codeception/issues/1183
      */
-    public function testSubmitLotsOfSubmitsForm()
+    public function testSubmitLotsOfSubmitsForm(): void
     {
         $this->module->amOnPage('/form/example11');
         $this->module->click('form button[value="fifth"]');
@@ -367,7 +367,7 @@ public function testSubmitLotsOfSubmitsForm()
         $this->assertEquals('fifth', $form['submit']);
     }
 
-    public function testSelectMultipleOptionsByText()
+    public function testSelectMultipleOptionsByText(): void
     {
         $this->module->amOnPage('/form/select_multiple');
         $this->module->selectOption('What do you like the most?', ['Play Video Games', 'Have Sex']);
@@ -377,7 +377,7 @@ public function testSelectMultipleOptionsByText()
         $this->assertEquals(['play', 'adult'], $form['like']);
     }
 
-    public function testSelectMultipleOptionsByValue()
+    public function testSelectMultipleOptionsByValue(): void
     {
         $this->module->amOnPage('/form/select_multiple');
         $this->module->selectOption('What do you like the most?', ['eat', 'adult']);
@@ -387,7 +387,7 @@ public function testSelectMultipleOptionsByValue()
         $this->assertEquals(['eat', 'adult'], $form['like']);
     }
 
-    public function testHidden()
+    public function testHidden(): void
     {
         $this->module->amOnPage('/form/hidden');
         $this->module->click('Submit');
@@ -396,7 +396,7 @@ public function testHidden()
         $this->assertEquals('kill_people', $form['action']);
     }
 
-    public function testTextareaByCss()
+    public function testTextareaByCss(): void
     {
         $this->module->amOnPage('/form/textarea');
         $this->module->fillField('textarea', 'Nothing special');
@@ -406,7 +406,7 @@ public function testTextareaByCss()
         $this->assertEquals('Nothing special', $form['description']);
     }
 
-    public function testTextareaByLabel()
+    public function testTextareaByLabel(): void
     {
         $this->module->amOnPage('/form/textarea');
         $this->module->fillField('Description', 'Nothing special');
@@ -416,7 +416,7 @@ public function testTextareaByLabel()
         $this->assertEquals('Nothing special', $form['description']);
     }
 
-    public function testTextFieldByCss()
+    public function testTextFieldByCss(): void
     {
         $this->module->amOnPage('/form/field');
         $this->module->fillField('#name', 'Nothing special');
@@ -426,7 +426,7 @@ public function testTextFieldByCss()
         $this->assertEquals('Nothing special', $form['name']);
     }
 
-    public function testTextFieldByName()
+    public function testTextFieldByName(): void
     {
         $this->module->amOnPage('/form/example1');
         $this->module->fillField('LoginForm[username]', 'davert');
@@ -438,7 +438,7 @@ public function testTextFieldByName()
         $this->assertEquals('123456', $login['LoginForm']['password']);
     }
 
-    public function testTextFieldByLabel()
+    public function testTextFieldByLabel(): void
     {
         $this->module->amOnPage('/form/field');
         $this->module->fillField('Name', 'Nothing special');
@@ -448,7 +448,7 @@ public function testTextFieldByLabel()
         $this->assertEquals('Nothing special', $form['name']);
     }
 
-    public function testTextFieldByLabelWithoutFor()
+    public function testTextFieldByLabelWithoutFor(): void
     {
         $this->module->amOnPage('/form/field');
         $this->module->fillField('Other label', 'Nothing special');
@@ -458,7 +458,7 @@ public function testTextFieldByLabelWithoutFor()
         $this->assertEquals('Nothing special', $form['othername']);
     }
 
-    public function testFileFieldByCss()
+    public function testFileFieldByCss(): void
     {
         $this->module->amOnPage('/form/file');
         $this->module->attachFile('#avatar', 'app/avatar.jpg');
@@ -468,7 +468,7 @@ public function testFileFieldByCss()
         $this->assertArrayHasKey('avatar', $files);
     }
 
-    public function testFileFieldByLabel()
+    public function testFileFieldByLabel(): void
     {
         $this->module->amOnPage('/form/file');
         $this->module->attachFile('Avatar', 'app/avatar.jpg');
@@ -476,33 +476,33 @@ public function testFileFieldByLabel()
         $this->assertNotEmpty(data::get('files'));
     }
 
-    public function testSeeCheckboxIsNotChecked()
+    public function testSeeCheckboxIsNotChecked(): void
     {
         $this->module->amOnPage('/form/checkbox');
         $this->module->dontSeeCheckboxIsChecked('#checkin');
         $this->module->dontSeeCheckboxIsChecked('I Agree');
     }
 
-    public function testSeeCheckboxChecked()
+    public function testSeeCheckboxChecked(): void
     {
         $this->module->amOnPage('/info');
         $this->module->seeCheckboxIsChecked('input[type=checkbox]');
         $this->module->seeCheckboxIsChecked('Checked');
     }
 
-    public function testSeeWithNonLatin()
+    public function testSeeWithNonLatin(): void
     {
         $this->module->amOnPage('/info');
         $this->module->see('на');
     }
 
-    public function testSeeWithNonLatinAndSelectors()
+    public function testSeeWithNonLatinAndSelectors(): void
     {
         $this->module->amOnPage('/info');
         $this->module->see('Текст', 'p');
     }
 
-    public function testSeeInFieldOnInput()
+    public function testSeeInFieldOnInput(): void
     {
         $this->module->amOnPage('/form/field');
         $this->module->seeInField('Name', 'OLD_VALUE');
@@ -510,13 +510,13 @@ public function testSeeInFieldOnInput()
         $this->module->seeInField('descendant-or-self::input[@id="name"]', 'OLD_VALUE');
     }
 
-    public function testSeeInFieldForEmptyInput()
+    public function testSeeInFieldForEmptyInput(): void
     {
         $this->module->amOnPage('/form/empty');
         $this->module->seeInField('#empty_input', '');
     }
 
-    public function testSeeInFieldOnTextarea()
+    public function testSeeInFieldOnTextarea(): void
     {
         $this->module->amOnPage('/form/textarea');
         $this->module->seeInField('Description', 'sunrise');
@@ -524,13 +524,13 @@ public function testSeeInFieldOnTextarea()
         $this->module->seeInField('descendant-or-self::textarea[@id="description"]', 'sunrise');
     }
 
-    public function testSeeInFieldForEmptyTextarea()
+    public function testSeeInFieldForEmptyTextarea(): void
     {
         $this->module->amOnPage('/form/empty');
         $this->module->seeInField('#empty_textarea', '');
     }
 
-    public function testSeeInFieldOnCheckbox()
+    public function testSeeInFieldOnCheckbox(): void
     {
         $this->module->amOnPage('/form/field_values');
         $this->module->dontSeeInField('checkbox[]', 'not seen one');
@@ -541,7 +541,7 @@ public function testSeeInFieldOnCheckbox()
         $this->module->seeInField('checkbox[]', 'see test three');
     }
 
-    public function testSeeInFieldWithBoolean()
+    public function testSeeInFieldWithBoolean(): void
     {
         $this->module->amOnPage('/form/field_values');
         $this->module->seeInField('checkbox1', true);
@@ -554,7 +554,7 @@ public function testSeeInFieldWithBoolean()
         $this->module->dontSeeInField('radio3', true);
     }
 
-    public function testSeeInFieldOnRadio()
+    public function testSeeInFieldOnRadio(): void
     {
         $this->module->amOnPage('/form/field_values');
         $this->module->seeInField('radio1', 'see test one');
@@ -563,7 +563,7 @@ public function testSeeInFieldOnRadio()
         $this->module->dontSeeInField('radio1', 'not seen three');
     }
 
-    public function testSeeInFieldOnSelect()
+    public function testSeeInFieldOnSelect(): void
     {
         $this->module->amOnPage('/form/field_values');
         $this->module->seeInField('select1', 'see test one');
@@ -574,13 +574,13 @@ public function testSeeInFieldOnSelect()
         $this->module->dontSeeInField('select1', 'Not selected');
     }
 
-    public function testSeeInFieldEmptyValueForUnselectedSelect()
+    public function testSeeInFieldEmptyValueForUnselectedSelect(): void
     {
         $this->module->amOnPage('/form/field_values');
         $this->module->seeInField('select3', '');
     }
 
-    public function testSeeInFieldOnSelectMultiple()
+    public function testSeeInFieldOnSelectMultiple(): void
     {
         $this->module->amOnPage('/form/field_values');
         $this->module->dontSeeInField('select2', 'not seen one');
@@ -591,13 +591,13 @@ public function testSeeInFieldOnSelectMultiple()
         $this->module->seeInField('select2', 'see test three');
     }
 
-    public function testSeeInFieldWithExactMatch()
+    public function testSeeInFieldWithExactMatch(): void
     {
         $this->module->amOnPage('/form/field_values');
         $this->module->seeInField(['name' => 'select2'], 'see test one');
     }
 
-    public function testDontSeeInFieldOnInput()
+    public function testDontSeeInFieldOnInput(): void
     {
         $this->module->amOnPage('/form/field');
         $this->module->dontSeeInField('Name', 'Davert');
@@ -605,7 +605,7 @@ public function testDontSeeInFieldOnInput()
         $this->module->dontSeeInField('descendant-or-self::input[@id="name"]', 'Davert');
     }
 
-    public function testDontSeeInFieldOnTextarea()
+    public function testDontSeeInFieldOnTextarea(): void
     {
         $this->module->amOnPage('/form/textarea');
         $this->module->dontSeeInField('Description', 'sunset');
@@ -613,7 +613,7 @@ public function testDontSeeInFieldOnTextarea()
         $this->module->dontSeeInField('descendant-or-self::textarea[@id="description"]', 'sunset');
     }
 
-    public function testSeeInFormFields()
+    public function testSeeInFormFields(): void
     {
         $this->module->amOnPage('/form/field_values');
         $params = [
@@ -634,7 +634,7 @@ public function testSeeInFormFields()
         $this->module->seeInFormFields('form', $params);
     }
 
-    public function testSeeInFormFieldsFails()
+    public function testSeeInFormFieldsFails(): void
     {
         $this->module->amOnPage('/form/field_values');
         $this->expectException(AssertionFailedError::class);
@@ -652,7 +652,7 @@ public function testSeeInFormFieldsFails()
         $this->module->seeInFormFields('form', $params);
     }
 
-    public function testDontSeeInFormFields()
+    public function testDontSeeInFormFields(): void
     {
         $this->module->amOnPage('/form/field_values');
         $params = [
@@ -672,7 +672,7 @@ public function testDontSeeInFormFields()
         $this->module->dontSeeInFormFields('form', $params);
     }
 
-    public function testDontSeeInFormFieldsFails()
+    public function testDontSeeInFormFieldsFails(): void
     {
         $this->module->amOnPage('/form/field_values');
         $this->expectException(AssertionFailedError::class);
@@ -689,7 +689,7 @@ public function testDontSeeInFormFieldsFails()
         $this->module->dontSeeInFormFields('form', $params);
     }
 
-    public function testSeeInFormFieldsWithAssociativeArrays()
+    public function testSeeInFormFieldsWithAssociativeArrays(): void
     {
         $this->module->amOnPage('/form/example17');
         $this->module->seeInFormFields('form', [
@@ -698,20 +698,20 @@ public function testSeeInFormFieldsWithAssociativeArrays()
         ]);
     }
 
-    public function testSeeInFieldWithNonLatin()
+    public function testSeeInFieldWithNonLatin(): void
     {
         $this->module->amOnPage('/info');
         $this->module->seeInField('rus', 'Верно');
     }
 
-    public function testApostrophesInText()
+    public function testApostrophesInText(): void
     {
         $this->module->amOnPage('/info');
         $this->module->see("Don't do that at home!");
         $this->module->see("Don't do that at home!", 'h3');
     }
 
-    public function testSign()
+    public function testSign(): void
     {
         $this->module->amOnPage('/info');
         $this->module->seeLink('Sign in!');
@@ -719,7 +719,7 @@ public function testSign()
         $this->module->click('Sign in!');
     }
 
-    public function testGrabTextFrom()
+    public function testGrabTextFrom(): void
     {
         $this->module->amOnPage('/');
         $result = $this->module->grabTextFrom('h1');
@@ -730,7 +730,7 @@ public function testGrabTextFrom()
         $this->assertEquals('test', $result);
     }
 
-    public function testGrabValueFrom()
+    public function testGrabValueFrom(): void
     {
         $this->module->amOnPage('/form/hidden');
         $result = $this->module->grabValueFrom('#action');
@@ -748,7 +748,7 @@ public function testGrabValueFrom()
     /**
      * @see https://github.com/Codeception/Codeception/issues/3866
      */
-    public function testGrabValueFromWithFillField()
+    public function testGrabValueFromWithFillField(): void
     {
         $this->module->amOnPage('/form/bug3866');
         $this->module->fillField('empty', 'new value');
@@ -763,13 +763,13 @@ public function testGrabValueFromWithFillField()
         $this->assertEquals('new value', $result);
     }
 
-    public function testGrabAttributeFrom()
+    public function testGrabAttributeFrom(): void
     {
         $this->module->amOnPage('/search');
         $this->assertEquals('get', $this->module->grabAttributeFrom('form', 'method'));
     }
 
-    public function testLinksWithSimilarNames()
+    public function testLinksWithSimilarNames(): void
     {
         $this->module->amOnPage('/');
         $this->module->click('Test Link');
@@ -779,7 +779,7 @@ public function testLinksWithSimilarNames()
         $this->module->seeInCurrentUrl('/form/hidden');
     }
 
-    public function testLinksWithDifferentContext()
+    public function testLinksWithDifferentContext(): void
     {
         $this->module->amOnPage('/');
         $this->module->click('Test', '#area1');
@@ -789,7 +789,7 @@ public function testLinksWithDifferentContext()
         $this->module->seeInCurrentUrl('/form/hidden');
     }
 
-    public function testSeeElementOnPage()
+    public function testSeeElementOnPage(): void
     {
         $this->module->amOnPage('/form/field');
         $this->module->seeElement('input[name=name]');
@@ -802,14 +802,14 @@ public function testSeeElementOnPage()
     }
 
     // regression test. https://github.com/Codeception/Codeception/issues/587
-    public function testSeeElementOnPageFails()
+    public function testSeeElementOnPageFails(): void
     {
         $this->expectException(AssertionFailedError::class);
         $this->module->amOnPage('/form/field');
         $this->module->dontSeeElement('input[name=name]');
     }
 
-    public function testCookies()
+    public function testCookies(): void
     {
         $cookie_name = 'test_cookie';
         $cookie_value = 'this is a test';
@@ -828,7 +828,7 @@ public function testCookies()
         $this->module->dontSeeCookie($cookie_name);
     }
 
-    public function testCookiesWithPath()
+    public function testCookiesWithPath(): void
     {
         $cookie_name = 'cookie';
         $cookie_value = 'tasty';
@@ -846,7 +846,7 @@ public function testCookiesWithPath()
         $this->module->dontSeeCookie($cookie_name);
     }
 
-    public function testSendingCookies()
+    public function testSendingCookies(): void
     {
         $this->module->amOnPage('/');
         $this->module->setCookie('nocookie', '1111');
@@ -854,7 +854,7 @@ public function testSendingCookies()
         $this->module->see('nocookie', 'pre');
     }
 
-    public function testPageTitle()
+    public function testPageTitle(): void
     {
         $this->module->amOnPage('/');
         $this->module->seeInTitle('TestEd Beta 2.0');
@@ -864,77 +864,77 @@ public function testPageTitle()
         $this->module->dontSeeInTitle('TestEd Beta 2.0');
     }
 
-    public function testSeeFails()
+    public function testSeeFails(): void
     {
         $this->shouldFail();
         $this->module->amOnPage('/');
         $this->module->see('Text not here');
     }
 
-    public function testSeeInsideFails()
+    public function testSeeInsideFails(): void
     {
         $this->shouldFail();
         $this->module->amOnPage('/info');
         $this->module->see('woups', 'p');
     }
 
-    public function testDontSeeInInsideFails()
+    public function testDontSeeInInsideFails(): void
     {
         $this->shouldFail();
         $this->module->amOnPage('/info');
         $this->module->dontSee('interesting', 'p');
     }
 
-    public function testSeeElementFails()
+    public function testSeeElementFails(): void
     {
         $this->shouldFail();
         $this->module->amOnPage('/info');
         $this->module->seeElement('.alert');
     }
 
-    public function testDontSeeElementFails()
+    public function testDontSeeElementFails(): void
     {
         $this->shouldFail();
         $this->module->amOnPage('/info');
         $this->module->dontSeeElement('#back');
     }
 
-    public function testSeeInFieldFail()
+    public function testSeeInFieldFail(): void
     {
         $this->shouldFail();
         $this->module->amOnPage('/form/empty');
         $this->module->seeInField('#empty_textarea', 'xxx');
     }
 
-    public function testSeeInFieldOnTextareaFails()
+    public function testSeeInFieldOnTextareaFails(): void
     {
         $this->shouldFail();
         $this->module->amOnPage('/form/textarea');
         $this->module->dontSeeInField('Description', 'sunrise');
     }
 
-    public function testSeeCheckboxIsNotCheckedFails()
+    public function testSeeCheckboxIsNotCheckedFails(): void
     {
         $this->shouldFail();
         $this->module->amOnPage('/form/complex');
         $this->module->dontSeeCheckboxIsChecked('#checkin');
     }
 
-    public function testSeeCheckboxCheckedFails()
+    public function testSeeCheckboxCheckedFails(): void
     {
         $this->shouldFail();
         $this->module->amOnPage('/form/checkbox');
         $this->module->seeCheckboxIsChecked('#checkin');
     }
 
-    public function testDontSeeElementOnPageFails()
+    public function testDontSeeElementOnPageFails(): void
     {
         $this->shouldFail();
         $this->module->amOnPage('/form/field');
         $this->module->dontSeeElement('descendant-or-self::input[@id="name"]');
     }
 
-    public function testStrictLocators()
+    public function testStrictLocators(): void
     {
         $this->module->amOnPage('/login');
         $this->module->seeElement(['id' => 'submit-label']);
@@ -953,14 +953,14 @@ public function testStrictLocators()
         $this->module->seeCurrentUrlEquals('/form/hidden');
     }
 
-    public function testFailStrictLocators()
+    public function testFailStrictLocators(): void
     {
         $this->shouldFail();
         $this->module->amOnPage('/form/checkbox');
         $this->module->checkOption(['name' => 'age']);
     }
 
-    public function testExample1()
+    public function testExample1(): void
     {
         $this->module->amOnPage('/form/example1');
         $this->module->see('Login', 'button');
@@ -975,7 +975,7 @@ public function testExample1()
         $this->assertNotEmpty($login['LoginForm']['rememberMe']);
     }
 
-    public function testExample2()
+    public function testExample2(): void
     {
         $this->module->amOnPage('/form/example2');
         $this->module->fillField('input[name=username]', 'davert');
@@ -988,7 +988,7 @@ public function testExample2()
         $this->assertEquals('login', $login['action']);
     }
 
-    public function testAmpersand()
+    public function testAmpersand(): void
     {
         $this->module->amOnPage('/info');
         $this->module->see('Kill & Destroy');
@@ -998,7 +998,7 @@ public function testAmpersand()
     /**
      * https://github.com/Codeception/Codeception/issues/1091
      */
-    public function testExample4()
+    public function testExample4(): void
     {
         $this->module->amOnPage('/form/example4');
         $this->module->click(['css' => '#register button[type="submit"]']);
@@ -1010,7 +1010,7 @@ public function testExample4()
     /**
      * https://github.com/Codeception/Codeception/issues/1098
      */
-    public function testExample5()
+    public function testExample5(): void
     {
         $this->module->amOnPage('/form/example5');
         $this->module->fillField('username', 'John');
@@ -1019,14 +1019,14 @@ public function testExample5()
         $this->module->seeCurrentUrlEquals('/form/example5?username=John&password=1234');
     }
 
-    public function testExample5WithSubmitForm()
+    public function testExample5WithSubmitForm(): void
     {
         $this->module->amOnPage('/form/example5');
         $this->module->submitForm('form', ['username' => 'John', 'password' => '1234']);
         $this->module->seeCurrentUrlEquals('/form/example5?username=John&password=1234');
     }
 
-    public function testExample5WithParams()
+    public function testExample5WithParams(): void
     {
         $this->module->amOnPage('/form/example5?a=b');
         $this->module->fillField('username', 'John');
@@ -1035,7 +1035,7 @@ public function testExample5WithParams()
         $this->module->seeCurrentUrlEquals('/form/example5?username=John&password=1234');
     }
 
-    public function testExample5WithSubmitFormAndParams()
+    public function testExample5WithSubmitFormAndParams(): void
     {
         $this->module->amOnPage('/form/example5?a=b');
         $this->module->submitForm('form', ['username' => 'John', 'password' => '1234']);
@@ -1045,7 +1045,7 @@ public function testExample5WithSubmitFormAndParams()
     /**
      * @Issue https://github.com/Codeception/Codeception/issues/1212
      */
-    public function testExample9()
+    public function testExample9(): void
     {
         $this->module->amOnPage('/form/example9');
         $this->module->attachFile('form[name=package_csv_form] input[name=xls_file]', 'app/avatar.jpg');
@@ -1060,7 +1060,7 @@ public function testExample9()
         $this->assertArrayHasKey('form_name', $form);
     }
 
-    public function testSubmitForm()
+    public function testSubmitForm(): void
     {
         $this->module->amOnPage('/form/complex');
         $this->module->submitForm('form', [
@@ -1077,7 +1077,7 @@ public function testSubmitForm()
         $this->assertEquals('kill_all', $form['action']);
     }
 
-    public function testSubmitFormWithFillField()
+    public function testSubmitFormWithFillField(): void
     {
         $this->module->amOnPage('/form/complex');
         $this->module->fillField('name', 'Kilgore Trout');
@@ -1090,7 +1090,7 @@ public function testSubmitFormWithFillField()
         $this->assertEquals('Is from Iliyum, NY', $form['description']);
     }
 
-    public function testSubmitFormWithoutButton()
+    public function testSubmitFormWithoutButton(): void
     {
         $this->module->amOnPage('/form/empty');
         $this->module->submitForm('form', [
@@ -1100,7 +1100,7 @@ public function testSubmitFormWithoutButton()
         $this->assertEquals('Hello!', $form['text']);
     }
 
-    public function testSubmitFormWithAmpersand()
+    public function testSubmitFormWithAmpersand(): void
     {
         $this->module->amOnPage('/form/submitform_ampersands');
         $this->module->submitForm('form', []);
@@ -1109,7 +1109,7 @@ public function testSubmitFormWithAmpersand()
         $this->assertEquals('this & that', $form['test']);
     }
 
-    public function testSubmitFormWithArrayField()
+    public function testSubmitFormWithArrayField(): void
     {
         $this->module->amOnPage('/form/example17');
         $this->module->submitForm('form', []);
@@ -1119,7 +1119,7 @@ public function testSubmitFormWithArrayField()
         $this->assertArrayNotHasKey('FooBar[bar]', $data);
     }
 
-    public function testSubmitFormMultiSelectWithArrayParameter()
+    public function testSubmitFormMultiSelectWithArrayParameter(): void
     {
         $this->module->amOnPage('/form/submitform_multiple');
         $this->module->submitForm('form', [
@@ -1134,7 +1134,7 @@ public function testSubmitFormMultiSelectWithArrayParameter()
         $this->assertEquals('not seen four', $form['select'][1]);
     }
 
-    public function testSubmitFormWithMultiSelect()
+    public function testSubmitFormWithMultiSelect(): void
     {
         $this->module->amOnPage('/form/submitform_multiple');
         $this->module->submitForm('form', []);
@@ -1145,7 +1145,7 @@ public function testSubmitFormWithMultiSelect()
         $this->assertEquals('see test two', $form['select'][1]);
     }
 
-    public function testSubmitFormCheckboxWithArrayParameter()
+    public function testSubmitFormCheckboxWithArrayParameter(): void
     {
         $this->module->amOnPage('/form/field_values');
         $this->module->submitForm('form', [
@@ -1162,7 +1162,7 @@ public function testSubmitFormCheckboxWithArrayParameter()
         $this->assertEquals('not seen three', $form['checkbox'][2]);
     }
 
-    public function testSubmitFormCheckboxWithBooleanArrayParameter()
+    public function testSubmitFormCheckboxWithBooleanArrayParameter(): void
     {
         $this->module->amOnPage('/form/field_values');
         $this->module->submitForm('form', [
@@ -1181,13 +1181,13 @@ public function testSubmitFormCheckboxWithBooleanArrayParameter()
     /**
      * https://github.com/Codeception/Codeception/issues/1381
      */
-    public function testFillingFormFieldWithoutSubmitButton()
+    public function testFillingFormFieldWithoutSubmitButton(): void
     {
         $this->module->amOnPage('/form/empty_fill');
         $this->module->fillField('test', 'value');
     }
 
-    public function testSubmitFormWithDefaultTextareaValue()
+    public function testSubmitFormWithDefaultTextareaValue(): void
     {
         $this->module->amOnPage('/form/textarea');
         $this->module->submitForm('form', []);
@@ -1199,7 +1199,7 @@ public function testSubmitFormWithDefaultTextareaValue()
     /**
      * @issue #1180
      */
-    public function testClickLinkWithInnerSpan()
+    public function testClickLinkWithInnerSpan(): void
     {
         $this->module->amOnPage('/form/example7');
         $this->module->click("Buy Chocolate Bar");
@@ -1209,7 +1209,7 @@ public function testClickLinkWithInnerSpan()
     /*
      * @issue #1304
      */
-    public function testSelectTwoSubmitsByText()
+    public function testSelectTwoSubmitsByText(): void
     {
         $this->module->amOnPage('/form/select_two_submits');
         $this->module->selectOption('What kind of sandwich would you like?', '2');
@@ -1219,7 +1219,7 @@ public function testSelectTwoSubmitsByText()
         $this->assertEquals(2, $form['sandwich_select']);
     }
 
-    public function testSelectTwoSubmitsByCSS()
+    public function testSelectTwoSubmitsByCSS(): void
     {
         $this->module->amOnPage('/form/select_two_submits');
         $this->module->selectOption("form select[name='sandwich_select']", '2');
@@ -1237,7 +1237,7 @@ protected function shouldFail()
     /**
      * https://github.com/Codeception/Codeception/issues/1051
      */
-    public function testSubmitFormWithTwoSubmitButtonsSubmitsCorrectValue()
+    public function testSubmitFormWithTwoSubmitButtonsSubmitsCorrectValue(): void
     {
         $this->module->amOnPage('/form/example10');
         $this->module->seeElement("#button2");
@@ -1253,7 +1253,7 @@ public function testSubmitFormWithTwoSubmitButtonsSubmitsCorrectValue()
     /**
      * https://github.com/Codeception/Codeception/issues/1051
      */
-    public function testSubmitFormWithTwoSubmitButtonsSubmitsCorrectValueAfterFillField()
+    public function testSubmitFormWithTwoSubmitButtonsSubmitsCorrectValueAfterFillField(): void
     {
         $this->module->amOnPage('/form/example10');
         $this->module->fillField("username", "bob");
@@ -1269,7 +1269,7 @@ public function testSubmitFormWithTwoSubmitButtonsSubmitsCorrectValueAfterFillFi
     /*
      * https://github.com/Codeception/Codeception/issues/1274
      */
-    public function testSubmitFormWithDocRelativePathForAction()
+    public function testSubmitFormWithDocRelativePathForAction(): void
     {
         $this->module->amOnPage('/form/example12');
         $this->module->submitForm('form', [
@@ -1278,7 +1278,7 @@ public function testSubmitFormWithDocRelativePathForAction()
         $this->module->seeCurrentUrlEquals('/form/example11');
     }
 
-    public function testSubmitFormWithDocRelativePathForActionFromDefaultPage()
+    public function testSubmitFormWithDocRelativePathForActionFromDefaultPage(): void
     {
         $this->module->amOnPage('/form/');
         $this->module->submitForm('form', [
@@ -1287,7 +1287,7 @@ public function testSubmitFormWithDocRelativePathForActionFromDefaultPage()
         $this->module->seeCurrentUrlEquals('/form/example11');
     }
 
-    public function testLinkWithDocRelativeURLFromDefaultPage()
+    public function testLinkWithDocRelativeURLFromDefaultPage(): void
     {
         $this->module->amOnPage('/form/');
         $this->module->click('Doc-Relative Link');
@@ -1297,7 +1297,7 @@ public function testLinkWithDocRelativeURLFromDefaultPage()
     /*
      * https://github.com/Codeception/Codeception/issues/1507
      */
-    public function testSubmitFormWithDefaultRadioAndCheckboxValues()
+    public function testSubmitFormWithDefaultRadioAndCheckboxValues(): void
     {
         $this->module->amOnPage('/form/example16');
         $this->module->submitForm('form', [
@@ -1310,7 +1310,7 @@ public function testSubmitFormWithDefaultRadioAndCheckboxValues()
         $this->assertEquals('to be sent', $form['radio1']);
     }
 
-    public function testSubmitFormCheckboxWithBoolean()
+    public function testSubmitFormCheckboxWithBoolean(): void
     {
         $this->module->amOnPage('/form/example16');
         $this->module->submitForm('form', [
@@ -1328,14 +1328,14 @@ public function testSubmitFormCheckboxWithBoolean()
         $this->assertArrayNotHasKey('checkbox1', $form, 'Checkbox value sent');
     }
 
-    public function testSubmitFormWithCheckboxesWithoutValue()
+    public function testSubmitFormWithCheckboxesWithoutValue(): void
     {
         $this->module->amOnPage('/form/checkbox_default_value');
         $this->module->submitForm('form', ['checkbox1' => true]);
         $this->assertSame('on', data::get('query')['checkbox1']);
     }
 
-    public function testSubmitFormWithButtons()
+    public function testSubmitFormWithButtons(): void
     {
         $this->module->amOnPage('/form/form_with_buttons');
         $this->module->submitForm('form', [
@@ -1375,35 +1375,35 @@ public function testSubmitFormWithButtons()
     /**
      * https://github.com/Codeception/Codeception/issues/1409
      */
-    public function testWrongXpath()
+    public function testWrongXpath(): void
     {
         $this->expectException(MalformedLocatorException::class);
         $this->module->amOnPage('/');
         $this->module->seeElement('//aas[asd}[sd]a[/[');
     }
 
-    public function testWrongCSS()
+    public function testWrongCSS(): void
     {
         $this->expectException(MalformedLocatorException::class);
         $this->module->amOnPage('/');
         $this->module->seeElement('.user#iasos<here');
     }
 
-    public function testWrongStrictCSSLocator()
+    public function testWrongStrictCSSLocator(): void
     {
         $this->expectException(MalformedLocatorException::class);
         $this->module->amOnPage('/');
         $this->module->seeElement(['css' => 'hel!1$<world']);
     }
 
-    public function testWrongStrictXPathLocator()
+    public function testWrongStrictXPathLocator(): void
     {
         $this->expectException(MalformedLocatorException::class);
         $this->module->amOnPage('/');
         $this->module->seeElement(['xpath' => 'hello<wo>rld']);
     }
 
-    public function testFormWithFilesArray()
+    public function testFormWithFilesArray(): void
     {
         $this->module->amOnPage('/form/example13');
         $this->module->attachFile('foo[bar]', 'app/avatar.jpg');
@@ -1415,7 +1415,7 @@ public function testFormWithFilesArray()
         $this->assertArrayHasKey('baz', $files['foo']['name']);
     }
 
-    public function testFormWithFileSpecialCharNames()
+    public function testFormWithFileSpecialCharNames(): void
     {
         $this->module->amOnPage('/form/example14');
         $this->module->attachFile('foo bar', 'app/avatar.jpg');
@@ -1431,7 +1431,7 @@ public function testFormWithFileSpecialCharNames()
     /**
      * @Issue https://github.com/Codeception/Codeception/issues/1454
      */
-    public function testTextFieldByNameFirstNotCss()
+    public function testTextFieldByNameFirstNotCss(): void
     {
         $this->module->amOnPage('/form/example15');
         $this->module->fillField('title', 'Special Widget');
@@ -1446,7 +1446,7 @@ public function testTextFieldByNameFirstNotCss()
     /**
      * @Issue https://github.com/Codeception/Codeception/issues/1535
      */
-    public function testCheckingOptionsWithComplexNames()
+    public function testCheckingOptionsWithComplexNames(): void
     {
         $this->module->amOnPage('/form/bug1535');
         $this->module->checkOption('#bmessage-topicslinks input[value="4"]');
@@ -1460,7 +1460,7 @@ public function testCheckingOptionsWithComplexNames()
      * @Issue https://github.com/Codeception/Codeception/issues/1585
      * @Issue https://github.com/Codeception/Codeception/issues/1602
      */
-    public function testUnreachableField()
+    public function testUnreachableField(): void
     {
         $this->module->amOnPage('/form/bug1585');
         $this->module->fillField('textarea[name="captions[]"]', 'test2');
@@ -1475,7 +1475,7 @@ public function testUnreachableField()
         $this->assertContains('davert', $data['users']);
     }
 
-    public function testSubmitAdjacentForms()
+    public function testSubmitAdjacentForms(): void
     {
         $this->module->amOnPage('/form/submit_adjacentforms');
         $this->module->submitForm('#form-2', []);
@@ -1486,7 +1486,7 @@ public function testSubmitAdjacentForms()
         $this->assertEquals('Killgore Trout', $data['second-field']);
     }
 
-    public function testSubmitAdjacentFormsByButton()
+    public function testSubmitAdjacentFormsByButton(): void
     {
         $this->module->amOnPage('/form/submit_adjacentforms');
         $this->module->fillField('first-field', 'First');
@@ -1509,14 +1509,14 @@ public function testSubmitAdjacentFormsByButton()
         $this->assertEquals('Second', $data['second-field']);
     }
 
-    public function testArrayField()
+    public function testArrayField(): void
     {
         $this->module->amOnPage('/form/example17');
         $this->module->seeInField('input[name="FooBar[bar]"]', 'baz');
         $this->module->seeInField('input[name="Food[beer][yum][yeah]"]', 'mmhm');
     }
 
-    public function testFillFieldSquareBracketNames()
+    public function testFillFieldSquareBracketNames(): void
     {
         $this->module->amOnPage('/form/names-sq-brackets');
         $this->module->fillField('//input[@name="input_text"]', 'filling this input');
@@ -1531,7 +1531,7 @@ public function testFillFieldSquareBracketNames()
         $this->module->fillField('//textarea[@name="textarea[name][]"]', 'filling this textarea most');
     }
 
-    public function testSelectAndCheckOptionSquareBracketNames()
+    public function testSelectAndCheckOptionSquareBracketNames(): void
     {
         $this->module->amOnPage('/form/names-sq-brackets');
         $this->module->selectOption('//input[@name="input_radio_name"]', '1');
@@ -1553,7 +1553,7 @@ public function testSelectAndCheckOptionSquareBracketNames()
         $this->module->selectOption('//select[@name="select[name][]"]', '1');
     }
 
-    public function testFillFieldWithAmpersand()
+    public function testFillFieldWithAmpersand(): void
     {
         $this->module->amOnPage('/form/field');
         $this->module->fillField('Name', 'this & that');
@@ -1563,35 +1563,35 @@ public function testFillFieldWithAmpersand()
         $this->assertEquals('this & that', $form['name']);
     }
 
-    public function testSeeInDeactivatedField()
+    public function testSeeInDeactivatedField(): void
     {
         $this->module->amOnPage('/form/complex');
         $this->module->seeInField('#disabled_field', 'disabled_field');
         $this->module->seeInField('#salutation', 'mr');
     }
 
-    public function testSwitchToIframe()
+    public function testSwitchToIframe(): void
     {
         $this->module->amOnPage('/iframe');
         $this->module->switchToIframe('content');
         $this->module->see('Is that interesting?');
         $this->module->click('Ссылочка');
     }
-    
-    public function testGrabMultiple()
+
+    public function testGrabMultiple(): void
     {
         $this->module->amOnPage('/info');
-        
+
         $arr = $this->module->grabMultiple('#grab-multiple a:first-child');
         $this->assertCount(1, $arr);
         $this->assertEquals('First', $arr[0]);
-        
+
         $arr = $this->module->grabMultiple('#grab-multiple a');
         $this->assertCount(3, $arr);
         $this->assertEquals('First', $arr[0]);
         $this->assertEquals('Second', $arr[1]);
         $this->assertEquals('Third', $arr[2]);
-        
+
         // href for WebDriver with selenium returns a full link, so testing with ID
         $arr = $this->module->grabMultiple('#grab-multiple a', 'id');
         $this->assertCount(3, $arr);
@@ -1603,7 +1603,7 @@ public function testGrabMultiple()
     /**
      * @issue https://github.com/Codeception/Codeception/issues/2960
      */
-    public function testClickMultiByteLink()
+    public function testClickMultiByteLink(): void
     {
         $this->module->amOnPage('/info');
         $this->module->click('Franšízy - pobočky');
@@ -1613,7 +1613,7 @@ public function testClickMultiByteLink()
     /**
      * @issue https://github.com/Codeception/Codeception/issues/3528
      */
-    public function testClickThrowsElementNotFoundExceptionWhenTextContainsNumber()
+    public function testClickThrowsElementNotFoundExceptionWhenTextContainsNumber(): void
     {
         $this->expectException(ElementNotFound::class);
         $this->expectExceptionMessage("'Link 2' is invalid CSS and XPath selector and Link or Button element with 'name=Link 2' was not found.");
@@ -1621,14 +1621,14 @@ public function testClickThrowsElementNotFoundExceptionWhenTextContainsNumber()
         $this->module->click('Link 2');
     }
 
-    public function testClickExistingLinkWithTextContainingNumber()
+    public function testClickExistingLinkWithTextContainingNumber(): void
     {
         $this->module->amOnPage('/info');
         $this->module->click('Link 3');
         $this->module->seeCurrentUrlEquals('/cookies');
     }
 
-    public function testSelectOptionValueSelector()
+    public function testSelectOptionValueSelector(): void
     {
         $this->module->amOnPage('/form/select_selectors');
         $this->module->selectOption('age', ['value' => '20']);
@@ -1638,7 +1638,7 @@ public function testSelectOptionValueSelector()
         $this->assertEquals('20', $data['age']);
     }
 
-    public function testSelectOptionTextSelector()
+    public function testSelectOptionTextSelector(): void
     {
         $this->module->amOnPage('/form/select_selectors');
 
@@ -1649,77 +1649,77 @@ public function testSelectOptionTextSelector()
         $this->module->seeOptionIsSelected('age', '21');
     }
 
-    public function testClickButtonInLink()
+    public function testClickButtonInLink(): void
     {
         $this->module->amOnPage('/form/button_in_link');
         $this->module->click('More Info');
         $this->module->seeCurrentUrlEquals('/info');
     }
 
-    public function testClickButtonInLinkAndSpan()
+    public function testClickButtonInLinkAndSpan(): void
     {
         $this->module->amOnPage('/form/button_in_link');
         $this->module->click('Span Info');
         $this->module->seeCurrentUrlEquals('/info');
     }
 
-    public function testClickButtonInLinkUsingCssLocator()
+    public function testClickButtonInLinkUsingCssLocator(): void
     {
         $this->module->amOnPage('/form/button_in_link');
         $this->module->click(['css' => 'input[value="More Info"]']);
         $this->module->seeCurrentUrlEquals('/info');
     }
 
-    public function testClickButtonInLinkAndSpanUsingCssLocator()
+    public function testClickButtonInLinkAndSpanUsingCssLocator(): void
     {
         $this->module->amOnPage('/form/button_in_link');
         $this->module->click(['css' => 'input[value="Span Info"]']);
         $this->module->seeCurrentUrlEquals('/info');
     }
 
-    public function testClickHashLink()
+    public function testClickHashLink(): void
     {
         $this->module->amOnPage('/form/anchor');
         $this->module->click('Hash Link');
         $this->module->seeCurrentUrlEquals('/form/anchor');
     }
 
-    public function testClickHashButton()
+    public function testClickHashButton(): void
     {
         $this->module->amOnPage('/form/anchor');
         $this->module->click('Hash Button');
         $this->module->seeCurrentUrlEquals('/form/anchor');
     }
 
-    public function testSubmitHashForm()
+    public function testSubmitHashForm(): void
     {
         $this->module->amOnPage('/form/anchor');
         $this->module->click('Hash Form');
         $this->module->seeCurrentUrlEquals('/form/anchor');
     }
 
-    public function testClickingRelativeLinkHonoursBaseHref()
+    public function testClickingRelativeLinkHonoursBaseHref(): void
     {
         $this->module->amOnPage('/basehref');
         $this->module->click('Relative Link');
         $this->module->seeCurrentUrlEquals('/form/example7');
     }
 
-    public function testSubmittingRelativeFormHonoursBaseHref()
+    public function testSubmittingRelativeFormHonoursBaseHref(): void
     {
         $this->module->amOnPage('/basehref');
         $this->module->click('Relative Form');
         $this->module->seeCurrentUrlEquals('/form/example5');
     }
 
-    public function testClickingRelativeLinkInContextHonoursBaseHref()
+    public function testClickingRelativeLinkInContextHonoursBaseHref(): void
     {
         $this->module->amOnPage('/basehref');
         $this->module->click('Relative Link', 'p');
         $this->module->seeCurrentUrlEquals('/form/example7');
     }
 
-    public function testSubmittingRelativeForminContextHonoursBaseHref()
+    public function testSubmittingRelativeForminContextHonoursBaseHref(): void
     {
         $this->module->amOnPage('/basehref');
         $this->module->fillField('rus', 'test value');
@@ -1727,14 +1727,14 @@ public function testSubmittingRelativeForminContextHonoursBaseHref()
         $this->module->seeCurrentUrlEquals('/form/example5');
     }
 
-    public function testClickingFormButtonInContextSubmitsOutOfContextFormElements()
+    public function testClickingFormButtonInContextSubmitsOutOfContextFormElements(): void
     {
         $this->module->amOnPage('/basehref');
         $this->module->click('Relative Form', '#button-container');
         $this->assertArrayHasKey('rus', data::get('form'));
     }
 
-    public function testAttachFileThrowsCorrectMessageWhenFileDoesNotExist()
+    public function testAttachFileThrowsCorrectMessageWhenFileDoesNotExist(): void
     {
         $filename = 'does-not-exist.jpg';
         $expectedMessage = 'File does not exist: ' . codecept_data_dir($filename);
@@ -1745,7 +1745,7 @@ public function testAttachFileThrowsCorrectMessageWhenFileDoesNotExist()
         $this->module->attachFile('Avatar', $filename);
     }
 
-    public function testPasswordArgument()
+    public function testPasswordArgument(): void
     {
         $this->module->amOnPage('/form/password_argument');
         $this->module->fillField('password', new PasswordArgument('thisissecret'));