diff --git a/.editorconfig b/.editorconfig
new file mode 100644
index 0000000..5599209
--- /dev/null
+++ b/.editorconfig
@@ -0,0 +1,17 @@
+# Editor configuration normalization
+# @see http://editorconfig.org/
+
+# This is the top-most .editorconfig file; do not search in parent directories.
+root = true
+
+# All files.
+[*]
+end_of_line = LF
+indent_style = space
+indent_size = 4
+charset = utf-8
+trim_trailing_whitespace = true
+insert_final_newline = true
+
+[{*.yml,*yaml}]
+indent_size = 2
diff --git a/.gitignore b/.gitignore
index e26f45e..f8d51f0 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,5 @@
 composer.phar
 /vendor/
 composer.lock
+.bash_history
+/.phpunit.result.cache
diff --git a/.lando.env b/.lando.env
new file mode 100644
index 0000000..36dddbc
--- /dev/null
+++ b/.lando.env
@@ -0,0 +1,10 @@
+# Lando specific - uses user home directory to store Composer cache and other stuff
+# Helps to re-use Composer cache between projects.
+COMPOSER_HOME=/user/.composer
+# https://xdebug.org/docs/step_debug
+# https://xdebug.org/docs/step_debug#client_host
+# https://docs.lando.dev/config/php.html#configuration
+PHP_IDE_CONFIG=serverName=drupalauth.lndo.site
+# Ignore commands starting with space and duplicates.
+HISTCONTROL=ignoreboth
+HOME=/app
diff --git a/.lando.yml b/.lando.yml
new file mode 100644
index 0000000..655c9e0
--- /dev/null
+++ b/.lando.yml
@@ -0,0 +1,53 @@
+name: drupalauth
+
+services:
+  php80:
+    type: php:8.0
+    via: cli
+    xdebug: "off"
+    composer_version: 2
+  php81:
+    type: php:8.1
+    via: cli
+    xdebug: "off"
+    composer_version: 2
+  php82:
+    type: php:8.2
+    via: cli
+    xdebug: "off"
+    composer_version: 2
+
+
+
+
+env_file:
+  - .lando.env
+
+tooling:
+  style-lint:
+    cmd: ./scripts/style-lint.sh
+    service: :service
+    options:
+      service:
+        default: php80
+        describe: Run phpcs in different service
+        alias:
+          - s
+  style-fix:
+    cmd: ./scripts/style-fix.sh
+    service: :service
+    options:
+      service:
+        default: php80
+        describe: Run phpcs in different service
+        alias:
+          - s
+  phpunit:
+    cmd: ./scripts/phpunit.sh
+    service: :service
+    options:
+      service:
+        default: php80
+        describe: Run phpunit in different service
+        alias:
+          - s
diff --git a/.travis.yml b/.travis.yml
index 3549c0b..e89dadf 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,10 +1,13 @@
+os: linux
 language: php
-php:
-   - '7.1'
-   - '7.2'
-   - '7.3'
-   - '7.4'
-   - '8.0'
+jobs:
+  include:
+    - php: '8.0'
+      dist: focal
+    - php: '8.1'
+      dist: jammy
+    - php: '8.2'
+      dist: jammy
 
 before_script: composer install
 script:
diff --git a/composer.json b/composer.json
index 6d4d588..95b3153 100644
--- a/composer.json
+++ b/composer.json
@@ -21,16 +21,16 @@
     }
   ],
   "require": {
-    "php": "^5.6.0|^7.0|^8.0",
-    "simplesamlphp/simplesamlphp": "~2.0",
+    "php": "^8.0",
+    "simplesamlphp/simplesamlphp": "^2.1",
     "simplesamlphp/composer-module-installer": "~1.0"
   },
   "require-dev": {
-    "phpunit/phpunit": "^5|^6|^7|^8|^9",
-    "squizlabs/php_codesniffer": "^2.0.0|^3.0.0"
+    "phpunit/phpunit": "^9.0 | ^10.0",
+    "squizlabs/php_codesniffer": "^3.0"
   },
   "autoload-dev": {
-    "classmap": ["lib/", "tests/lib/"]
+    "classmap": ["src/", "tests/"]
   },
   "extra": {
     "branch-alias": {
diff --git a/default-enable b/default-enable
deleted file mode 100644
index 25615cb..0000000
--- a/default-enable
+++ /dev/null
@@ -1,3 +0,0 @@
-This file indicates that the default state of this module
-is enabled. To disable, create a file named disable in the
-same directory as this file.
diff --git a/lib/ConfigHelper.php b/lib/ConfigHelper.php
deleted file mode 100644
index d67650f..0000000
--- a/lib/ConfigHelper.php
+++ /dev/null
@@ -1,126 +0,0 @@
-<?php
-
-namespace SimpleSAML\Module\drupalauth;
-
-use SimpleSAML\Configuration;
-use SimpleSAML\Utils\Config;
-
-/**
- * Drupal authentication source configuration parser.
- */
-class ConfigHelper
-{
-
-
-    /**
-     * String with the location of this configuration.
-     * Used for error reporting.
-     */
-    private $location;
-
-
-    /**
-     * The filesystem path to the Drupal directory
-     */
-    private $drupalroot;
-
-
-    /**
-     * Whether debug output is enabled.
-     *
-     * @var bool
-     */
-    private $debug;
-
-
-  /**
-   * The attributes we should fetch. Can be NULL in which case we will fetch all attributes.
-   */
-    private $attributes;
-
-
-    /**
-   * The Drupal logout URL
-   */
-    private $drupal_logout_url;
-
-
-  /**
-   * The Drupal login URL
-   */
-    private $drupal_login_url;
-
-
-    /**
-     * Constructor for this configuration parser.
-     *
-     * @param array $config  Configuration.
-     * @param string $location  The location of this configuration. Used for error reporting.
-     */
-    public function __construct($config, $location) {
-      assert(is_array($config));
-      assert(is_string($location));
-
-      $this->location = $location;
-
-      /* Get authsource configuration. */
-      $config = Configuration::loadFromArray($config, $location);
-
-      $this->drupalroot = $config->getString('drupalroot');
-      $this->debug = $config->getBoolean('debug', FALSE);
-      $this->attributes = $config->getArray('attributes', []);
-      $this->drupal_logout_url = $config->getString('drupal_logout_url', NULL);
-      $this->drupal_login_url = $config->getString('drupal_login_url', NULL);
-    }
-
-    /**
-     * Returns debug mode.
-     *
-     * @return boolean
-     */
-    public function getDebug()
-    {
-        return $this->debug;
-    }
-
-    /**
-     * Returns Drupal root directory.
-     *
-     * @return string
-     */
-    public function getDrupalroot()
-    {
-        return $this->drupalroot;
-    }
-
-  /**
-   * Return the attributes
-   *
-   * @return array
-   */
-    public function getAttributes()
-    {
-        return $this->attributes;
-    }
-
-
-    /**
-     * Returns Drupal logout URL.
-     *
-     * @return string
-   */
-    public function getDrupalLogoutURL()
-    {
-        return $this->drupal_logout_url;
-    }
-
-  /**
-   * Returns Drupal login URL.
-   *
-   * @return string
-   */
-    public function getDrupalLoginURL()
-    {
-        return $this->drupal_login_url;
-    }
-}
diff --git a/phpcs.xml b/phpcs.xml
index b0ede41..bd16e4e 100644
--- a/phpcs.xml
+++ b/phpcs.xml
@@ -2,7 +2,7 @@
 <ruleset name="drupalauth">
     <description>The coding standard for drupalauth.</description>
 
-    <rule ref="PSR2" />
-    <file>./lib</file>
-    <file>./www</file>
+    <rule ref="PSR12" />
+    <file>./src</file>
+    <file>./public</file>
 </ruleset>
diff --git a/www/resume.php b/public/resume.php
similarity index 100%
rename from www/resume.php
rename to public/resume.php
diff --git a/scripts/phpunit.sh b/scripts/phpunit.sh
new file mode 100755
index 0000000..4d300d5
--- /dev/null
+++ b/scripts/phpunit.sh
@@ -0,0 +1,7 @@
+#!/usr/bin/env bash
+
+php -v
+rm -rf ./vendor composer.lock
+composer install
+
+./vendor/bin/phpunit
diff --git a/scripts/style-fix.sh b/scripts/style-fix.sh
new file mode 100755
index 0000000..133e82c
--- /dev/null
+++ b/scripts/style-fix.sh
@@ -0,0 +1,6 @@
+#!/usr/bin/env bash
+
+rm -rf ./vendor composer.lock
+composer install
+
+./vendor/bin/phpcbf
diff --git a/scripts/style-lint.sh b/scripts/style-lint.sh
new file mode 100755
index 0000000..af2acab
--- /dev/null
+++ b/scripts/style-lint.sh
@@ -0,0 +1,13 @@
+#!/usr/bin/env bash
+
+rm -rf ./vendor composer.lock
+composer install
+
+./vendor/bin/phpcs
+
+#lando phpunit -s php80
+#lando style-lint -s php80
+#lando phpunit -s php81
+#lando style-lint -s php81
+#lando phpunit -s php82
+#lando style-lint -s php82
diff --git a/lib/Auth/Source/External.php b/src/Auth/Source/External.php
similarity index 83%
rename from lib/Auth/Source/External.php
rename to src/Auth/Source/External.php
index b335105..bdaf802 100755
--- a/lib/Auth/Source/External.php
+++ b/src/Auth/Source/External.php
@@ -74,28 +74,27 @@
  */
 class External extends Source
 {
+    /**
+     * The string used to identify Drupal user ID.
+     */
+    public const DRUPALAUTH_EXTERNAL_USER_ID = 'drupalauth:External:UserID';
 
-  /**
-   * The string used to identify Drupal user ID.
-   */
-    const DRUPALAUTH_EXTERNAL_USER_ID = 'drupalauth:External:UserID';
-
-  /**
-   * The string used to identify authentication source.
-   */
-    const DRUPALAUTH_AUTH_ID = 'drupalauth:AuthID';
+    /**
+     * The string used to identify authentication source.
+     */
+    public const DRUPALAUTH_AUTH_ID = 'drupalauth:AuthID';
 
-  /**
-   * The string used to identify our states.
-   */
-    const DRUPALAUTH_EXTERNAL = 'drupalauth:External';
+    /**
+     * The string used to identify our states.
+     */
+    public const DRUPALAUTH_EXTERNAL = 'drupalauth:External';
 
-  /**
+    /**
      * Configuration object.
      *
      * @var \SimpleSAML\Module\drupalauth\ConfigHelper
      */
-    private $config;
+    private ConfigHelper $config;
 
     /**
      * Constructor for this authentication source.
@@ -103,7 +102,7 @@ class External extends Source
      * @param array $info Information about this authentication source.
      * @param array $config Configuration.
      */
-    public function __construct($info, $config)
+    public function __construct(array $info, array $config)
     {
         assert(is_array($info));
         assert(is_array($config));
@@ -114,54 +113,56 @@ public function __construct($info, $config)
         /* Get the configuration for this module */
         $drupalAuthConfig = new ConfigHelper(
             $config,
-            'Authentication source ' . var_export($this->getAuthId(), true)
+            'Authentication source ' . $this->getAuthId()
         );
 
         $this->config = $drupalAuthConfig;
     }
 
-
     /**
      * Retrieve attributes for the user.
      *
-     * @return array|NULL  The user's attributes, or NULL if the user isn't authenticated.
+     * @return array|NULL  The user's attributes, or NULL if the user isn't
+     *     authenticated.
      */
-    private function getUser($drupaluid)
+    private function getUser($drupalUid): ?array
     {
-        if (!empty($drupaluid)) {
+        if (!empty($drupalUid)) {
             $drupalHelper = new DrupalHelper();
-            $drupalHelper->bootDrupal($this->config->getDrupalroot());
+            $drupalHelper->bootDrupal($this->config->getDrupalRoot());
 
-          // Load the user object from Drupal.
-            $drupaluser = User::load($drupaluid);
-            if ($drupaluser->isBlocked()) {
+            // Load the user object from Drupal.
+            $drupalUser = User::load($drupalUid);
+            if ($drupalUser->isBlocked()) {
                 throw new Error('NOACCESS');
             }
 
-            $requested_attributes = $this->config->getAttributes();
+            $requestedAttributes = $this->config->getAttributes();
 
-            return $drupalHelper->getAttributes($drupaluser, $requested_attributes);
+            return $drupalHelper->getAttributes($drupalUser, $requestedAttributes);
         }
+
+        return null;
     }
 
     /**
      * Log in using an external authentication helper.
      *
-     * @param array &$state  Information about the current authentication.
+     * @param array &$state Information about the current authentication.
      */
-    public function authenticate(&$state)
+    public function authenticate(array &$state): void
     {
         assert(is_array($state));
 
-      /*
+        /*
          * The user is already authenticated.
          *
          * Add the users attributes to the $state-array, and return control
          * to the authentication process.
          */
-      if (!empty($state[self::DRUPALAUTH_EXTERNAL_USER_ID])) {
-          $state['Attributes'] = $this->getUser($state[self::DRUPALAUTH_EXTERNAL_USER_ID]);
-          return;
+        if (!empty($state[self::DRUPALAUTH_EXTERNAL_USER_ID])) {
+            $state['Attributes'] = $this->getUser($state[self::DRUPALAUTH_EXTERNAL_USER_ID]);
+            return;
         }
 
         /*
@@ -206,7 +207,7 @@ public function authenticate(&$state)
          * is also part of this module, but in a real example, this would likely be
          * the absolute URL of the login page for the site.
          */
-        $authPage = $this->config->getDrupalLoginURL();
+        $authPage = $this->config->getDrupalLoginUrl();
 
         /*
          * The redirect to the authentication page.
@@ -214,7 +215,8 @@ public function authenticate(&$state)
          * Note the 'ReturnTo' parameter. This must most likely be replaced with
          * the real name of the parameter for the login page.
          */
-        HTTP::redirectTrustedURL($authPage, [
+        $http = new HTTP();
+        $http->redirectTrustedURL($authPage, [
             'ReturnTo' => $returnTo,
         ]);
 
@@ -230,7 +232,7 @@ public function authenticate(&$state)
      * This function resumes the authentication process after the user has
      * entered his or her credentials.
      *
-     * @param array &$state  The authentication state.
+     * @param array &$state The authentication state.
      */
     public static function resume($stateID)
     {
@@ -274,7 +276,7 @@ public static function resume($stateID)
          * First we check that the user is acutally logged in, and didn't simply skip the login page.
          */
         if (empty($state[self::DRUPALAUTH_EXTERNAL_USER_ID])) {
-          throw new Exception('User ID is missing.');
+            throw new Exception('User ID is missing.');
         }
 
         /*
@@ -306,12 +308,12 @@ public static function resume($stateID)
     }
 
     /**
-     * This function is called when the user start a logout operation, for example
-     * by logging out of a SP that supports single logout.
+     * This function is called when the user start a logout operation, for
+     * example by logging out of a SP that supports single logout.
      *
-     * @param array &$state  The logout state array.
+     * @param array &$state The logout state array.
      */
-    public function logout(&$state)
+    public function logout(array &$state): void
     {
         assert(is_array($state));
 
@@ -320,12 +322,13 @@ public function logout(&$state)
             session_start();
         }
 
-        $logout_url = $this->config->getDrupalLogoutURL();
+        $logoutUrl = $this->config->getDrupalLogoutUrl();
         $parameters = [];
         if (!empty($state['ReturnTo'])) {
             $parameters['ReturnTo'] = $state['ReturnTo'];
         }
 
-        HTTP::redirectTrustedURL($logout_url, $parameters);
+        $http = new HTTP();
+        $http->redirectTrustedURL($logoutUrl, $parameters);
     }
 }
diff --git a/lib/Auth/Source/UserPass.php b/src/Auth/Source/UserPass.php
similarity index 83%
rename from lib/Auth/Source/UserPass.php
rename to src/Auth/Source/UserPass.php
index fbadab3..89f5573 100644
--- a/lib/Auth/Source/UserPass.php
+++ b/src/Auth/Source/UserPass.php
@@ -3,6 +3,7 @@
 namespace SimpleSAML\Module\drupalauth\Auth\Source;
 
 use Drupal\user\Entity\User;
+use SimpleSAML\Assert\Assert;
 use SimpleSAML\Error\Error;
 use SimpleSAML\Module\core\Auth\UserPassBase;
 use SimpleSAML\Module\drupalauth\ConfigHelper;
@@ -56,13 +57,12 @@
  */
 class UserPass extends UserPassBase
 {
-
     /**
      * Configuration object.
      *
      * @var \SimpleSAML\Module\drupalauth\ConfigHelper
      */
-    private $config;
+    private ConfigHelper $config;
 
     /**
      * Constructor for this authentication source.
@@ -70,7 +70,7 @@ class UserPass extends UserPassBase
      * @param array $info Information about this authentication source.
      * @param array $config Configuration.
      */
-    public function __construct($info, $config)
+    public function __construct(array $info, array $config)
     {
         assert(is_array($info));
         assert(is_array($config));
@@ -81,7 +81,7 @@ public function __construct($info, $config)
         /* Get the configuration for this module */
         $drupalAuthConfig = new ConfigHelper(
             $config,
-            'Authentication source ' . var_export($this->getAuthId(), true)
+            'Authentication source ' . $this->getAuthId()
         );
 
         $this->config = $drupalAuthConfig;
@@ -91,23 +91,25 @@ public function __construct($info, $config)
     /**
      * Attempt to log in using the given username and password.
      *
-     * On a successful login, this function should return the users attributes. On failure,
-     * it should throw an exception. If the error was caused by the user entering the wrong
-     * username or password, a SimpleSAML_Error_Error('WRONGUSERPASS') should be thrown.
+     * On a successful login, this function should return the users attributes.
+     * On failure, it should throw an exception. If the error was caused by the
+     * user entering the wrong username or password, a
+     * SimpleSAML_Error_Error('WRONGUSERPASS') should be thrown.
      *
      * Note that both the username and the password are UTF-8 encoded.
      *
      * @param string $username The username the user wrote.
      * @param string $password The password the user wrote.
+     *
      * @return array  Associative array with the users attributes.
      */
-    protected function login($username, $password)
+    protected function login(string $username, string $password): array
     {
         assert(is_string($username));
         assert(is_string($password));
 
         $drupalHelper = new DrupalHelper();
-        $drupalHelper->bootDrupal($this->config->getDrupalroot());
+        $drupalHelper->bootDrupal($this->config->getDrupalRoot());
 
         /* @value \Drupal\user\UserAuth $userAuth */
         $userAuth = \Drupal::service('user.auth');
@@ -119,13 +121,13 @@ protected function login($username, $password)
         }
 
         // Load the user object from Drupal.
-        $drupaluser = User::load($uid);
-        if ($drupaluser->isBlocked()) {
+        $drupalUser = User::load($uid);
+        if ($drupalUser->isBlocked()) {
             throw new Error('NOACCESS');
         }
 
-        $requested_attributes = $this->config->getAttributes();
+        $requestedAttributes = $this->config->getAttributes();
 
-        return $drupalHelper->getAttributes($drupaluser, $requested_attributes);
+        return $drupalHelper->getAttributes($drupalUser, $requestedAttributes);
     }
 }
diff --git a/src/ConfigHelper.php b/src/ConfigHelper.php
new file mode 100644
index 0000000..4a9457a
--- /dev/null
+++ b/src/ConfigHelper.php
@@ -0,0 +1,78 @@
+<?php
+
+namespace SimpleSAML\Module\drupalauth;
+
+use SimpleSAML\Configuration;
+
+/**
+ * Drupal authentication source configuration parser.
+ */
+class ConfigHelper
+{
+    /**
+     * @var \SimpleSAML\Configuration
+     */
+    private Configuration $config;
+
+    /**
+     * Constructor for this configuration parser.
+     *
+     * @param array $config  Configuration.
+     * @param string $location  The location of this configuration. Used for error reporting.
+     */
+    public function __construct(array $config, string $location)
+    {
+        $this->config = Configuration::loadFromArray($config, $location);
+    }
+
+    /**
+     * Returns debug mode.
+     *
+     * @return bool
+     */
+    public function getDebug(): bool
+    {
+        return $this->config->getOptionalBoolean('debug', false);
+    }
+
+    /**
+     * Returns Drupal root directory.
+     *
+     * @return string
+     */
+    public function getDrupalRoot(): string
+    {
+        return $this->config->getString('drupalroot');
+    }
+
+  /**
+   * Return the attributes
+   *
+   * @return array
+   */
+    public function getAttributes(): ?array
+    {
+        return $this->config->getOptionalArray('attributes', null);
+    }
+
+
+    /**
+     * Returns Drupal logout URL.
+     *
+     * @return string
+   */
+    public function getDrupalLogoutUrl(): string
+    {
+        return $this->config->getString('drupal_logout_url');
+    }
+
+  /**
+   * Returns Drupal login URL.
+   *
+   * @return string
+   */
+    public function getDrupalLoginUrl(): string
+    {
+        return $this->config->getString('drupal_login_url');
+    }
+}
diff --git a/lib/DrupalHelper.php b/src/DrupalHelper.php
similarity index 97%
rename from lib/DrupalHelper.php
rename to src/DrupalHelper.php
index 40f6bbe..8488c55 100644
--- a/lib/DrupalHelper.php
+++ b/src/DrupalHelper.php
@@ -1,6 +1,5 @@
 <?php
 
-
 namespace SimpleSAML\Module\drupalauth;
 
 use Drupal\Core\DrupalKernel;
@@ -8,15 +7,14 @@
 
 class DrupalHelper
 {
-
-    private $forbiddenAttributes = ['pass', 'status'];
+    private array $forbiddenAttributes = ['pass', 'status'];
 
     /**
      * Boot Drupal.
      *
      * @param string $drupalRoot Path to Drupal root.
      */
-    public function bootDrupal($drupalRoot)
+    public function bootDrupal(string $drupalRoot)
     {
         $autoloader = require_once $drupalRoot . '/autoload.php';
         $request = Request::createFromGlobals();
@@ -34,7 +32,7 @@ public function bootDrupal($drupalRoot)
      * @param $forbiddenAttributes
      * @return array
      */
-    public function getAttributes($drupaluser, $requested_attributes)
+    public function getAttributes($drupaluser, $requested_attributes): array
     {
         $attributes = [];
         $forbiddenAttributes = $this->forbiddenAttributes;
@@ -89,7 +87,7 @@ public function getAttributes($drupaluser, $requested_attributes)
      * @param $forbiddenAttributes
      * @return array
      */
-    protected function getAllAttributes($drupaluser, $forbiddenAttributes)
+    protected function getAllAttributes($drupaluser, $forbiddenAttributes): array
     {
         $attributes = [];
         foreach ($drupaluser as $field_name => $field) {
diff --git a/tests/lib/DrupalHelperTest.php b/tests/DrupalHelperTest.php
similarity index 97%
rename from tests/lib/DrupalHelperTest.php
rename to tests/DrupalHelperTest.php
index 26c9d97..3fa3c84 100644
--- a/tests/lib/DrupalHelperTest.php
+++ b/tests/DrupalHelperTest.php
@@ -14,7 +14,7 @@ class DrupalHelperTest extends TestCase
     /**
      * @var ReflectionClass
      */
-    protected $class;
+    protected ReflectionClass $class;
 
     protected function setUp(): void
     {
@@ -24,7 +24,7 @@ protected function setUp(): void
     }
 
 
-    public function getPropertyNameProvider()
+    public static function getPropertyNameProvider(): array
     {
         return [
             [[], 'value'],
@@ -46,7 +46,7 @@ public function testGetPropertyName($attribute_definition, $expected_property_na
     }
 
 
-    public function getAttributeNameProvider()
+    public static function getAttributeNameProvider(): array
     {
         return [
             [['field_name' => 'some_field'], 'some_field:value'],
@@ -73,7 +73,7 @@ public function testGetAttributeName($attribute_definition, $expected_attribute_
         $this->assertEquals($expected_attribute_name, $attribute_name, 'Expected attribute name returned');
     }
 
-    public function getAllAttributesDataProvider()
+    public static function getAllAttributesDataProvider(): array
     {
         return [
             // Set #0.
@@ -180,7 +180,7 @@ public function testGetAllAttributes($values, $forbidden_attributes, $expected_a
         $this->assertEquals($expected_attributes, $attributes, 'Expected attributes returned');
     }
 
-    public function getAttributesDataProvider()
+    public static function getAttributesDataProvider(): array
     {
         $field_values = [
             'field_name' => [
diff --git a/tests/lib/Field.php b/tests/Field.php
similarity index 67%
rename from tests/lib/Field.php
rename to tests/Field.php
index 85a4697..a7afa9f 100644
--- a/tests/lib/Field.php
+++ b/tests/Field.php
@@ -9,7 +9,7 @@
 class Field
 {
 
-    protected $properties = [];
+    protected array $properties = [];
 
     public function __set($name, $value)
     {
@@ -18,11 +18,11 @@ public function __set($name, $value)
 
     public function __get($name)
     {
-        return isset($this->properties[$name]) ? $this->properties[$name] : null;
+        return $this->properties[$name] ?? null;
     }
 
 
-    public function getProperties()
+    public function getProperties(): array
     {
         return array_keys($this->properties);
     }
diff --git a/tests/lib/FieldList.php b/tests/FieldList.php
similarity index 94%
rename from tests/lib/FieldList.php
rename to tests/FieldList.php
index 2cc13fa..7409bfe 100644
--- a/tests/lib/FieldList.php
+++ b/tests/FieldList.php
@@ -8,7 +8,7 @@
 
 class FieldList
 {
-    protected $list = [];
+    protected array $list = [];
 
     public function get($index)
     {
@@ -16,7 +16,7 @@ public function get($index)
             throw new \InvalidArgumentException('Unable to get a value with a non-numeric delta in a list.');
         }
 
-        return isset($this->list[$index]) ? $this->list[$index] : null;
+        return $this->list[$index] ?? null;
     }
 
     public function set($index, $properties)
diff --git a/tests/lib/FieldListTest.php b/tests/FieldListTest.php
similarity index 100%
rename from tests/lib/FieldListTest.php
rename to tests/FieldListTest.php
diff --git a/tests/lib/FieldTest.php b/tests/FieldTest.php
similarity index 100%
rename from tests/lib/FieldTest.php
rename to tests/FieldTest.php
diff --git a/tests/lib/PropertyDefinition.php b/tests/PropertyDefinition.php
similarity index 100%
rename from tests/lib/PropertyDefinition.php
rename to tests/PropertyDefinition.php
diff --git a/tests/lib/PropertyDefinitionTest.php b/tests/PropertyDefinitionTest.php
similarity index 100%
rename from tests/lib/PropertyDefinitionTest.php
rename to tests/PropertyDefinitionTest.php
diff --git a/tests/lib/User.php b/tests/User.php
similarity index 87%
rename from tests/lib/User.php
rename to tests/User.php
index 0c8e7f5..caa4ab1 100644
--- a/tests/lib/User.php
+++ b/tests/User.php
@@ -2,7 +2,7 @@
 
 class User implements IteratorAggregate
 {
-    protected $fields = [];
+    protected array $fields = [];
 
     /**
      * User constructor.
@@ -11,7 +11,7 @@ class User implements IteratorAggregate
      *   Each key corresponds to field name. Each value either scalar or array. Scalar would would be treated as index 0
      *   value of 'value' property. In case of array
      */
-    public function __construct($values)
+    public function __construct(array $values)
     {
         foreach ($values as $field_name => $field_value) {
             $this->fields[$field_name] = new FieldList();
@@ -37,6 +37,6 @@ public function hasField($field_name)
 
     public function __get($field_name)
     {
-        return isset($this->fields[$field_name]) ? $this->fields[$field_name] : null;
+        return $this->fields[$field_name] ?? null;
     }
 }
diff --git a/tests/lib/UserTest.php b/tests/UserTest.php
similarity index 97%
rename from tests/lib/UserTest.php
rename to tests/UserTest.php
index 60b4f27..dabaa48 100644
--- a/tests/lib/UserTest.php
+++ b/tests/UserTest.php
@@ -11,7 +11,7 @@
 class UserTest extends TestCase
 {
 
-    public function userDataProvider()
+    public static function userDataProvider()
     {
         return [
             [
@@ -58,7 +58,7 @@ public function testUser($values, $count)
         $this->assertEquals($count, count($user->getIterator()), 'Returned expected quantity of fields');
     }
 
-    public function userHasFieldDataProvider()
+    public static function userHasFieldDataProvider()
     {
         return [
             [