diff --git a/.travis.yml b/.travis.yml
index e1b5c20..e7d62d0 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,6 +1,8 @@
 language: php
 php:
-  - 7.0
+  - 7.2
+  - 7.3
+
 install:
  - composer self-update
  - composer install --no-interaction --dev
diff --git a/composer.json b/composer.json
index 5f8bff3..f5302f7 100644
--- a/composer.json
+++ b/composer.json
@@ -10,14 +10,14 @@
     "homepage": "https://nohponex.gr"
   }],
   "require": {
-    "php": ">=7",
+    "php": "^7.2 | ^8.0.0",
     "phramework/phramework": "1.*",
     "ext-json": "*",
     "phramework/util": "^0.0.0"
   },
   "require-dev": {
-    "squizlabs/php_codesniffer": "*",
-    "phpunit/phpunit": "5.*",
+    "squizlabs/php_codesniffer": "^3.5.3",
+    "phpunit/phpunit": "^8.4.3",
     "apigen/apigen": "^4.1",
     "satooshi/php-coveralls": "^2.0.0",
     "codacy/coverage": "^1.0"
diff --git a/phpunit.xml b/phpunit.xml
index 8abaa88..f1be68c 100644
--- a/phpunit.xml
+++ b/phpunit.xml
@@ -13,7 +13,7 @@
  <logging>
      <log type="tap" target="build/report.tap"/>
      <log type="junit" target="build/report.junit.xml"/>
-     <log type="coverage-html" target="build/coverage" charset="UTF-8" yui="true" highlight="true"/>
+     <log type="coverage-html" target="build/coverage" />
      <log type="coverage-text" target="build/coverage.txt"/>
      <log type="coverage-clover" target="build/logs/clover.xml"/>
  </logging>
diff --git a/tests/src/ControllerTest.php b/tests/src/ControllerTest.php
deleted file mode 100644
index 455bcb8..0000000
--- a/tests/src/ControllerTest.php
+++ /dev/null
@@ -1,61 +0,0 @@
-<?php
-/**
- * Copyright 2015 - 2016 Xenofon Spafaridis
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-namespace Phramework\JSONAPI;
-
-use \Phramework\Phramework;
-
-/**
- * @license https://www.apache.org/licenses/LICENSE-2.0 Apache-2.0
- * @author Xenofon Spafaridis <nohponex@gmail.com>
- */
-class ControllerTest extends \PHPUnit_Framework_TestCase
-{
-    /**
-     * Sets up the fixture, for example, opens a network connection.
-     * This method is called before a test is executed.
-     * @todo update base
-     */
-    protected function setUp()
-    {
-    }
-
-    /**
-     * Tears down the fixture, for example, closes a network connection.
-     * This method is called after a test is executed.
-     */
-    protected function tearDown()
-    {
-    }
-
-    public function testExtends()
-    {
-        $controller = \Phramework\JSONAPI\Controller::class;
-
-        $classes = [
-            \Phramework\JSONAPI\Controller\Base::class,
-            \Phramework\JSONAPI\Controller\GET::class
-        ];
-
-        /*foreach ($classes as $class) {
-            $this->assertTrue(is_a(
-                $controller,
-                $class,
-                true
-            ));
-        }*/
-    }
-}
diff --git a/tests/src/Controllers/DELETETest.php b/tests/src/Controllers/DELETETest.php
index ebb8541..693fa4e 100644
--- a/tests/src/Controllers/DELETETest.php
+++ b/tests/src/Controllers/DELETETest.php
@@ -17,13 +17,14 @@
 namespace Phramework\JSONAPI\Controller;
 
 use \Phramework\Phramework;
+use PHPUnit\Framework\TestCase;
 
 /**
  * @coversDefaultClass \Phramework\JSONAPI\Controller\DELETE
  * @license https://www.apache.org/licenses/LICENSE-2.0 Apache-2.0
  * @author Xenofon Spafaridis <nohponex@gmail.com>
  */
-class DELETETest extends \PHPUnit_Framework_TestCase
+class DELETETest extends TestCase
 {
     /**
      * @var Phramework
@@ -36,14 +37,6 @@ class DELETETest extends \PHPUnit_Framework_TestCase
      */
     protected $parameters;
 
-    /**
-     * Sets up the fixture, for example, opens a network connection.
-     * This method is called before a test is executed.
-     */
-    protected function setUp()
-    {
-    }
-
     protected function prepare()
     {
         $_SERVER['REQUEST_URI'] = '/article/1';
@@ -70,7 +63,7 @@ function (
     /**
      * @covers ::handleDELETE
      */
-    public function testDELETESuccess()
+    public function testDELETESuccess(): void
     {
         $this->prepare();
 
@@ -80,15 +73,15 @@ public function testDELETESuccess()
         $params = $this->parameters;
         return;
 
-        $this->assertInternalType('object', $params);
+        $this->assertIsObject($params);
 
         $this->assertObjectHasAttribute('links', $params);
         $this->assertObjectHasAttribute('data', $params);
 
-        $this->assertInternalType('object', $params->data);
+        $this->assertIsObject($params->data);
         $this->assertObjectHasAttribute('id', $params->data);
 
-        $this->assertInternalType('string', $params->data->id);
+        $this->assertIsString($params->data->id);
 
         $id = $params->data->id;
 
@@ -97,7 +90,7 @@ public function testDELETESuccess()
 
         $article = \Phramework\JSONAPI\APP\Models\Article::getById($id);
 
-        $this->assertInternalType('object', $article);
+        $this->assertIsObject($article);
 
         $this->assertObjectHasAttribute('attributes', $article);
         $this->assertObjectHasAttribute('relationships', $article);
@@ -107,7 +100,7 @@ public function testDELETESuccess()
         $this->assertObjectHasAttribute('creator', $relationships);
         $this->assertObjectHasAttribute('tag', $relationships);
 
-        $this->assertInternalType('object', $relationships->creator->data);
+        $this->assertIsObject($relationships->creator->data);
         $this->assertInternalType('array', $relationships->tag->data);
 
         $this->assertEquals('1', $relationships->creator->data->id);
@@ -120,7 +113,7 @@ public function testDELETESuccess()
      * Cause a not found exception, at to TYPE_TO_ONE relationship
      * @covers \Phramework\JSONAPI\Controller\DELETE::handleDELETE
      */
-    public function testDELETEFailureToOne()
+    public function testDELETEFailureToOne(): void
     {
         $this->prepare();
 
@@ -132,7 +125,7 @@ public function testDELETEFailureToOne()
         //Access parameters written by invoked phramework's viewer
         $params = $this->parameters;
 
-        $this->assertInternalType('object', $params);
+        $this->assertIsObject($params);
         $this->assertObjectHasAttribute('errors', $params);
 
         $this->assertSame(
@@ -146,7 +139,7 @@ public function testDELETEFailureToOne()
      * Cause a not found exception, at to TYPE_TO_MANY relationship
      * @covers \Phramework\JSONAPI\Controller\DELETE::handleDELETE
      */
-    public function testDELETEFailureToMany()
+    public function testDELETEFailureToMany(): void
     {
         return;
         $this->prepare();
@@ -159,7 +152,7 @@ public function testDELETEFailureToMany()
         //Access parameters written by invoked phramework's viewer
         $params = $this->parameters;
 
-        $this->assertInternalType('object', $params);
+        $this->assertIsObject($params);
         $this->assertObjectHasAttribute('errors', $params);
 
         $this->assertSame(
diff --git a/tests/src/Controllers/GETByIdTest.php b/tests/src/Controllers/GETByIdTest.php
index e78a716..962b9de 100644
--- a/tests/src/Controllers/GETByIdTest.php
+++ b/tests/src/Controllers/GETByIdTest.php
@@ -17,13 +17,14 @@
 namespace Phramework\JSONAPI\Controller;
 
 use \Phramework\Phramework;
+use PHPUnit\Framework\TestCase;
 
 /**
  * @coversDefaultClass \Phramework\JSONAPI\Controller\GETById
  * @license https://www.apache.org/licenses/LICENSE-2.0 Apache-2.0
  * @author Xenofon Spafaridis <nohponex@gmail.com>
  */
-class GETByIdTest extends \PHPUnit_Framework_TestCase
+class GETByIdTest extends TestCase
 {
     /**
      * @var Phramework
@@ -36,15 +37,7 @@ class GETByIdTest extends \PHPUnit_Framework_TestCase
      */
     protected $parameters;
 
-    /**
-     * Sets up the fixture, for example, opens a network connection.
-     * This method is called before a test is executed.
-     */
-    protected function setUp()
-    {
-    }
-
-    protected function prepare()
+    protected function prepare(): void
     {
         $_SERVER['REQUEST_URI'] = 'article/1';
         $_SERVER['REQUEST_METHOD'] = Phramework::METHOD_GET;
@@ -71,7 +64,7 @@ function (
     /**
      * @covers ::handleGETById
      */
-    public function testGETByIdSuccess()
+    public function testGETByIdSuccess(): void
     {
         $this->prepare();
 
@@ -81,12 +74,12 @@ public function testGETByIdSuccess()
         $params = $this->parameters;
 
 
-        $this->assertInternalType('object', $params);
+        $this->assertIsObject($params);
 
         $this->assertObjectHasAttribute('links', $params);
         $this->assertObjectHasAttribute('data', $params);
 
-        $this->assertInternalType('object', $params->data);
+        $this->assertIsObject($params->data);
         $this->assertObjectHasAttribute('id', $params->data);
 
         return;
@@ -100,7 +93,7 @@ public function testGETByIdSuccess()
 
         $article = \Phramework\JSONAPI\APP\Models\Article::getById($id);
 
-        $this->assertInternalType('object', $article);
+        $this->assertIsObject($article);
 
         $this->assertObjectHasAttribute('attributes', $article);
         $this->assertObjectHasAttribute('relationships', $article);
@@ -110,7 +103,7 @@ public function testGETByIdSuccess()
         $this->assertObjectHasAttribute('creator', $relationships);
         $this->assertObjectHasAttribute('tag', $relationships);
 
-        $this->assertInternalType('object', $relationships->creator->data);
+        $this->assertIsObject($relationships->creator->data);
         $this->assertInternalType('array', $relationships->tag->data);
 
         $this->assertEquals('1', $relationships->creator->data->id);
@@ -122,7 +115,7 @@ public function testGETByIdSuccess()
     /**
      * @covers \Phramework\JSONAPI\Controller\DELETE::handleDELETE
      */
-    public function testDELETEFailureNotFound()
+    public function testDELETEFailureNotFound(): void
     {
         $this->prepare();
 
@@ -134,7 +127,7 @@ public function testDELETEFailureNotFound()
         //Access parameters returned by invoked phramework's viewer
         $params = $this->parameters;
 
-        $this->assertInternalType('object', $params);
+        $this->assertIsObject($params);
         $this->assertObjectHasAttribute('errors', $params);
 
         $this->assertSame(
@@ -147,7 +140,7 @@ public function testDELETEFailureNotFound()
     /**
      * @covers \Phramework\JSONAPI\Controller\DELETE::handleDELETE
      */
-    public function testHandleFailure()
+    public function testHandleFailure(): void
     {
         $this->prepare();
 
@@ -158,7 +151,7 @@ public function testHandleFailure()
         //Access parameters returned by invoked phramework's viewer
         $params = $this->parameters;
 
-        $this->assertInternalType('object', $params);
+        $this->assertIsObject($params);
         $this->assertObjectHasAttribute('errors', $params);
 
         $this->assertSame(
diff --git a/tests/src/Controllers/GETTest.php b/tests/src/Controllers/GETTest.php
index e9ebb85..13e9cfd 100644
--- a/tests/src/Controllers/GETTest.php
+++ b/tests/src/Controllers/GETTest.php
@@ -18,13 +18,14 @@
 
 use Phramework\JSONAPI\APP\Bootstrap;
 use \Phramework\Phramework;
+use PHPUnit\Framework\TestCase;
 
 /**
  * @coversDefaultClass \Phramework\JSONAPI\Controller\GET
  * @license https://www.apache.org/licenses/LICENSE-2.0 Apache-2.0
  * @author Xenofon Spafaridis <nohponex@gmail.com>
  */
-class GETTest extends \PHPUnit_Framework_TestCase
+class GETTest extends TestCase
 {
     /**
      * @var Phramework
@@ -36,15 +37,6 @@ class GETTest extends \PHPUnit_Framework_TestCase
      */
     protected $parameters;
 
-    /**
-     * Sets up the fixture, for example, opens a network connection.
-     * This method is called before a test is executed.
-     * @todo update base
-     */
-    protected function setUp()
-    {
-    }
-
     protected function prepare()
     {
         $_SERVER['REQUEST_URI'] = '/article/';
@@ -69,18 +61,11 @@ function (
         );
     }
 
-    /**
-     * Tears down the fixture, for example, closes a network connection.
-     * This method is called after a test is executed.
-     */
-    protected function tearDown()
-    {
-    }
 
     /**
      * @covers Phramework\JSONAPI\Controller\GET::handleGET
      */
-    public function testHandleGet()
+    public function testHandleGet(): void
     {
         $this->prepare();
 
diff --git a/tests/src/Controllers/PATCHTest.php b/tests/src/Controllers/PATCHTest.php
index bb47686..4a53873 100644
--- a/tests/src/Controllers/PATCHTest.php
+++ b/tests/src/Controllers/PATCHTest.php
@@ -18,13 +18,14 @@
 
 use Phramework\JSONAPI\APP\Models\User;
 use \Phramework\Phramework;
+use PHPUnit\Framework\TestCase;
 
 /**
  * @coversDefaultClass \Phramework\JSONAPI\Controller\PATCH
  * @license https://www.apache.org/licenses/LICENSE-2.0 Apache-2.0
  * @author Xenofon Spafaridis <nohponex@gmail.com>
  */
-class PATCHTest extends \PHPUnit_Framework_TestCase
+class PATCHTest extends TestCase
 {
     /**
      * @var Phramework
@@ -36,14 +37,6 @@ class PATCHTest extends \PHPUnit_Framework_TestCase
      */
     protected $parameters;
 
-    /**
-     * Sets up the fixture, for example, opens a network connection.
-     * This method is called before a test is executed.
-     */
-    protected function setUp()
-    {
-    }
-
     protected function prepare()
     {
         $_SERVER['REQUEST_URI'] = '/article/1';
@@ -99,7 +92,7 @@ function (
     /**
      * @covers ::handlePATCH
      */
-    public function testPATCHSuccess()
+    public function testPATCHSuccess(): void
     {
         $this->prepare();
         $this->phramework->invoke();
@@ -110,12 +103,12 @@ public function testPATCHSuccess()
 
         return;
 
-        $this->assertInternalType('object', $parameters);
+        $this->assertIsObject($parameters);
 
         $this->assertObjectHasAttribute('links', $parameters);
         $this->assertObjectHasAttribute('data', $parameters);
 
-        $this->assertInternalType('object', $parameters->data);
+        $this->assertIsObject($parameters->data);
         $this->assertObjectHasAttribute('id', $parameters->data);
 
         $this->assertInternalType('string', $parameters->data->id);
@@ -127,7 +120,7 @@ public function testPATCHSuccess()
 
         $article = \Phramework\JSONAPI\APP\Models\Article::getById($id);
 
-        $this->assertInternalType('object', $article);
+        $this->assertIsObject($article);
 
         $this->assertObjectHasAttribute('attributes', $article);
         $this->assertObjectHasAttribute('relationships', $article);
@@ -137,7 +130,7 @@ public function testPATCHSuccess()
         $this->assertObjectHasAttribute('creator', $relationships);
         $this->assertObjectHasAttribute('tag', $relationships);
 
-        $this->assertInternalType('object', $relationships->creator->data);
+        $this->assertIsObject($relationships->creator->data);
         $this->assertInternalType('array', $relationships->tag->data);
 
         $this->assertEquals('1', $relationships->creator->data->id);
@@ -150,7 +143,7 @@ public function testPATCHSuccess()
      * Cause a not found exception, at to TYPE_TO_ONE relationship
      * @covers \Phramework\JSONAPI\Controller\PATCH::handlePATCH
      */
-    public function testPATCHFailureToOne()
+    public function testPATCHFailureToOne(): void
     {
         $this->prepare();
 
@@ -162,7 +155,7 @@ public function testPATCHFailureToOne()
         //Access parameters written by invoked phramework's viewer
         $params = $this->parameters;
 
-        $this->assertInternalType('object', $params);
+        $this->assertIsObject($params);
         $this->assertObjectHasAttribute('errors', $params);
 
         $this->assertSame(
@@ -176,7 +169,7 @@ public function testPATCHFailureToOne()
      * Cause a not found exception, at to TYPE_TO_MANY relationship
      * @covers \Phramework\JSONAPI\Controller\PATCH::handlePATCH
      */
-    public function testPATCHFailureToMany()
+    public function testPATCHFailureToMany(): void
     {
         $this->prepare();
 
@@ -188,7 +181,7 @@ public function testPATCHFailureToMany()
         //Access parameters written by invoked phramework's viewer
         $params = $this->parameters;
 
-        $this->assertInternalType('object', $params);
+        $this->assertIsObject($params);
         $this->assertObjectHasAttribute('errors', $params);
 
         $this->assertSame(
diff --git a/tests/src/Controllers/POSTTest.php b/tests/src/Controllers/POSTTest.php
index deeb9df..7091bd4 100644
--- a/tests/src/Controllers/POSTTest.php
+++ b/tests/src/Controllers/POSTTest.php
@@ -17,6 +17,7 @@
 namespace Phramework\JSONAPI\Controller;
 
 use \Phramework\Phramework;
+use PHPUnit\Framework\TestCase;
 
 /**
  * @todo test wrong relationship
@@ -25,7 +26,7 @@
  * @license https://www.apache.org/licenses/LICENSE-2.0 Apache-2.0
  * @author Xenofon Spafaridis <nohponex@gmail.com>
  */
-class POSTTest extends \PHPUnit_Framework_TestCase
+class POSTTest extends TestCase
 {
     /**
      * @var Phramework
@@ -37,15 +38,7 @@ class POSTTest extends \PHPUnit_Framework_TestCase
      */
     protected $params;
 
-    /**
-     * Sets up the fixture, for example, opens a network connection.
-     * This method is called before a test is executed.
-     */
-    protected function setUp()
-    {
-    }
-
-    protected function prepare()
+    protected function prepare(): void
     {
         //ob_start();
         $_SERVER['REQUEST_URI'] = '/article/';
@@ -98,22 +91,10 @@ function (
         //ob_end_clean();
     }
 
-    /**
-     * Tears down the fixture, for example, closes a network connection.
-     * This method is called after a test is executed.
-     */
-    protected function tearDown()
-    {
-        //\Phramework\JSONAPI\APP\Viewers\Viewer::release(__CLASS__);
-        //foreach ($this->buffer as $line) {
-        //    print_r($line);
-        //}
-    }
-
     /**
      * @covers \Phramework\JSONAPI\Controller\POST::handlePOSTResource
      */
-    public function testHandlePOSTResource()
+    public function testHandlePOSTResource(): void
     {
         $this->testPOSTSuccess();
     }
@@ -121,7 +102,7 @@ public function testHandlePOSTResource()
     /**
      * @covers \Phramework\JSONAPI\Controller\POST::handlePOST
      */
-    public function testPOSTSuccess()
+    public function testPOSTSuccess(): void
     {
         $this->prepare();
         //ob_clean();
@@ -132,12 +113,12 @@ public function testPOSTSuccess()
         $params = $this->params;
         return;
 
-        $this->assertInternalType('object', $params);
+        $this->assertIsObject($params);
 
         $this->assertObjectHasAttribute('links', $params);
         $this->assertObjectHasAttribute('data', $params);
 
-        $this->assertInternalType('object', $params->data);
+        $this->assertIsObject($params->data);
         $this->assertObjectHasAttribute('id', $params->data);
 
         $this->assertInternalType('string', $params->data->id);
@@ -149,7 +130,7 @@ public function testPOSTSuccess()
 
         $article = \Phramework\JSONAPI\APP\Models\Article::getById($id);
 
-        $this->assertInternalType('object', $article);
+        $this->assertIsObject($article);
 
         $this->assertObjectHasAttribute('attributes', $article);
         $this->assertObjectHasAttribute('relationships', $article);
@@ -159,7 +140,7 @@ public function testPOSTSuccess()
         $this->assertObjectHasAttribute('creator', $relationships);
         $this->assertObjectHasAttribute('tag', $relationships);
 
-        $this->assertInternalType('object', $relationships->creator->data);
+        $this->assertIsObject($relationships->creator->data);
         $this->assertInternalType('array', $relationships->tag->data);
 
         $this->assertEquals('1', $relationships->creator->data->id);
@@ -172,7 +153,7 @@ public function testPOSTSuccess()
      * Cause a not found exception, at to TYPE_TO_ONE relationship
      * @covers \Phramework\JSONAPI\Controller\POST::handlePOST
      */
-    public function testPOSTFailureToOne()
+    public function testPOSTFailureToOne(): void
     {
         $this->prepare();
 
@@ -184,7 +165,7 @@ public function testPOSTFailureToOne()
         //Access parameters written by invoked phramework's viewer
         $params = $this->params;
 
-        $this->assertInternalType('object', $params);
+        $this->assertIsObject($params);
         $this->assertObjectHasAttribute('errors', $params);
 
         $this->assertSame(
@@ -198,7 +179,7 @@ public function testPOSTFailureToOne()
      * Cause a not found exception, at to TYPE_TO_MANY relationship
      * @covers \Phramework\JSONAPI\Controller\POST::handlePOST
      */
-    public function testPOSTFailureToMany()
+    public function testPOSTFailureToMany(): void
     {
         $this->prepare();
 
@@ -210,7 +191,7 @@ public function testPOSTFailureToMany()
         //Access parameters written by invoked phramework's viewer
         $params = $this->params;
 
-        $this->assertInternalType('object', $params);
+        $this->assertIsObject($params);
         $this->assertObjectHasAttribute('errors', $params);
 
         $this->assertSame(
diff --git a/tests/src/Controllers/RelationshipsTest.php b/tests/src/Controllers/RelationshipsTest.php
index 0a65062..2631e86 100644
--- a/tests/src/Controllers/RelationshipsTest.php
+++ b/tests/src/Controllers/RelationshipsTest.php
@@ -17,13 +17,14 @@
 namespace Phramework\JSONAPI\Controller;
 
 use \Phramework\Phramework;
+use PHPUnit\Framework\TestCase;
 
 /**
  * @coversDefaultClass \Phramework\JSONAPI\Controller\Relationships
  * @license https://www.apache.org/licenses/LICENSE-2.0 Apache-2.0
  * @author Xenofon Spafaridis <nohponex@gmail.com>
  */
-class RelationshipsTest extends \PHPUnit_Framework_TestCase
+class RelationshipsTest extends TestCase
 {
     /**
      * @var Phramework
@@ -36,15 +37,7 @@ class RelationshipsTest extends \PHPUnit_Framework_TestCase
      */
     protected $parameters;
 
-    /**
-     * Sets up the fixture, for example, opens a network connection.
-     * This method is called before a test is executed.
-     */
-    protected function setUp()
-    {
-    }
-
-    protected function prepare()
+    protected function prepare(): void
     {
         $_SERVER['REQUEST_URI'] = '/article/1/relationships/tag/';
         $_SERVER['REQUEST_METHOD'] = Phramework::METHOD_GET;
@@ -70,7 +63,7 @@ function (
     /**
      * @covers ::handleByIdRelationships
      */
-    public function testGETByIdSuccess()
+    public function testGETByIdSuccess(): void
     {
         $this->prepare();
 
@@ -80,14 +73,14 @@ public function testGETByIdSuccess()
         $params = $this->parameters;
 
 
-        $this->assertInternalType('object', $params);
+        $this->assertIsObject($params);
 
         $this->assertObjectHasAttribute('links', $params);
         $this->assertObjectHasAttribute('data', $params);
 
         return;
 
-        $this->assertInternalType('object', $params->data);
+        $this->assertIsObject($params->data);
         $this->assertObjectHasAttribute('id', $params->data);
 
         $this->assertInternalType('string', $params->data->id);
@@ -99,7 +92,7 @@ public function testGETByIdSuccess()
 
         $article = \Phramework\JSONAPI\APP\Models\Article::getById($id);
 
-        $this->assertInternalType('object', $article);
+        $this->assertIsObject($article);
 
         $this->assertObjectHasAttribute('attributes', $article);
         $this->assertObjectHasAttribute('relationships', $article);
@@ -109,7 +102,7 @@ public function testGETByIdSuccess()
         $this->assertObjectHasAttribute('creator', $relationships);
         $this->assertObjectHasAttribute('tag', $relationships);
 
-        $this->assertInternalType('object', $relationships->creator->data);
+        $this->assertIsObject($relationships->creator->data);
         $this->assertInternalType('array', $relationships->tag->data);
 
         $this->assertEquals('1', $relationships->creator->data->id);
@@ -121,7 +114,7 @@ public function testGETByIdSuccess()
     /**
      * @covers ::handleByIdRelationships
      */
-    public function testDELETEFailureNotFound()
+    public function testDELETEFailureNotFound(): void
     {
         $this->prepare();
 
@@ -133,7 +126,7 @@ public function testDELETEFailureNotFound()
         //Access parameters returned by invoked phramework's viewer
         $params = $this->parameters;
 
-        $this->assertInternalType('object', $params);
+        $this->assertIsObject($params);
         $this->assertObjectHasAttribute('errors', $params);
 
         $this->assertSame(
@@ -146,7 +139,7 @@ public function testDELETEFailureNotFound()
     /**
      * @covers ::handleByIdRelationships
      */
-    public function testHandleFailure()
+    public function testHandleFailure(): void
     {
         $this->prepare();
 
@@ -157,7 +150,7 @@ public function testHandleFailure()
         //Access parameters returned by invoked phramework's viewer
         $params = $this->parameters;
 
-        $this->assertInternalType('object', $params);
+        $this->assertIsObject($params);
         $this->assertObjectHasAttribute('errors', $params);
 
         $this->assertSame(
diff --git a/tests/src/FieldsTest.php b/tests/src/FieldsTest.php
index 8f74ee0..cd44a50 100644
--- a/tests/src/FieldsTest.php
+++ b/tests/src/FieldsTest.php
@@ -17,6 +17,8 @@
 namespace Phramework\JSONAPI;
 
 use Exception;
+use PHPUnit\Framework\TestCase;
+use Phramework\Exceptions\IncorrectParametersException;
 use Phramework\JSONAPI\APP\Models\Article;
 use Phramework\JSONAPI\APP\Models\Tag;
 
@@ -25,14 +27,14 @@
  * @license https://www.apache.org/licenses/LICENSE-2.0 Apache-2.0
  * @author Xenofon Spafaridis <nohponex@gmail.com>
  */
-class FieldsTest extends \PHPUnit_Framework_TestCase
+class FieldsTest extends TestCase
 {
     /**
      * @var Fields
      */
     protected $fields;
 
-    public function setUp()
+    public function setUp(): void
     {
         $this->fields = new Fields();
     }
@@ -44,7 +46,7 @@ public function testConstruct1()
     {
         $fieldsInstance = new Fields();
 
-        $this->assertInternalType('object', $fieldsInstance->getFields());
+        $this->assertIsObject($fieldsInstance->getFields());
     }
 
     /**
@@ -58,25 +60,22 @@ public function testConstruct2()
 
         $fields = $fieldsInstance->getFields();
 
-        $this->assertInternalType('object', $fields);
+        $this->assertIsObject($fields);
 
         $this->assertObjectHasAttribute(
             Article::getType(),
             $fields
         );
 
-        $this->assertInternalType(
-            'array',
+        $this->assertIsArray(
             $fields->{Article::getType()}
         );
     }
 
-    /**
-     * @covers ::__construct
-     * @expectedException Exception
-     */
-    public function testConstructFailure()
+    public function testConstructFailure(): void
     {
+        $this->expectException(\Exception::class);
+
         new Fields((object)[
             Article::getType() => 'title' //Must be an array
         ]);
@@ -84,10 +83,8 @@ public function testConstructFailure()
 
     /**
      * @covers ::add
-     * @before testGet
-     * @before getFields
      */
-    public function testAdd()
+    public function testAdd(): void
     {
         $return = $this->fields->add(
             Article::getType(),
@@ -106,16 +103,18 @@ public function testAdd()
         );
     }
 
-    /**
-     * @covers ::get
-     */
-    public function testGet()
+    public function testGet(): void
     {
+        $this->fields->add(
+            Article::getType(),
+            ['id', 'title', 'updated']
+        );
+
         $return = $this->fields->get(
             Article::getType()
         );
 
-        $this->assertSame(
+        $this->assertEquals(
             $return,
             ['id', 'title', 'updated']
         );
@@ -124,7 +123,7 @@ public function testGet()
     /**
      * @covers ::get
      */
-    public function testGetForNotSetResourceType()
+    public function testGetForNotSetResourceType(): void
     {
         $return = $this->fields->get(
             Tag::getType()
@@ -136,23 +135,15 @@ public function testGetForNotSetResourceType()
         );
     }
 
-    /**
-     * @covers ::getFields
-     */
-    public function testGetFields()
+    public function testGetFields(): void
     {
-        $fields = $this->fields->getFields();
+        $this->fields->add(Article::getType(), ['id']);
+        $fields = $this->fields->get(Article::getType());
 
-        $this->assertInternalType('object', $fields);
-
-        $this->assertObjectHasAttribute(Article::getType(), $fields);
+        $this->assertNotEmpty($fields);
     }
 
-
-    /**
-     * @covers ::parseFromParameters
-     */
-    public function testParseFromParametersEmpty()
+    public function testParseFromParametersEmpty(): void
     {
         $fields = Fields::parseFromParameters(
             [],
@@ -162,10 +153,7 @@ public function testParseFromParametersEmpty()
         $this->assertNull($fields);
     }
 
-    /**
-     * @covers ::parseFromParameters
-     */
-    public function testParseFromParameters()
+    public function testParseFromParameters(): void
     {
         $parameters = (object) [
             'fields' => [
@@ -188,11 +176,7 @@ public function testParseFromParameters()
         $this->assertEquals(['title'], $fields->fields->{Tag::getType()});
     }
 
-    /**
-     * @covers ::parseFromParameters
-     * @expectedException \Phramework\Exceptions\IncorrectParametersException
-     */
-    public function testParseFromParametersFailureNotAllowed()
+    public function testParseFromParametersFailureNotAllowed(): void
     {
         $parameters = (object)[
             'fields' => [
@@ -200,17 +184,15 @@ public function testParseFromParametersFailureNotAllowed()
             ]
         ];
 
+        $this->expectException(IncorrectParametersException::class);
+
         $fields = Fields::parseFromParameters(
             $parameters,
             Article::class
         );
     }
 
-    /**
-     * @covers ::parseFromParameters
-     * @expectedException \Phramework\Exceptions\IncorrectParametersException
-     */
-    public function testParseFromParametersFailureNotStringValue()
+    public function testParseFromParametersFailureNotStringValue(): void
     {
         $parameters = (object) [
             'fields' => [
@@ -218,17 +200,15 @@ public function testParseFromParametersFailureNotStringValue()
             ]
         ];
 
+        $this->expectException(\Phramework\Exceptions\IncorrectParametersException::class);
+
         Fields::parseFromParameters(
             $parameters,
             Article::class
         );
     }
 
-    /**
-     * @covers ::parseFromParameters
-     * @expectedException \Phramework\Exceptions\RequestException
-     */
-    public function testParseFromParametersFailureNotAllowedResourceType()
+    public function testParseFromParametersFailureNotAllowedResourceType(): void
     {
         $parameters = (object) [
             'fields' => [
@@ -236,6 +216,8 @@ public function testParseFromParametersFailureNotAllowedResourceType()
             ]
         ];
 
+        $this->expectException(\Phramework\Exceptions\RequestException::class);
+
         Fields::parseFromParameters(
             $parameters,
             Article::class
@@ -245,20 +227,22 @@ public function testParseFromParametersFailureNotAllowedResourceType()
     /**
      * @covers ::__get
      */
-    public function testMagicGet()
+    public function testMagicGet(): void
     {
         $fields = new Fields();
 
-        $this->assertInternalType('object', $fields->fields);
+        $this->assertIsObject($fields->fields);
     }
 
     /**
      * @covers ::__get
-     * @expectedException \Exception
      */
-    public function testMagicGetFailure()
-    {
+    public function testMagicGetFailure(): void
+{
         $fields = new Fields();
+
+        $this->expectException(\Exception::class);
+
         $fields->{'not-found'};
     }
 }
diff --git a/tests/src/FilterAttributeTest.php b/tests/src/FilterAttributeTest.php
index 3e00083..1db5c13 100644
--- a/tests/src/FilterAttributeTest.php
+++ b/tests/src/FilterAttributeTest.php
@@ -19,20 +19,21 @@
 use Phramework\Exceptions\RequestException;
 use Phramework\JSONAPI\APP\Models\Article;
 use Phramework\Models\Operator;
+use PHPUnit\Framework\TestCase;
 
 /**
  * @coversDefaultClass Phramework\JSONAPI\FilterAttribute
  * @license https://www.apache.org/licenses/LICENSE-2.0 Apache-2.0
  * @author Xenofon Spafaridis <nohponex@gmail.com>
  */
-class FilterAttributeTest extends \PHPUnit_Framework_TestCase
+class FilterAttributeTest extends TestCase
 {
     /**
      * @var FilterAttribute
      */
     protected $filterAttribute;
 
-    public function setUp()
+    public function setUp(): void
     {
         $this->filterAttribute = new FilterAttribute(
             'id',
@@ -53,7 +54,7 @@ public function getAvailableProperties()
     /**
      * @covers ::__construct
      */
-    public function testConstruct()
+    public function testConstruct(): void
     {
         new FilterAttribute(
             'id',
@@ -65,7 +66,7 @@ public function testConstruct()
     /**
      * @covers ::parse
      */
-    public function testValidate()
+    public function testValidate(): void
     {
         (new FilterTest())->testParseFromParameters();
     }
@@ -74,7 +75,7 @@ public function testValidate()
      * @covers ::parse
      * @expectedException \Phramework\Exceptions\RequestException
      */
-    public function testValidateFailureAttributeArray()
+    public function testValidateFailureAttributeArray(): void
     {
         (new FilterTest())->testParseFromParametersFailureAttributeIsArray();
     }
@@ -83,7 +84,7 @@ public function testValidateFailureAttributeArray()
      * @covers ::parse
      * @expectedException \Phramework\Exceptions\RequestException
      */
-    public function testValidateFailureAttributeJSONSecondLevel()
+    public function testValidateFailureAttributeJSONSecondLevel(): void
     {
         (new FilterTest())->testParseFromParametersFailureAttributeJSONSecondLevel();
     }
@@ -106,7 +107,7 @@ public function testGet($property, $expected)
      * @covers ::__get
      * @expectedException \Exception
      */
-    public function testGetFailure()
+    public function testGetFailure(): void
     {
         $this->filterAttribute->{'not-found'};
     }
diff --git a/tests/src/FilterJSONAttributeTest.php b/tests/src/FilterJSONAttributeTest.php
index c0e3fcd..c193322 100644
--- a/tests/src/FilterJSONAttributeTest.php
+++ b/tests/src/FilterJSONAttributeTest.php
@@ -17,17 +17,18 @@
 namespace Phramework\JSONAPI;
 
 use Phramework\Models\Operator;
+use PHPUnit\Framework\TestCase;
 
 /**
  * @coversDefaultClass Phramework\JSONAPI\FilterJSONAttribute
  * @license https://www.apache.org/licenses/LICENSE-2.0 Apache-2.0
  * @author Xenofon Spafaridis <nohponex@gmail.com>
  */
-class FilterJSONAttributeTest extends \PHPUnit_Framework_TestCase
+class FilterJSONAttributeTest extends TestCase
 {
     protected $filterAttribute;
 
-    public function setUp()
+    public function setUp(): void
     {
         $this->filterAttribute = new FilterJSONAttribute(
             'meta',
@@ -40,7 +41,7 @@ public function setUp()
     /**
      * @covers ::__construct
      */
-    public function testConstruct()
+    public function testConstruct(): void
     {
         new FilterJSONAttribute(
             'meta',
@@ -53,7 +54,7 @@ public function testConstruct()
     /**
      * @covers ::__get
      */
-    public function testGet()
+    public function testGet(): void
     {
         $this->assertSame(
             'keywords',
@@ -65,7 +66,7 @@ public function testGet()
      * @covers ::__get
      * @expectedException \Exception
      */
-    public function testGetFailure()
+    public function testGetFailure(): void
     {
         $this->filterAttribute->{'not-found'};
     }
diff --git a/tests/src/FilterTest.php b/tests/src/FilterTest.php
index c1a0d3f..0e326bf 100644
--- a/tests/src/FilterTest.php
+++ b/tests/src/FilterTest.php
@@ -16,17 +16,20 @@
  */
 namespace Phramework\JSONAPI;
 
+use Phramework\Exceptions\IncorrectParametersException;
+use Phramework\Exceptions\RequestException;
 use Phramework\JSONAPI\APP\Bootstrap;
 use Phramework\JSONAPI\APP\Models\Article;
 use Phramework\JSONAPI\APP\Models\Tag;
 use Phramework\Models\Operator;
+use PHPUnit\Framework\TestCase;
 
 /**
  * @coversDefaultClass Phramework\JSONAPI\Filter
  * @license https://www.apache.org/licenses/LICENSE-2.0 Apache-2.0
  * @author Xenofon Spafaridis <nohponex@gmail.com>
  */
-class FilterTest extends \PHPUnit_Framework_TestCase
+class FilterTest extends TestCase
 {
     public function getAvailableProperties()
     {
@@ -37,48 +40,20 @@ public function getAvailableProperties()
         ];
     }
 
-    /**
-     * @covers ::__construct
-     */
-    public function testConstruct1()
-    {
-        $filter = new Filter(
-            [1, 2, 3],
-            [
-                'tag' => [1, 2]
-            ]
-        );
-    }
-
-    /**
-     * @covers ::__construct
-     */
-    public function testConstruct2()
-    {
-        $filter = new Filter(
-            [1, 2, 3],
-            null
-        );
-    }
-
-    /**
-     * @covers ::__construct
-     * @expectedException Exception
-     */
     public function testConstructFailure1()
     {
+        $this->expectException(\Exception::class);
+
         $filter = new Filter(
             [],
             2
         );
     }
 
-    /**
-     * @covers ::__construct
-     * @expectedException Exception
-     */
     public function testConstructFailure2()
     {
+        $this->expectException(\Exception::class);
+
         $filter = new Filter(
             [],
             (object) [
@@ -87,12 +62,10 @@ public function testConstructFailure2()
         );
     }
 
-    /**
-     * @covers ::__construct
-     * @expectedException Exception
-     */
     public function testConstructFailure3()
     {
+        $this->expectException(\Exception::class);
+
         $filter = new Filter(
             [],
             null,
@@ -105,7 +78,7 @@ public function testConstructFailure3()
     /**
      * @covers ::parseFromParameters
      */
-    public function testParseFromParametersPrimaryUsingIntval()
+    public function testParseFromParametersPrimaryUsingIntval(): void
     {
         $parameters = (object) [
             'filter' => (object) [ //Will accept both arrays and object
@@ -126,7 +99,7 @@ public function testParseFromParametersPrimaryUsingIntval()
     /**
      * @covers ::parseFromParameters
      */
-    public function testParseFromParametersRelationshipEmpty()
+    public function testParseFromParametersRelationshipEmpty(): void
     {
         $parameters = (object) [
             'filter' => (object) [ //Will accept both arrays and object
@@ -147,7 +120,7 @@ public function testParseFromParametersRelationshipEmpty()
     /**
      * @covers ::parseFromParameters
      */
-    public function testParseFromParametersEmpty()
+    public function testParseFromParametersEmpty(): void
     {
         $filter = Filter::parseFromParameters(
             [],
@@ -160,7 +133,7 @@ public function testParseFromParametersEmpty()
     /**
      * @covers ::parseFromParameters
      */
-    public function testParseFromParameters()
+    public function testParseFromParameters(): void
     {
         $parameters = (object) [
             'filter' => [
@@ -190,13 +163,11 @@ public function testParseFromParameters()
             true
         );
 
-        $this->assertInternalType(
-            'object',
+        $this->assertIsObject(
             $filter->relationships
         );
 
-        $this->assertInternalType(
-            'array',
+        $this->assertIsArray(
             $filter->relationships->tag
         );
 
@@ -235,11 +206,7 @@ public function testParseFromParameters()
         $this->assertTrue($found2);
     }
 
-    /**
-     * @covers ::parseFromParameters
-     * @expectedException \Phramework\Exceptions\IncorrectParametersException
-     */
-    public function testParseFromParametersFailurePrimaryNotString()
+    public function testParseFromParametersFailurePrimaryNotString(): void
     {
         $parameters = (object) [
             'filter' => [
@@ -247,18 +214,15 @@ public function testParseFromParametersFailurePrimaryNotString()
             ]
         ];
 
+        $this->expectException(IncorrectParametersException::class);
+
         Filter::parseFromParameters(
             $parameters,
             Article::class //Use article resource model's filters
         );
     }
 
-
-    /**
-     * @covers ::validate
-     * @expectedException \Phramework\Exceptions\IncorrectParametersException
-     */
-    public function testParseFromParametersFailurePrimaryToParse()
+    public function testParseFromParametersFailurePrimaryToParse(): void
     {
         $parameters = (object) [
             'filter' => [
@@ -266,17 +230,15 @@ public function testParseFromParametersFailurePrimaryToParse()
             ]
         ];
 
+        $this->expectException(IncorrectParametersException::class);
+
         Filter::parseFromParameters(
             $parameters,
             Article::class //Use article resource model's filters
         )->validate(Article::class);
     }
 
-    /**
-     * @covers ::parseFromParameters
-     * @expectedException \Phramework\Exceptions\IncorrectParametersException
-     */
-    public function testParseFromParametersFailureRelationshipNotString()
+    public function testParseFromParametersFailureRelationshipNotString(): void
     {
         $parameters = (object) [
             'filter' => [
@@ -284,17 +246,15 @@ public function testParseFromParametersFailureRelationshipNotString()
             ]
         ];
 
+        $this->expectException(IncorrectParametersException::class);
+
         Filter::parseFromParameters(
             $parameters,
             Article::class //Use article resource model's filters
         )->validate(Article::class);
     }
 
-    /**
-     * @covers ::validate
-     * @expectedException \Phramework\Exceptions\RequestException
-     */
-    public function testParseFromParametersFailureNotAllowedAttribute()
+    public function testParseFromParametersFailureNotAllowedAttribute(): void
     {
         $parameters = (object) [
             'filter' => [
@@ -302,17 +262,15 @@ public function testParseFromParametersFailureNotAllowedAttribute()
             ]
         ];
 
+        $this->expectException(RequestException::class);
+
         Filter::parseFromParameters(
             $parameters,
             Article::class //Use article resource model's filters
         )->validate(Article::class);
     }
 
-    /**
-     * @covers ::validate
-     * @expectedException Exception
-     */
-    public function testParseFromParametersFailureAttributeWithoutValidator()
+    public function testParseFromParametersFailureAttributeWithoutValidator(): void
     {
         $parameters = (object) [
             'filter' => [
@@ -320,17 +278,15 @@ public function testParseFromParametersFailureAttributeWithoutValidator()
             ]
         ];
 
+        $this->expectException(\Exception::class);
+
         Filter::parseFromParameters(
             $parameters,
             Article::class //Use article resource model's filters
         )->validate(Article::class);
     }
 
-    /**
-     * @covers ::parseFromParameters
-     * @expectedException \Phramework\Exceptions\RequestException
-     */
-    public function testParseFromParametersFailureAttributeIsArray()
+    public function testParseFromParametersFailureAttributeIsArray(): void
     {
         $parameters = (object) [
             'filter' => [
@@ -338,17 +294,15 @@ public function testParseFromParametersFailureAttributeIsArray()
             ]
         ];
 
+        $this->expectException(RequestException::class);
+
         Filter::parseFromParameters(
             $parameters,
             Article::class //Use article resource model's filters
         );
     }
 
-    /**
-     * @covers ::validate
-     * @expectedException \Phramework\Exceptions\IncorrectParametersException
-     */
-    public function testParseFromParametersFailureAttributeToParse()
+    public function testParseFromParametersFailureAttributeToParse(): void
     {
         $parameters = (object) [
             'filter' => [
@@ -356,17 +310,15 @@ public function testParseFromParametersFailureAttributeToParse()
             ]
         ];
 
+        $this->expectException(IncorrectParametersException::class);
+
         Filter::parseFromParameters(
             $parameters,
             Article::class //Use article resource model's filters
         )->validate(Article::class);
     }
 
-    /**
-     * @covers ::validate
-     * @expectedException \Phramework\Exceptions\RequestException
-     */
-    public function testParseFromParametersFailureAttributeNotAllowedOperator()
+    public function testParseFromParametersFailureAttributeNotAllowedOperator(): void
     {
         $parameters = (object) [
             'filter' => [
@@ -374,17 +326,15 @@ public function testParseFromParametersFailureAttributeNotAllowedOperator()
             ]
         ];
 
+        $this->expectException(RequestException::class);
+
         Filter::parseFromParameters(
             $parameters,
             Article::class //Use article resource model's filters
         )->validate(Article::class);
     }
 
-    /**
-     * @covers ::validate
-     * @expectedException \Phramework\Exceptions\RequestException
-     */
-    public function testParseFromParametersFailureAttributeNotAcceptingJSONOperator()
+    public function testParseFromParametersFailureAttributeNotAcceptingJSONOperator(): void
     {
         $parameters = (object) [
             'filter' => [
@@ -392,17 +342,15 @@ public function testParseFromParametersFailureAttributeNotAcceptingJSONOperator(
             ]
         ];
 
+        $this->expectException(RequestException::class);
+
         Filter::parseFromParameters(
             $parameters,
             Article::class //Use article resource model's filters
         )->validate(Article::class);
     }
 
-    /**
-     * @covers ::validate
-     * @expectedException \Phramework\Exceptions\IncorrectParametersException
-     */
-    public function testParseFromParametersFailureAttributeUsingJSONPropertyValidator()
+    public function testParseFromParametersFailureAttributeUsingJSONPropertyValidator(): void
     {
         $parameters = (object) [
             'filter' => [
@@ -415,14 +363,12 @@ public function testParseFromParametersFailureAttributeUsingJSONPropertyValidato
             Article::class //Use article resource model's filters
         );
 
+        $this->expectException(IncorrectParametersException::class);
+
         $filter->validate(Article::class);
     }
 
-    /**
-     * @covers ::parseFromParameters
-     * @expectedException \Phramework\Exceptions\RequestException
-     */
-    public function testParseFromParametersFailureAttributeJSONSecondLevel()
+    public function testParseFromParametersFailureAttributeJSONSecondLevel(): void
     {
         $parameters = (object) [
             'filter' => [
@@ -430,18 +376,20 @@ public function testParseFromParametersFailureAttributeJSONSecondLevel()
             ]
         ];
 
+        $this->expectException(RequestException::class);
+
         $filter = Filter::parseFromParameters(
             $parameters,
             Article::class //Use article resource model's filters
         );
 
+
+
         $filter->validate(Article::class);
     }
 
-    /**
-     * @covers ::validate
-     */
-    public function testValidate()
+
+    public function testValidate(): void
     {
         $filter = new Filter(
             [],
@@ -451,13 +399,11 @@ public function testValidate()
         );
 
         $filter->validate(Article::class);
+
+        $this->assertTrue(true);
     }
 
-    /**
-     * @covers ::validate
-     * @expectedException \Phramework\Exceptions\RequestException
-     */
-    public function testValidateFailureRelationshipNotFound()
+    public function testValidateFailureRelationshipNotFound(): void
     {
         $filter = new Filter(
             [],
@@ -466,6 +412,8 @@ public function testValidateFailureRelationshipNotFound()
             ]
         );
 
+        $this->expectException(RequestException::class);
+
         $filter->validate(Article::class);
     }
 
@@ -482,14 +430,13 @@ public function testGet($property, $expected)
         $this->assertEquals($expected, $filter->{$property});
     }
 
-    /**
-     * @covers ::__get
-     * @expectedException \Exception
-     */
-    public function testGetFailure()
+    public function testGetFailure(): void
     {
         $filter = new Filter();
 
+
+        $this->expectException(\Exception::class);
+
         $filter->{'not-found'};
     }
 }
diff --git a/tests/src/Model/CacheTest.php b/tests/src/Model/CacheTest.php
index 461d126..4c4f2cc 100644
--- a/tests/src/Model/CacheTest.php
+++ b/tests/src/Model/CacheTest.php
@@ -23,13 +23,14 @@
 use Phramework\JSONAPI\Resource;
 use Phramework\JSONAPI\Viewers\JSONAPI;
 use Phramework\Phramework;
+use PHPUnit\Framework\TestCase;
 
 /**
  * @coversDefaultClass Phramework\JSONAPI\Model\Cache
  * @license https://www.apache.org/licenses/LICENSE-2.0 Apache-2.0
  * @author Xenofon Spafaridis <nohponex@gmail.com>
  */
-class CacheTest extends \PHPUnit_Framework_TestCase
+class CacheTest extends TestCase
 {
     /**
      * Helper method
@@ -50,7 +51,7 @@ protected function get($limit = 1, $offset = 0)
     /**
      * @covers ::initializeCache
      */
-    public function testInitializeCache()
+    public function testInitializeCache(): void
     {
         Bootstrap::invokeStaticMethod(
             Article::class,
@@ -63,7 +64,7 @@ public function testInitializeCache()
      * @covers ::setCache
      * @after testInitializeCache
      */
-    public function testSetCache()
+    public function testSetCache(): void
     {
         $article = clone Article::getById('1');
 
@@ -97,7 +98,7 @@ public function testSetCache()
      * @covers ::getCache
      * @after testInitializeCache
      */
-    public function testGetCache()
+    public function testGetCache(): void
     {
         $this->assertInstanceOf(
             Resource::class,
@@ -119,7 +120,7 @@ public function testGetCache()
      * @covers ::invalidateCache
      * @after testGetCache
      */
-    public function testInvalidateCache()
+    public function testInvalidateCache(): void
     {
         Bootstrap::invokeStaticMethod(
             Article::class,
diff --git a/tests/src/Model/DirectivesTest.php b/tests/src/Model/DirectivesTest.php
index 2bcc1af..bf802c2 100644
--- a/tests/src/Model/DirectivesTest.php
+++ b/tests/src/Model/DirectivesTest.php
@@ -28,18 +28,19 @@
 use Phramework\JSONAPI\Resource;
 use Phramework\JSONAPI\Sort;
 use Phramework\Models\Operator;
+use PHPUnit\Framework\TestCase;
 
 /**
  * @coversDefaultClass Phramework\JSONAPI\Model\Directives
  * @license https://www.apache.org/licenses/LICENSE-2.0 Apache-2.0
  * @author Xenofon Spafaridis <nohponex@gmail.com>
  */
-class DirectivesTest extends \PHPUnit_Framework_TestCase
+class DirectivesTest extends TestCase
 {
     /**
      * @covers ::handleSort
      */
-    public function testHandleSort()
+    public function testHandleSort(): void
     {
         $sort = new Sort(
             Tag::getTable(),
@@ -74,7 +75,7 @@ public function testHandleSort()
     /**
      * @covers ::handleSort
      */
-    public function testHandleSortNull()
+    public function testHandleSortNull(): void
     {
         $sort = new Sort(
             null,
@@ -108,7 +109,7 @@ public function testHandleSortNull()
     /**
      * @covers ::handlePage
      */
-    public function testHandlePage()
+    public function testHandlePage(): void
     {
         $limit  = 1;
         $offset = 2;
@@ -131,7 +132,7 @@ public function testHandlePage()
             $page
         );
 
-        $this->assertInternalType('string', $query);
+        $this->assertIsString($query);
 
         $pattern = sprintf(
             '/^SELECT \* FROM "%s"\s+LIMIT %s\s+OFFSET %s$/',
@@ -146,7 +147,7 @@ public function testHandlePage()
     /**
      * @covers ::handleFields
      */
-    public function testHandleFields()
+    public function testHandleFields(): void
     {
         $additional = 'title';
 
@@ -225,7 +226,7 @@ public function testHandleFields()
      * @covers ::handleGet
      * @todo rewrite
      */
-    public function testHandleGet()
+    public function testHandleGet(): void
     {
         $page = new Page(10, 1);
         $filter = new Filter(
@@ -282,7 +283,7 @@ public function testHandleGet()
     /**
      * @covers ::handleFilter
      */
-    public function testHandleFilterViaGet()
+    public function testHandleFilterViaGet(): void
     {
         $this->testHandleGet();
     }
@@ -290,7 +291,7 @@ public function testHandleFilterViaGet()
     /**
      * @covers ::handleFilter
      */
-    public function testHandleFilter()
+    public function testHandleFilter(): void
     {
         $filter = new Filter();
 
diff --git a/tests/src/Model/GetTest.php b/tests/src/Model/GetTest.php
index d960d2d..bb0539f 100644
--- a/tests/src/Model/GetTest.php
+++ b/tests/src/Model/GetTest.php
@@ -21,6 +21,7 @@
 use Phramework\JSONAPI\Page;
 use Phramework\JSONAPI\Resource;
 use Phramework\JSONAPI\Sort;
+use PHPUnit\Framework\TestCase;
 
 /**
  * @coversDefaultClass Phramework\JSONAPI\Model\Get
@@ -28,7 +29,7 @@
  * @author Xenofon Spafaridis <nohponex@gmail.com>
  * @afterClass CacheTest
  */
-class GetTest extends \PHPUnit_Framework_TestCase
+class GetTest extends TestCase
 {
     /**
      * Helper method
@@ -50,7 +51,7 @@ protected function get($limit = 1, $offset = 0)
      * @covers ::get
      * @expectedException \Phramework\Exceptions\NotImplementedException
      */
-    public function testGet()
+    public function testGet(): void
     {
         Get::get();
     }
@@ -61,8 +62,8 @@ public function testGet()
      * Assuming at least one trend_template exists
      * @covers ::getById
      */
-    public function testGetById()
-    {
+    public function testGetById(): string
+{
         //Get 2 first items
         $collection = self::get(2);
 
@@ -73,7 +74,7 @@ public function testGetById()
         //Request again to access cached
         $collectionResource = Article::getById($id);
 
-        $this->assertInternalType('object', $collectionResource);
+        $this->assertIsObject($collectionResource);
         $this->assertSame($id, $collectionResource->id);
         $this->assertSame(Article::getType(), $collectionResource->type);
 
@@ -90,7 +91,7 @@ public function testGetById()
         //Request again to access cached
         $resources = Article::getById($ids);
 
-        $this->assertInternalType('object', $resources);
+        $this->assertIsObject($resources);
 
         $resourcesCount = 0;
         foreach ($resources as $r) {
@@ -109,7 +110,7 @@ public function testGetById()
 
             $resource = $resources->{$resourceId};
 
-            $this->assertInternalType('object', $resource);
+            $this->assertIsObject($resource);
             $this->assertSame($resourceId, $resource->id);
             $this->assertSame(Article::getType(), $resource->type);
         }
@@ -127,7 +128,7 @@ public function testGetById()
         //Fetch multiple resources
         $resources = Article::getById($ids);
 
-        $this->assertInternalType('object', $resources);
+        $this->assertIsObject($resources);
 
         $resourcesCount = 0;
         foreach ($resources as $r) {
@@ -147,7 +148,7 @@ public function testGetById()
         $resourceId = $ids[0];
         $resource = $resources->{$resourceId};
 
-        $this->assertInternalType('object', $resource);
+        $this->assertIsObject($resource);
         $this->assertSame($resourceId, $resource->id);
         $this->assertSame(Article::getType(), $resource->type);
 
@@ -167,7 +168,7 @@ public function testGetById()
     /**
      * @covers ::parseSort
      */
-    public function testParseSort()
+    public function testParseSort(): void
     {
        $this->assertInstanceOf(Sort::class, Article::parseSort((object) []));
     }
@@ -175,7 +176,7 @@ public function testParseSort()
     /**
      * @covers ::parsePage
      */
-    public function testParsePage()
+    public function testParsePage(): void
     {
         $this->assertNull(Article::parsePage((object) []));
     }
@@ -183,7 +184,7 @@ public function testParsePage()
     /**
      * @covers ::parseFields
      */
-    public function testParseFields()
+    public function testParseFields(): void
     {
         $this->assertNull(Article::parseFields((object) []));
     }
@@ -191,7 +192,7 @@ public function testParseFields()
     /**
      * @covers ::parseFilter
      */
-    public function testParseFilter()
+    public function testParseFilter(): void
     {
         $this->assertNull(Article::parseFilter((object) []));
     }
diff --git a/tests/src/Model/RelationshipTest.php b/tests/src/Model/RelationshipTest.php
index 282a968..51e1591 100644
--- a/tests/src/Model/RelationshipTest.php
+++ b/tests/src/Model/RelationshipTest.php
@@ -19,18 +19,19 @@
 use Phramework\JSONAPI\APP\Models\Article;
 use Phramework\JSONAPI\APP\Models\Tag;
 use Phramework\JSONAPI\Page;
+use PHPUnit\Framework\TestCase;
 
 /**
  * @coversDefaultClass Phramework\JSONAPI\Model\Relationship
  * @license https://www.apache.org/licenses/LICENSE-2.0 Apache-2.0
  * @author Xenofon Spafaridis <nohponex@gmail.com>
  */
-class RelationshipTest extends \PHPUnit_Framework_TestCase
+class RelationshipTest extends TestCase
 {
     /**
      * @covers ::getRelationshipData
      */
-    public function testGetRelationshipData()
+    public function testGetRelationshipData(): void
     {
         $articles = Article::get(new Page(1, 1))[0];
 
diff --git a/tests/src/ModelTest.php b/tests/src/ModelTest.php
index 6fd1797..6847f27 100644
--- a/tests/src/ModelTest.php
+++ b/tests/src/ModelTest.php
@@ -21,13 +21,14 @@
 use Phramework\JSONAPI\APP\Models\Article;
 use Phramework\Util\Util;
 use Phramework\Validate\ObjectValidator;
+use PHPUnit\Framework\TestCase;
 
 /**
  * @coversDefaultClass Phramework\JSONAPI\Model
  * @license https://www.apache.org/licenses/LICENSE-2.0 Apache-2.0
  * @author Xenofon Spafaridis <nohponex@gmail.com>
  */
-class ModelTest extends \PHPUnit_Framework_TestCase
+class ModelTest extends TestCase
 {
     /**
      * @covers ::getValidationModel
@@ -57,8 +58,8 @@ public function testFilterValidationModel($modelClass)
     /**
      * @covers ::collection
      */
-    public function testCollection()
-    {
+    public function testCollection(): void
+{
         $resources = Article::collection([
             [
                 'id' => 1
@@ -72,8 +73,8 @@ public function testCollection()
     /**
      * @covers ::resource
      */
-    public function testResource()
-    {
+    public function testResource(): void
+{
         $resources = Article::resource(
             [
                 'id' => 1
@@ -92,7 +93,7 @@ public function testGetFilterable($modelClass)
     {
         $fields = $modelClass::getFilterable();
 
-        $this->assertInternalType('object', $fields);
+        $this->assertIsObject($fields);
 
         $this->assertTrue(Util::isArrayOf((array)$fields, 'integer'), 'Expect object of integers');
     }
@@ -138,8 +139,8 @@ public function testGetFields($modelClass)
     /**
      * @covers ::getSort
      */
-    public function testGetSort()
-    {
+    public function testGetSort(): void
+{
         $sort = Article::getSort();
 
         $this->assertInstanceOf(Sort::class, $sort);
diff --git a/tests/src/PageTest.php b/tests/src/PageTest.php
index f5f9573..ad78982 100644
--- a/tests/src/PageTest.php
+++ b/tests/src/PageTest.php
@@ -17,13 +17,14 @@
 namespace Phramework\JSONAPI;
 
 use Phramework\JSONAPI\APP\Models\Article;
+use PHPUnit\Framework\TestCase;
 
 /**
  * @coversDefaultClass Phramework\JSONAPI\Page
  * @license https://www.apache.org/licenses/LICENSE-2.0 Apache-2.0
  * @author Xenofon Spafaridis <nohponex@gmail.com>
  */
-class PageTest extends \PHPUnit_Framework_TestCase
+class PageTest extends TestCase
 {
     public function getAvailableProperties()
     {
@@ -36,7 +37,7 @@ public function getAvailableProperties()
     /**
      * @covers ::__construct
      */
-    public function testConstruct()
+    public function testConstruct(): void
     {
         $page = new Page();
     }
@@ -44,7 +45,7 @@ public function testConstruct()
     /**
      * @covers ::parseFromParameters
      */
-    public function testParseFromParametersEmpty()
+    public function testParseFromParametersEmpty(): void
     {
         $page = Page::parseFromParameters(
             [],
@@ -57,7 +58,7 @@ public function testParseFromParametersEmpty()
     /**
      * @covers ::parseFromParameters
      */
-    public function testParseFromParameters()
+    public function testParseFromParameters(): void
     {
         $parameters = (object) [
             'page' => [
@@ -84,7 +85,7 @@ public function testParseFromParameters()
      * @covers ::parseFromParameters
      * @expectedException \Phramework\Exceptions\IncorrectParametersException
      */
-    public function testParseFromParametersFailureToParseLimit()
+    public function testParseFromParametersFailureToParseLimit(): void
     {
         $parameters = (object) [
             'page' => (object) [
@@ -102,7 +103,7 @@ public function testParseFromParametersFailureToParseLimit()
      * @covers ::parseFromParameters
      * @expectedException \Phramework\Exceptions\IncorrectParametersException
      */
-    public function testParseFromParametersFailureToParseOffset()
+    public function testParseFromParametersFailureToParseOffset(): void
     {
         $parameters = (object) [
             'page' => [
@@ -133,7 +134,7 @@ public function testGet($property, $expected)
      * @covers ::__get
      * @expectedException \Exception
      */
-    public function testGetFailure()
+    public function testGetFailure(): void
     {
         $page = new Page();
 
diff --git a/tests/src/RelationshipTest.php b/tests/src/RelationshipTest.php
index 528db1f..488daa5 100644
--- a/tests/src/RelationshipTest.php
+++ b/tests/src/RelationshipTest.php
@@ -19,13 +19,14 @@
 use Phramework\JSONAPI\APP\Models\Tag;
 use Phramework\JSONAPI\Relationship;
 use Phramework\Phramework;
+use PHPUnit\Framework\TestCase;
 
 /**
  * @coversDefaultClass \Phramework\JSONAPI\Relationship
  * @license https://www.apache.org/licenses/LICENSE-2.0 Apache-2.0
  * @author Xenofon Spafaridis <nohponex@gmail.com>
  */
-class RelationshipTest extends \PHPUnit_Framework_TestCase
+class RelationshipTest extends TestCase
 {
     public function getAvailableProperties()
     {
@@ -43,7 +44,7 @@ public function getAvailableProperties()
      */
     protected $relationship;
 
-    public function setUp()
+    public function setUp(): void
     {
         $this->relationship = new Relationship(
             Tag::class
@@ -53,7 +54,7 @@ public function setUp()
     /**
      * @covers ::__construct
      */
-    public function testConstruct()
+    public function testConstruct(): void
     {
         new Relationship(
             Tag::class,
@@ -121,7 +122,7 @@ public function testConstructFailure2()
      * @covers ::__construct
      * @expectedException \Exception
      */
-    public function testConstructFailureInvalidCallbackMethod()
+    public function testConstructFailureInvalidCallbackMethod(): void
     {
         new Relationship(
             Tag::class,
@@ -137,7 +138,7 @@ public function testConstructFailureInvalidCallbackMethod()
      * @covers ::__construct
      * @expectedException \Exception
      */
-    public function testConstructFailureInvalidMethodNotCallable()
+    public function testConstructFailureInvalidMethodNotCallable(): void
     {
         new Relationship(
             Tag::class,
@@ -164,7 +165,7 @@ public function testGet($property, $expected)
      * @covers ::__get
      * @expectedException \Exception
      */
-    public function testGetFailure()
+    public function testGetFailure(): void
     {
         $this->relationship->{'not-found'};
     }
@@ -172,7 +173,7 @@ public function testGetFailure()
     /**
      * @covers ::__set
      */
-    public function testSet()
+    public function testSet(): void
     {
         $this->relationship->{'flags'} = Relationship::FLAG_INCLUDE_BY_DEFAULT;
 
@@ -183,7 +184,7 @@ public function testSet()
      * @covers ::__set
      * @expectedException \Exception
      */
-    public function testSetFailure()
+    public function testSetFailure(): void
     {
         $this->relationship->{'modelClass'} = Tag::class;
     }
diff --git a/tests/src/ResourceTest.php b/tests/src/ResourceTest.php
index ba2357d..0a79867 100644
--- a/tests/src/ResourceTest.php
+++ b/tests/src/ResourceTest.php
@@ -19,13 +19,14 @@
 use Phramework\JSONAPI\APP\Models\Article;
 use Phramework\JSONAPI\APP\Models\Tag;
 use Phramework\JSONAPI\APP\Models\User;
+use PHPUnit\Framework\TestCase;
 
 /**
  * @coversDefaultClass Phramework\JSONAPI\Resource
  * @license https://www.apache.org/licenses/LICENSE-2.0 Apache-2.0
  * @author Xenofon Spafaridis <nohponex@gmail.com>
  */
-class ResourceTest extends \PHPUnit_Framework_TestCase
+class ResourceTest extends TestCase
 {
     public function getAvailableProperties()
     {
@@ -42,7 +43,7 @@ public function getAvailableProperties()
     /**
      * @covers ::__construct
      */
-    public function testConstruct()
+    public function testConstruct(): void
     {
         new Resource(
             Article::getType(),
@@ -53,7 +54,7 @@ public function testConstruct()
     /**
      * @covers ::parseFromRecords
      */
-    public function testParseFromRecords()
+    public function testParseFromRecords(): void
     {
         $articles = Article::get();
     }
@@ -61,7 +62,7 @@ public function testParseFromRecords()
     /**
      * @covers ::parseFromRecord
      */
-    public function testParseFromRecord()
+    public function testParseFromRecord(): void
     {
         $tags = Tag::get();
 
@@ -71,7 +72,7 @@ public function testParseFromRecord()
     /**
      * @covers ::parseFromRecords
      */
-    public function testParseFromRecordsEmpty()
+    public function testParseFromRecordsEmpty(): void
     {
         $this->assertEmpty(Tag::collection(null));
         $this->assertEmpty(Tag::collection([]));
@@ -80,7 +81,7 @@ public function testParseFromRecordsEmpty()
     /**
      * @covers ::parseFromRecord
      */
-    public function testParseFromRecordEmpty()
+    public function testParseFromRecordEmpty(): void
     {
         $this->assertNull(Tag::resource(null));
         $this->assertNull(Tag::resource([]));
@@ -90,7 +91,7 @@ public function testParseFromRecordEmpty()
      * @covers ::parseFromRecord
      * @expectedException \Exception
      */
-    public function testParseFromRecordFailureModelClass()
+    public function testParseFromRecordFailureModelClass(): void
     {
         Resource::parseFromRecord(
             [
@@ -103,7 +104,7 @@ public function testParseFromRecordFailureModelClass()
     /**
      * @covers ::parseFromRecord
      */
-    public function testParseFromRecordSuccessToOnePreloaded()
+    public function testParseFromRecordSuccessToOnePreloaded(): void
     {
         Article::resource([
             'id' => '1',
@@ -114,7 +115,7 @@ public function testParseFromRecordSuccessToOnePreloaded()
     /**
      * @covers ::parseFromRecord
      */
-    public function testParseFromRecordSuccessToOnePreloadedRelationshipResource()
+    public function testParseFromRecordSuccessToOnePreloadedRelationshipResource(): void
     {
         $creator = RelationshipResource::parseFromRecord(User::$records[0], User::class);
 
@@ -128,7 +129,7 @@ public function testParseFromRecordSuccessToOnePreloadedRelationshipResource()
      * @covers ::parseFromRecord
      * @expectedException \Exception
      */
-    public function testParseFromRecordSuccessToOnePreloadedResource()
+    public function testParseFromRecordSuccessToOnePreloadedResource(): void
     {
         $creator = User::resource(User::$records[0]);
 
@@ -141,7 +142,7 @@ public function testParseFromRecordSuccessToOnePreloadedResource()
     /**
      * @covers ::parseFromRecord
      */
-    public function testParseFromRecordSuccessToOneUseCallback()
+    public function testParseFromRecordSuccessToOneUseCallback(): void
     {
         Article::resource([
             'id' => '1'
@@ -151,7 +152,7 @@ public function testParseFromRecordSuccessToOneUseCallback()
     /**
      * @covers ::parseFromRecord
      */
-    public function testParseFromRecordSuccessToManyPreloaded()
+    public function testParseFromRecordSuccessToManyPreloaded(): void
     {
         Article::resource([
             'id' => '1',
@@ -163,7 +164,7 @@ public function testParseFromRecordSuccessToManyPreloaded()
      * @covers ::parseFromRecord
      * @expectedException \Exception
      */
-    public function testParseFromRecordFailureNoIdAttributeSetInRecord()
+    public function testParseFromRecordFailureNoIdAttributeSetInRecord(): void
     {
         Tag::resource(['title' => 'true']);
     }
@@ -172,7 +173,7 @@ public function testParseFromRecordFailureNoIdAttributeSetInRecord()
      * @covers ::parseFromRecord
      * @expectedException \Exception
      */
-    public function testParseFromRecordFailureMetaNotAnObject()
+    public function testParseFromRecordFailureMetaNotAnObject(): void
     {
         Tag::resource([
             'id' => '1',
@@ -196,7 +197,7 @@ public function testParseFromRecordFailureMetaNotAnObject2()
      * @covers ::parseFromRecord
      * @expectedException \Exception
      */
-    public function testParseFromRecordFailureToManyNotAnStringOrResource()
+    public function testParseFromRecordFailureToManyNotAnStringOrResource(): void
     {
         Article::resource([
             'id' => '1',
@@ -208,7 +209,7 @@ public function testParseFromRecordFailureToManyNotAnStringOrResource()
      * @covers ::parseFromRecord
      * @expectedException \Exception
      */
-    public function testParseFromRecordFailureToManyNotAnArray()
+    public function testParseFromRecordFailureToManyNotAnArray(): void
     {
         $this->markTestIncomplete();
         Article::resource([
@@ -221,7 +222,7 @@ public function testParseFromRecordFailureToManyNotAnArray()
      * @covers ::parseFromRecord
      * @expectedException \Exception
      */
-    public function testParseFromRecordFailureToManyNotAnArrayOfStringsOrAttributes()
+    public function testParseFromRecordFailureToManyNotAnArrayOfStringsOrAttributes(): void
     {
         $this->markTestIncomplete();
         Article::resource([
@@ -255,7 +256,7 @@ public function testSet($property)
     /**
      * @covers ::__set
      */
-    public function testSetId()
+    public function testSetId(): void
     {
         $resource = new Resource(Tag::getType(), '1');
 
@@ -294,7 +295,7 @@ public function testGet($property, $expected)
      * @covers ::__get
      * @expectedException \Exception
      */
-    public function testGetFailure()
+    public function testGetFailure(): void
     {
         $resource = new Resource(Tag::getType(), '1');
 
diff --git a/tests/src/SortTest.php b/tests/src/SortTest.php
index 3639a23..a0744f0 100644
--- a/tests/src/SortTest.php
+++ b/tests/src/SortTest.php
@@ -16,15 +16,17 @@
  */
 namespace Phramework\JSONAPI;
 
+use Phramework\Exceptions\RequestException;
 use Phramework\JSONAPI\APP\Models\Article;
 use Phramework\JSONAPI\APP\Models\Tag;
+use PHPUnit\Framework\TestCase;
 
 /**
  * @coversDefaultClass Phramework\JSONAPI\Sort
  * @license https://www.apache.org/licenses/LICENSE-2.0 Apache-2.0
  * @author Xenofon Spafaridis <nohponex@gmail.com>
  */
-class SortTest extends \PHPUnit_Framework_TestCase
+class SortTest extends TestCase
 {
     public function getAvailableProperties()
     {
@@ -38,7 +40,7 @@ public function getAvailableProperties()
     /**
      * @covers ::__construct
      */
-    public function testConstruct()
+    public function testConstruct(): void
     {
         $sort = new Sort(
             Article::getTable(),
@@ -49,7 +51,7 @@ public function testConstruct()
     /**
      * @covers ::parseFromParameters
      */
-    public function testParseFromParametersEmpty()
+    public function testParseFromParametersEmpty(): void
     {
         $sort = Sort::parseFromParameters(
             [],
@@ -62,7 +64,7 @@ public function testParseFromParametersEmpty()
     /**
      * @covers ::parseFromParameters
      */
-    public function testParseFromParameters()
+    public function testParseFromParameters(): void
     {
         $parameters = (object) [
             'sort' => '-id'
@@ -96,64 +98,57 @@ public function testParseFromParameters()
         $this->assertTrue($sort->ascending);
     }
 
-    /**
-     * @covers ::parseFromParameters
-     * @expectedException \Phramework\Exceptions\RequestException
-     */
-    public function testParseFromParametersFailureNotString()
+    public function testParseFromParametersFailureNotString(): void
     {
         $parameters = (object) [
             'sort' => ['id']
         ];
 
+        $this->expectException(RequestException::class);
+
         $sort = Sort::parseFromParameters(
             $parameters,
             Article::class
         );
     }
 
-    /**
-     * @covers ::parseFromParameters
-     * @expectedException \Phramework\Exceptions\RequestException
-     */
-    public function testParseFromParametersFailureParseExpression()
+    public function testParseFromParametersFailureParseExpression(): void
     {
         $parameters = (object) [
             'sort' => '--id'
         ];
 
+        $this->expectException(RequestException::class);
+
         $sort = Sort::parseFromParameters(
             $parameters,
             Article::class
         );
     }
 
-    /**
-     * @covers ::parseFromParameters
-     * @expectedException \Phramework\Exceptions\RequestException
-     */
-    public function testParseFromParametersFailureNotSortable()
+    public function testParseFromParametersFailureNotSortable(): void
     {
         $parameters = (object) [
             'sort' => 'meta'
         ];
 
+        $this->expectException(RequestException::class);
+
         $sort = Sort::parseFromParameters(
             $parameters,
             Article::class
         );
     }
 
-    /**
-     * @covers ::parseFromParameters
-     * @expectedException \Phramework\Exceptions\RequestException
-     */
-    public function testParseFromParametersFailureNoSortableAttributes()
+    public function testParseFromParametersFailureNoSortableAttributes(): void
     {
         $parameters = (object) [
             'sort' => 'id'
         ];
 
+
+        $this->expectException(RequestException::class);
+
         $sort = Sort::parseFromParameters(
             $parameters,
             Tag::class
@@ -180,7 +175,7 @@ public function testGet($property, $expected)
      * @covers ::__get
      * @expectedException \Exception
      */
-    public function testGetFailure()
+    public function testGetFailure(): void
     {
         $sort = new Sort(
             Article::getTable(),
diff --git a/tests/src/ValidationModelTest.php b/tests/src/ValidationModelTest.php
index df029bc..ce6d933 100644
--- a/tests/src/ValidationModelTest.php
+++ b/tests/src/ValidationModelTest.php
@@ -17,18 +17,19 @@
 namespace Phramework\JSONAPI;
 
 use Phramework\Validate\ObjectValidator;
+use PHPUnit\Framework\TestCase;
 
 /**
  * @coversDefaultClass Phramework\JSONAPI\ValidationModel
  * @license https://www.apache.org/licenses/LICENSE-2.0 Apache-2.0
  * @author Xenofon Spafaridis <nohponex@gmail.com>
  */
-class ValidationModelTest extends \PHPUnit_Framework_TestCase
+class ValidationModelTest extends TestCase
 {
     /**
      * @covers ::__construct
      */
-    public function testConstruct()
+    public function testConstruct(): void
     {
         new ValidationModel(
             new ObjectValidator(),
diff --git a/tests/src/Viewers/JSONAPITest.php b/tests/src/Viewers/JSONAPITest.php
index 592e6f5..ef3a581 100644
--- a/tests/src/Viewers/JSONAPITest.php
+++ b/tests/src/Viewers/JSONAPITest.php
@@ -19,18 +19,19 @@
 use Phramework\JSONAPI\APP\Models\Article;
 use Phramework\JSONAPI\APP\Models\Tag;
 use Phramework\JSONAPI\Relationship;
+use PHPUnit\Framework\TestCase;
 
 /**
  * @coversDefaultClass \Phramework\JSONAPI\Viewers\JSONAPI
  * @license https://www.apache.org/licenses/LICENSE-2.0 Apache-2.0
  * @author Xenofon Spafaridis <nohponex@gmail.com>
  */
-class JSONAPITest extends \PHPUnit_Framework_TestCase
+class JSONAPITest extends TestCase
 {
     /**
      * @covers ::view
      */
-    public function testView()
+    public function testView(): void
     {
         ob_start();
         (new JSONAPI())->view((object) [
@@ -53,7 +54,7 @@ public function testView()
      * @covers ::header
      * @before testView
      */
-    public function testHeader()
+    public function testHeader(): void
     {
         JSONAPI::header();
     }