Add a validator interface, UpperRangeValidator and OkValidator.

tests/Unit/Validation/Validators/OkValidatorTest.php

@@ -0,0 +1,17 @@
+<?php
+
+namespace Tests\Unit;
+
+use PHPUnit\Framework\TestCase;
+
+use App\Models\Validation\Validators\OkValidator;
+
+class OkValidatorTest extends TestCase
+{
+    public function testIsValid(): void
+    {
+        $validator = new OkValidator();
+
+        $this->assertTrue($validator->isValid());
+    }
+}

tests/Unit/Validation/Validators/UpperRangeValidatorTest.php

@@ -0,0 +1,51 @@
+<?php
+
+namespace Tests\Unit;
+
+use PHPUnit\Framework\TestCase;
+
+use App\Models\Validation\Validators\UpperRangeValidator;
+use App\Models\Validation\Validators\OkValidator;
+
+class UpperRangeValidatorTest extends TestCase
+{
+    public function dataProvider() {
+        return [
+            'Valid Case for 10' => [
+                'value' => 10,
+                'limit' => 10,
+                'isValid' => true,
+            ],
+            'Valid Case for 255' => [
+                'value' => 0,
+                'limit' => 255,
+                'isValid' => true,
+            ],
+            'Invalid Case for 255' => [
+                'value' => 11,
+                'limit' => 10,
+                'isValid' => false,
+            ],
+            'Invalid Case for 255' => [
+                'value' => 256,
+                'limit' => 255,
+                'isValid' => false,
+            ],
+        ];
+    }
+
+    public function setUpValidator(int $value, int $rangeLimit): UpperRangeValidator
+    {
+        return new UpperRangeValidator($value, $rangeLimit, new OkValidator());
+    }
+
+    /**
+     * @dataProvider dataProvider
+     */
+    public function testGetMessage(int $value, int $limit, bool $isValid): void
+    {
+        $validator = $this->setUpValidator($value, $limit);
+
+        $this->assertEquals($validator->isValid(), $isValid);
+    }
+}