feat: Implement entity "check"

src/Domain/Entities/Check.php

@@ -0,0 +1,50 @@
+<?php
+
+declare(strict_types=1);
+
+namespace RPGPlayground\Domain\Entities;
+
+final class Check
+{
+    private function __construct(
+        public readonly string $title,
+        public readonly int $threshold,
+    ) {}
+
+    /**
+     * @param string $title
+     * @param int $threshold
+     * @return self
+     * @throws \InvalidArgumentException
+     */
+    public static function create(string $title, int $threshold): self
+    {
+        if (empty($title)) {
+            throw new \InvalidArgumentException('Title cannot be empty.');
+        }
+
+        if ($threshold < 0) {
+            throw new \InvalidArgumentException('Threshold must be greater than or equal to 0.');
+        }
+
+        return new self($title, $threshold);
+    }
+
+    /**
+     * @param int $roll
+     * @return bool
+     */
+    public function isSuccess(int $roll): bool
+    {
+        return $roll >= $this->threshold;
+    }
+
+    /**
+     * @param int $roll
+     * @return bool
+     */
+    public function isFailure(int $roll): bool
+    {
+        return $roll < $this->threshold;
+    }
+}

src/Domain/ValueObjects/Dice.php

@@ -13,7 +13,7 @@ final class Dice
      * @throws \InvalidArgumentException
      */
     public function __construct(
-        public int $sides,
+        public readonly int $sides,
     ) {
         if ($sides < self::MINIMUM_VALUE) {
             throw new \InvalidArgumentException('Invalid number of sides for a dice');

tests/Domain/Entities/CheckTest.php

@@ -0,0 +1,59 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Tests\Domain\Entities;
+
+use PHPUnit\Framework\TestCase;
+use RPGPlayground\Domain\Entities\Check;
+
+final class CheckTest extends TestCase
+{
+    // -------------------------------------------------------------------------
+    // Happy path
+    // -------------------------------------------------------------------------
+
+    public function test_check_is_created_with_valid_data(): void
+    {
+        $check = Check::create('My Check', 10);
+
+        $this->assertSame('My Check', $check->title);
+        $this->assertSame(10, $check->threshold);
+    }
+
+    public function test_check_is_successful_when_roll_is_greater_than_or_equal_to_threshold(): void
+    {
+        $check = Check::create('My Check', 10);
+
+        $this->assertTrue($check->isSuccess(10));
+        $this->assertFalse($check->isSuccess(9));
+    }
+
+    public function test_check_is_failure_when_roll_is_less_than_threshold(): void
+    {
+        $check = Check::create('My Check', 10);
+
+        $this->assertFalse($check->isFailure(10));
+        $this->assertTrue($check->isFailure(9));
+    }
+
+    // -------------------------------------------------------------------------
+    // Exceptions
+    // -------------------------------------------------------------------------
+
+    public function test_check_throws_exception_when_threshold_is_negative(): void
+    {
+        $this->expectException(\InvalidArgumentException::class);
+        $this->expectExceptionMessage('Threshold must be greater than or equal to 0.');
+
+        Check::create('My Check', -1);
+    }
+
+    public function test_check_throws_exception_when_title_is_empty(): void
+    {
+        $this->expectException(\InvalidArgumentException::class);
+        $this->expectExceptionMessage('Title cannot be empty.');
+
+        Check::create('', 10);
+    }
+}