test(core): add unit tests for global helper functions

Tests cover e(), money(), percentage(), arabic_date(), age_from_dob(), now(), and today() helpers.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

tests/Unit/Core/HelpersTest.php

+<?php
+declare(strict_types=1);
+
+namespace Tests\Unit\Core;
+
+use Tests\TestCase;
+
+class HelpersTest extends TestCase
+{
+    public function testEscapesHtml(): void
+    {
+        $this->assertSame('&lt;script&gt;alert(&quot;xss&quot;)&lt;/script&gt;', e('<script>alert("xss")</script>'));
+    }
+
+    public function testEscapesQuotes(): void
+    {
+        $this->assertSame('it&#039;s &amp; &quot;quoted&quot;', e('it\'s & "quoted"'));
+    }
+
+    public function testEscapesNull(): void
+    {
+        $this->assertSame('', e(null));
+    }
+
+    public function testMoneyFormatsCorrectly(): void
+    {
+        $this->assertSame('1,000.50 ج.م', money(1000.5));
+    }
+
+    public function testMoneyFormatsZero(): void
+    {
+        $this->assertSame('0.00 ج.م', money(0));
+    }
+
+    public function testMoneyFormatsNegative(): void
+    {
+        $this->assertSame('-500.00 ج.م', money(-500));
+    }
+
+    public function testMoneyWithCustomCurrency(): void
+    {
+        $this->assertSame('100.00 $', money(100, '$'));
+    }
+
+    public function testMoneyHandlesStringInput(): void
+    {
+        $this->assertSame('250.75 ج.م', money('250.75'));
+    }
+
+    public function testMoneyHandlesNonNumericInput(): void
+    {
+        $this->assertSame('0.00 ج.م', money('abc'));
+    }
+
+    public function testPercentageFormats(): void
+    {
+        $this->assertSame('75.50%', percentage(75.5));
+    }
+
+    public function testPercentageZero(): void
+    {
+        $this->assertSame('0.00%', percentage(0));
+    }
+
+    public function testPercentageFromString(): void
+    {
+        $this->assertSame('33.33%', percentage('33.33'));
+    }
+
+    public function testArabicDateFormatsCorrectly(): void
+    {
+        $result = arabic_date('2024-01-15');
+        $this->assertStringContainsString('يناير', $result);
+        $this->assertStringContainsString('2024', $result);
+        $this->assertStringContainsString('15', $result);
+    }
+
+    public function testArabicDateDecemberFormat(): void
+    {
+        $result = arabic_date('2024-12-25');
+        $this->assertStringContainsString('ديسمبر', $result);
+        $this->assertStringContainsString('25', $result);
+    }
+
+    public function testArabicDateReturnsOriginalOnInvalid(): void
+    {
+        $this->assertSame('not-a-date', arabic_date('not-a-date'));
+    }
+
+    public function testAgeFromDobReturnsArray(): void
+    {
+        $result = age_from_dob('2000-01-01');
+        $this->assertArrayHasKey('years', $result);
+        $this->assertArrayHasKey('months', $result);
+        $this->assertArrayHasKey('days', $result);
+        $this->assertArrayHasKey('total_months', $result);
+        $this->assertGreaterThan(20, $result['years']);
+    }
+
+    public function testAgeFromDobInvalidDate(): void
+    {
+        $result = age_from_dob('invalid');
+        $this->assertSame(0, $result['years']);
+        $this->assertSame(0, $result['months']);
+        $this->assertSame(0, $result['days']);
+        $this->assertSame(0, $result['total_months']);
+    }
+
+    public function testNowReturnsDateTimeFormat(): void
+    {
+        $result = now();
+        $this->assertMatchesRegularExpression('/^\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}$/', $result);
+    }
+
+    public function testTodayReturnsDateFormat(): void
+    {
+        $result = today();
+        $this->assertMatchesRegularExpression('/^\d{4}-\d{2}-\d{2}$/', $result);
+        $this->assertSame(date('Y-m-d'), $result);
+    }
+}