Added the GTIN validator (standalone) and Laravel Validation rule cla…

…sses

Changelog.md

@@ -9,6 +9,7 @@
 - Changed the minimum Laravel 10 version to v10.48
 - Added Laravel 12 Support
 - PHP 8.4 deprecation fixes
+- Added the GTIN validator (standalone) and Laravel Validation rule classes
 
 ## 4.x Series
 

Tests/GtinValidationRuleTest.php

@@ -0,0 +1,89 @@
+<?php
+
+declare(strict_types=1);
+
+use Illuminate\Translation\ArrayLoader;
+use Illuminate\Translation\Translator;
+use Illuminate\Validation\Validator;
+use PHPUnit\Framework\TestCase;
+use Vanilo\Support\Validation\Rules\MustBeAValidGtin;
+
+class GtinValidationRuleTest extends TestCase
+{
+    private $translator;
+
+    protected function setUp(): void
+    {
+        parent::setUp();
+
+        $this->translator = new Translator(new ArrayLoader(), 'en_US');
+        app()->instance('translator', $this->translator);
+    }
+
+    /** @test */
+    public function it_accepts_a_valid_gtin()
+    {
+        $validator = new Validator(
+            $this->translator,
+            ['gtin' => '1300000000000'],
+            ['gtin' => [new MustBeAValidGtin()]]
+        );
+
+        $this->assertTrue($validator->passes());
+    }
+
+    /** @test */
+    public function it_rejects_an_invalid_gtin()
+    {
+        $validator = new Validator(
+            $this->translator,
+            ['gtin' => '1300000000001'],
+            ['gtin' => [new MustBeAValidGtin()]]
+        );
+
+        $this->assertFalse($validator->passes());
+    }
+
+    /** @test */
+    public function it_rejects_an_array_as_field_value()
+    {
+        $validator = new Validator(
+            $this->translator,
+            ['gtin' => []],
+            ['gtin' => [new MustBeAValidGtin()]]
+        );
+
+        $this->assertFalse($validator->passes());
+    }
+
+    /** @test */
+    public function it_returns_the_correct_error_message()
+    {
+        $validator = new Validator(
+            $this->translator,
+            ['gtin' => 'invalid-gtin'],
+            ['gtin' => [new MustBeAValidGtin()]]
+        );
+
+        $this->assertEquals(
+            'The gtin must be a valid Global Trade Item Number (GTIN) [8, 12, 13 or 14 digits with a valid check digit]',
+            $validator->errors()->first('gtin')
+        );
+    }
+
+    /** @test */
+    public function the_validation_message_can_be_overridden()
+    {
+        $validator = new Validator(
+            $this->translator,
+            ['gtin' => 'invalid-gtin'],
+            ['gtin' => [new MustBeAValidGtin()]],
+            ['gtin' => 'Custom GTIN validation error message.']
+        );
+
+        $this->assertEquals(
+            'Custom GTIN validation error message.',
+            $validator->errors()->first('gtin')
+        );
+    }
+}

Tests/GtinValidatorTest.php

@@ -0,0 +1,105 @@
+<?php
+
+declare(strict_types=1);
+
+use PHPUnit\Framework\TestCase;
+use Vanilo\Support\Validation\GtinValidator;
+
+class GtinValidatorTest extends TestCase
+{
+    /** @test */
+    public function a_valid_gtin8_should_pass()
+    {
+        $this->assertTrue(GtinValidator::isValid('80000006'));
+    }
+
+    /** @test */
+    public function an_invalid_gtin8_should_not_pass()
+    {
+        $this->assertFalse(GtinValidator::isValid('80000000'));
+    }
+
+    /** @test */
+    public function a_valid_gtin12_should_pass()
+    {
+        $this->assertTrue(GtinValidator::isValid('120000000005'));
+    }
+
+    /** @test */
+    public function an_invalid_gtin12_should_not_pass()
+    {
+        $this->assertFalse(GtinValidator::isValid('120000000000'));
+    }
+
+    /** @test */
+    public function a_valid_gtin13_should_pass()
+    {
+        $this->assertTrue(GtinValidator::isValid('1300000000000'));
+    }
+
+    /** @test */
+    public function an_invalid_gtin13_should_not_pass()
+    {
+        $this->assertFalse(GtinValidator::isValid('1300000000001'));
+    }
+
+    /** @test */
+    public function a_valid_gtin14_should_pass()
+    {
+        $this->assertTrue(GtinValidator::isValid('14000000000003'));
+    }
+
+    /** @test */
+    public function an_invalid_gtin14_should_not_pass()
+    {
+        $this->assertFalse(GtinValidator::isValid('14000000000000'));
+    }
+
+    /** @test */
+    public function a_valid_gtin_integer_value_should_pass()
+    {
+        $this->assertTrue(GtinValidator::isValid(80000006));
+    }
+
+    /** @test */
+    public function a_too_short_value_should_not_pass()
+    {
+        $this->assertFalse(GtinValidator::isValid('7000003'));
+    }
+
+    /** @test */
+    public function a_too_long_value_should_not_pass()
+    {
+        $this->assertFalse(GtinValidator::isValid('150000000000004'));
+    }
+
+    /** @test */
+    public function a_value_with_a_length_of_nine_digits_should_not_pass()
+    {
+        $this->assertFalse(GtinValidator::isValid('900000001'));
+    }
+
+    /** @test */
+    public function a_value_with_a_length_of_ten_digits_should_not_pass()
+    {
+        $this->assertFalse(GtinValidator::isValid('1000000007'));
+    }
+
+    /** @test */
+    public function a_value_with_a_length_of_eleven_digits_should_not_pass()
+    {
+        $this->assertFalse(GtinValidator::isValid('11000000006'));
+    }
+
+    /** @test */
+    public function zeros_should_not_pass()
+    {
+        $this->assertFalse(GtinValidator::isValid('0000000000000'));
+    }
+
+    /** @test */
+    public function a_non_numeric_string_should_not_pass()
+    {
+        $this->assertFalse(GtinValidator::isValid('string'));
+    }
+}

Validation/GtinValidator.php

@@ -0,0 +1,45 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Vanilo\Support\Validation;
+
+class GtinValidator
+{
+    protected static array $cache = [];
+
+    public static function isValid(string|int $gtin): bool
+    {
+        $gtin = (string) $gtin;
+        if (! is_numeric($gtin)) {
+            return false;
+        }
+
+        if (isset(static::$cache[$gtin])) {
+            return static::$cache[$gtin];
+        }
+
+        if (! preg_match('/^\d{8}(?:\d{4,6})?$/', $gtin)) {
+            return false;
+        }
+
+        return static::$cache[$gtin] = static::isCheckSumCorrect($gtin);
+    }
+
+    protected static function isCheckSumCorrect(string $value): bool
+    {
+        return substr($value, 0, -1).collect(str_split($value))
+                ->slice(0, -1)
+                ->pipe(function ($collection) {
+                    return $collection->sum() === 0 ? collect(1) : $collection;
+                })
+                ->reverse()
+                ->values()
+                ->map(function ($digit, $key) {
+                    return $key % 2 === 0 ? $digit * 3 : $digit;
+                })
+                ->pipe(function ($collection) {
+                    return ceil($collection->sum() / 10) * 10 - $collection->sum();
+                }) === $value;
+    }
+}

Validation/Rules/MustBeAValidGtin.php

@@ -0,0 +1,25 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Vanilo\Support\Validation\Rules;
+
+use Closure;
+use Illuminate\Contracts\Validation\ValidationRule;
+use Vanilo\Support\Validation\GtinValidator;
+
+class MustBeAValidGtin implements ValidationRule
+{
+    public function validate(string $attribute, mixed $value, Closure $fail): void
+    {
+        if (!is_string($value) && !is_int($value)) {
+            $fail(__('The :attribute must be a numeric string'));
+
+            return;
+        }
+
+        if (!GtinValidator::isValid($value)) {
+            $fail(__('The :attribute must be a valid Global Trade Item Number (GTIN) [8, 12, 13 or 14 digits with a valid check digit]'));
+        }
+    }
+}