Validate and prepare GTIN in structured data (#50926)

* Validate and prepare GTIN in structured data

* Add changelog

* PHPCS

* PHPCS

* Verify gtin is string in prepare gtin

* Tweak tests

* PHPCS

* Tweak is_valid_gtin

* LINT

* Update plugins/woocommerce/includes/class-wc-structured-data.php

Co-authored-by: Mik <mikkamp@users.noreply.github.com>

* Update plugins/woocommerce/includes/class-wc-structured-data.php

Co-authored-by: Mik <mikkamp@users.noreply.github.com>

* Update plugins/woocommerce/includes/class-wc-structured-data.php

Co-authored-by: Mik <mikkamp@users.noreply.github.com>

---------

Co-authored-by: Mik <mikkamp@users.noreply.github.com>

plugins/woocommerce/changelog/tweak-gtin-structured-data

@@ -0,0 +1,4 @@
+Significance: patch
+Type: tweak
+
+Validate and prepare GTIN in structured data

plugins/woocommerce/includes/class-wc-structured-data.php

@@ -214,9 +214,9 @@ class WC_Structured_Data {
 			$markup['sku'] = $product->get_id();
 		}
 
-		// Add GTIN only if it's a valid number.
+		// Prepare GTIN and load it if it's valid.
-		$gtin = $product->get_global_unique_id();
+		$gtin = $this->prepare_gtin( $product->get_global_unique_id() );
-		if ( $gtin && is_numeric( $gtin ) ) {
+		if ( $this->is_valid_gtin( $gtin ) ) {
 			$markup['gtin'] = $gtin;
 		}
 
@@ -577,4 +577,30 @@ class WC_Structured_Data {
 
 		$this->set_data( apply_filters( 'woocommerce_structured_data_order', $markup, $sent_to_admin, $order ), true );
 	}
+
+	/**
+	 * Check if a GTIN is valid.
+	 * A valid GTIN is a string containing 8,12,13 or 14 digits.
+	 *
+	 * @see https://schema.org/gtin
+	 * @param string $gtin The GTIN to check.
+	 * @return bool True if valid. False otherwise.
+	 */
+	public function is_valid_gtin( $gtin ) {
+		return is_string( $gtin ) && preg_match( '/^(\d{8}|\d{12,14})$/', $gtin );
+	}
+
+	/**
+	 * Prepare a GTIN input removing everything except numbers.
+	 *
+	 * @param string $gtin The GTIN to prepare.
+	 * @return string Empty string if no GTIN is provided or the string with the replacements.
+	 */
+	public function prepare_gtin( $gtin ) {
+		if ( ! $gtin || ! is_string( $gtin ) ) {
+			return '';
+		}
+
+		return preg_replace( '/[^0-9]/', '', $gtin );
+	}
 }

plugins/woocommerce/tests/php/includes/class-wc-structured-data-test.php

@@ -0,0 +1,83 @@
+<?php
+declare( strict_types = 1 );
+
+/**
+ * Class WC_Structured_Data_Test.
+ */
+class WC_Structured_Data_Test extends \WC_Unit_Test_Case {
+
+	/** @var WC_Structured_Data $structured_data */
+	public $structured_data;
+
+	/**
+	 * Set up test
+	 *
+	 * @return void
+	 */
+	public function setUp(): void {
+		include_once WC_ABSPATH . 'includes/class-wc-structured-data.php';
+		$this->structured_data = new WC_Structured_Data();
+		parent::setUp();
+	}
+
+	/**
+	 * Test is_valid_gtin function
+	 *
+	 * @return void
+	 */
+	public function test_is_valid_gtin(): void {
+
+		$valid_gtins = array(
+			'12345678',
+			'123456789012',
+			'1234567890123',
+			'12345678901234',
+		);
+
+		$invalid_gtins = array(
+			'',
+			null,
+			false,
+			12345678,
+			123.4e-5,
+			+1234567,
+			'abcdefgh',
+			'-9999999',
+			'12-45-66',
+			'123',
+			'123456789012345',
+			'123456789',
+			'1234567890',
+			'12 34 56 78',
+			'12 34 56',
+			'+12345678',
+			'123.4e-5',
+		);
+
+		foreach ( $valid_gtins as $valid_gtin ) {
+			$this->assertTrue( $this->structured_data->is_valid_gtin( $valid_gtin ) );
+		}
+
+		foreach ( $invalid_gtins as $invalid_gtin ) {
+			$this->assertFalse( $this->structured_data->is_valid_gtin( $invalid_gtin ) );
+		}
+	}
+
+	/**
+	 * Test prepare_gtin function
+	 *
+	 * @return void
+	 */
+	public function test_prepare_gtin(): void {
+		$this->assertEquals( $this->structured_data->prepare_gtin( '123-456-78' ), '12345678' );
+		$this->assertEquals( $this->structured_data->prepare_gtin( '-123-456-78' ), '12345678' );
+		$this->assertEquals( $this->structured_data->prepare_gtin( 'GTIN: 123-456-78' ), '12345678' );
+		$this->assertEquals( $this->structured_data->prepare_gtin( '123 456 78' ), '12345678' );
+		$this->assertEquals( $this->structured_data->prepare_gtin( null ), '' );
+		$this->assertEquals( $this->structured_data->prepare_gtin( 'GTIN' ), '' );
+		$this->assertEquals( $this->structured_data->prepare_gtin( 123 ), '' );
+		$this->assertEquals( $this->structured_data->prepare_gtin( array( '123-456-78', '123-456-78' ) ), '' );
+		$this->assertEquals( $this->structured_data->prepare_gtin( '+12345678' ), '12345678' );
+		$this->assertEquals( $this->structured_data->prepare_gtin( '123.4e-5' ), '12345' );
+	}
+}