From 70c7962fee55cd10ffb2ab35c19c7d78359bef07 Mon Sep 17 00:00:00 2001
From: Pascal Birchler <swissspidy@git.wordpress.org>
Date: Tue, 17 Sep 2024 20:56:03 +0000
Subject: [PATCH] I18N: Add a new way to determine whether a translation is
 available.

A new `has_translation()` function can be used to determine whether a translation exists for a given string.

Props louiswol94, swissspidy, drzraf, ckanitz, tomhine, mchirag2002, samuelsilvapt.
Fixes #52696.



git-svn-id: https://develop.svn.wordpress.org/trunk@59029 602fd350-edb4-49c9-b593-d223f7449a82
---
 src/wp-includes/l10n.php                      | 14 ++++++
 .../l10n/class-wp-translation-controller.php  | 18 +++++++
 .../tests/l10n/wpTranslationController.php    | 47 +++++++++++++++++++
 3 files changed, 79 insertions(+)

diff --git a/src/wp-includes/l10n.php b/src/wp-includes/l10n.php
index 038b9160499ce..1f3532a40ded5 100644
--- a/src/wp-includes/l10n.php
+++ b/src/wp-includes/l10n.php
@@ -1988,3 +1988,17 @@ function wp_get_word_count_type() {
 
 	return $wp_locale->get_word_count_type();
 }
+
+/**
+ * Returns a boolean to indicate whether a translation exists for a given string with optional text domain and locale.
+ *
+ * @since 6.7.0
+ *
+ * @param string  $singular   Singular translation to check.
+ * @param string  $textdomain Optional. Text domain. Default 'default'.
+ * @param ?string $locale     Optional. Locale. Default current locale.
+ * @return bool  True if the translation exists, false otherwise.
+ */
+function has_translation( string $singular, string $textdomain = 'default', ?string $locale = null ): bool {
+	return WP_Translation_Controller::get_instance()->has_translation( $singular, $textdomain, $locale );
+}
diff --git a/src/wp-includes/l10n/class-wp-translation-controller.php b/src/wp-includes/l10n/class-wp-translation-controller.php
index 295e3fcac79a2..c68cf32add6d6 100644
--- a/src/wp-includes/l10n/class-wp-translation-controller.php
+++ b/src/wp-includes/l10n/class-wp-translation-controller.php
@@ -434,4 +434,22 @@ protected function get_files( string $textdomain = 'default', ?string $locale =
 
 		return $this->loaded_translations[ $locale ][ $textdomain ] ?? array();
 	}
+
+	/**
+	 * Returns a boolean to indicate whether a translation exists for a given string with optional text domain and locale.
+	 *
+	 * @since 6.7.0
+	 *
+	 * @param string  $singular   Singular translation to check.
+	 * @param string  $textdomain Optional. Text domain. Default 'default'.
+	 * @param ?string $locale     Optional. Locale. Default current locale.
+	 * @return bool  True if the translation exists, false otherwise.
+	 */
+	public function has_translation( string $singular, string $textdomain = 'default', ?string $locale = null ): bool {
+		if ( null === $locale ) {
+			$locale = $this->current_locale;
+		}
+
+		return false !== $this->locate_translation( $singular, $textdomain, $locale );
+	}
 }
diff --git a/tests/phpunit/tests/l10n/wpTranslationController.php b/tests/phpunit/tests/l10n/wpTranslationController.php
index 6c8fb6dc9d300..00afeaa095cea 100644
--- a/tests/phpunit/tests/l10n/wpTranslationController.php
+++ b/tests/phpunit/tests/l10n/wpTranslationController.php
@@ -361,4 +361,51 @@ public function test_switch_to_locale_translations_stay_loaded_custom_textdomain
 		$this->assertSame( 'Este es un plugin dummy', $actual );
 		$this->assertSame( 'This is a dummy plugin', $after );
 	}
+
+	/**
+	 * @ticket 52696
+	 * @covers ::has_translation
+	 */
+	public function test_has_translation_with_existing_translation() {
+		load_textdomain( 'wp-tests-domain', DIR_TESTDATA . '/pomo/simple.mo' );
+		$this->assertTrue( WP_Translation_Controller::get_instance()->has_translation( 'baba', 'wp-tests-domain', 'en_US' ) );
+	}
+
+	/**
+	 * @ticket 52696
+	 * @covers ::has_translation
+	 */
+	public function test_has_translation_with_no_translation() {
+		$this->assertFalse( WP_Translation_Controller::get_instance()->has_translation( 'Goodbye', 'wp-tests-domain', 'en_US' ) );
+	}
+
+	/**
+	 * @ticket 52696
+	 * @covers ::has_translation
+	 */
+	public function test_has_translation_with_different_textdomain() {
+		load_textdomain( 'wp-tests-domain', DIR_TESTDATA . '/pomo/simple.mo' );
+		$this->assertFalse( WP_Translation_Controller::get_instance()->has_translation( 'baba', 'custom-domain', 'en_US' ) );
+	}
+
+	/**
+	 * @ticket 52696
+	 * @covers ::has_translation
+	 */
+	public function test_has_translation_with_different_locale() {
+		switch_to_locale( 'es_ES' );
+		load_textdomain( 'wp-tests-domain', DIR_TESTDATA . '/pomo/simple.mo' );
+		$actual = WP_Translation_Controller::get_instance()->has_translation( 'baba', 'wp-tests-domain', 'es_ES' );
+		restore_previous_locale();
+		$this->assertTrue( $actual );
+	}
+
+	/**
+	 * @ticket 52696
+	 * @covers ::has_translation
+	 */
+	public function test_has_translation_with_no_locale_provided() {
+		load_textdomain( 'wp-tests-domain', DIR_TESTDATA . '/pomo/simple.mo' );
+		$this->assertTrue( WP_Translation_Controller::get_instance()->has_translation( 'baba', 'wp-tests-domain' ) );
+	}
 }