Script Modules: Force-print wp-i18n before translation inline scripts.

Author: manzoorwanijk

src/wp-includes/class-wp-script-modules.php

@@ -387,9 +387,6 @@ public function print_script_module_translations(): void {
 
 		$set_locale_data_js_function = <<<'JS'
 		( domain, translations ) => {
-			if ( ! window.wp?.i18n?.setLocaleData ) {
-				return;
-			}
 			const localeData = translations.locale_data[ domain ] || translations.locale_data.messages;
 			localeData[""].domain = domain;
 			wp.i18n.setLocaleData( localeData, domain );
@@ -414,6 +411,12 @@ public function print_script_module_translations(): void {
 			);
 			$script_id  = "wp-script-module-translation-data-{$id}";
 			$output    .= "\n//# sourceURL=" . rawurlencode( $script_id );
+
+			// Ensure wp-i18n is printed; the inline script below relies on wp.i18n.setLocaleData().
+			if ( ! wp_script_is( 'wp-i18n', 'done' ) ) {
+				wp_scripts()->do_items( array( 'wp-i18n' ) );
+			}
+
 			wp_print_inline_script_tag( $output, array( 'id' => $script_id ) );
 		}
 	}

tests/phpunit/tests/script-modules/wpScriptModules.php

@@ -1986,6 +1986,23 @@ private function get_registered_script_modules( WP_Script_Modules $script_module
 		return $registered_property->getValue( $script_modules );
 	}
 
+	/**
+	 * Returns the inline text of the first SCRIPT tag with the given id, or null if not found.
+	 *
+	 * @param string $markup The HTML markup to search.
+	 * @param string $id     The id attribute to match.
+	 * @return string|null The inline script text, or null if no matching tag was found.
+	 */
+	private function get_inline_script_text( string $markup, string $id ): ?string {
+		$processor = new WP_HTML_Tag_Processor( $markup );
+		while ( $processor->next_tag( 'SCRIPT' ) ) {
+			if ( $id === $processor->get_attribute( 'id' ) ) {
+				return $processor->get_modifiable_text();
+			}
+		}
+		return null;
+	}
+
 	/**
 	 * Data provider.
 	 *
@@ -2741,10 +2758,8 @@ static function ( $relative, $src, $is_module ) use ( &$filtered ) {
 			$this->assertTrue( $filter_args['is_module'], 'Filter should receive $is_module=true for script modules.' );
 		}
 
-		$processor = new WP_HTML_Tag_Processor( $output );
-		$this->assertTrue( $processor->next_tag( 'SCRIPT' ), 'Output should contain a SCRIPT tag.' );
-		$script_text = $processor->get_modifiable_text();
-		$this->assertStringContainsString( 'wp-script-module-translation-data-test-module', $script_text, 'Translation inline script should be printed with the expected ID.' );
+		$script_text = $this->get_inline_script_text( $output, 'wp-script-module-translation-data-test-module' );
+		$this->assertNotNull( $script_text, 'Translation inline script should be printed with the expected ID.' );
 		$this->assertStringContainsString( 'wp.i18n.setLocaleData', $script_text, 'Output should call wp.i18n.setLocaleData().' );
 		$this->assertStringContainsString( 'Hola', $script_text, 'Output should contain the translated string.' );
 	}
@@ -2808,10 +2823,8 @@ static function ( $relative, $src, $is_module ) use ( &$filtered ) {
 			$this->assertTrue( $filter_args['is_module'], 'Filter should receive $is_module=true for script modules.' );
 		}
 
-		$processor = new WP_HTML_Tag_Processor( $output );
-		$this->assertTrue( $processor->next_tag( 'SCRIPT' ), 'Output should contain a SCRIPT tag.' );
-		$script_text = $processor->get_modifiable_text();
-		$this->assertStringContainsString( 'wp-script-module-translation-data-dep-module', $script_text, 'Dependency module translations should be printed.' );
+		$script_text = $this->get_inline_script_text( $output, 'wp-script-module-translation-data-dep-module' );
+		$this->assertNotNull( $script_text, 'Dependency module translations should be printed.' );
 		$this->assertStringContainsString( 'Mundo', $script_text, 'Output should contain the dependency translation.' );
 	}