Added empty test

packages/style-engine/class-wp-style-engine-css-rules-container.php

@@ -106,7 +106,7 @@ public function add_rules( $rules ) {
 				if ( ! $rule instanceof WP_Style_Engine_CSS_Rule ) {
 					_doing_it_wrong(
 						__METHOD__,
-						__( 'Rules passed to WP_Style_Engine_CSS_Rules_Containermust be an instance of WP_Style_Engine_CSS_Rule', 'default' ),
+						__( 'Rules passed to WP_Style_Engine_CSS_Rules_Container must be an instance of WP_Style_Engine_CSS_Rule', 'default' ),
 						'6.6.0'
 					);
 					continue;

phpunit/style-engine/class-wp-style-engine-css-rules-container-test.php

@@ -37,22 +37,19 @@ public function test_should_instantiate_with_selector_and_rules() {
 	}
 
 	/**
-	 * Tests that only WP_Style_Engine_CSS_Rule can be added to a container.
+	 * Tests that empty values cannot be added.
 	 *
 	 * @covers ::add_rules
 	 * @covers ::get_rules
 	 */
-	public function test_should_only_add_rule_objects() {
+	public function test_cannot_add_empty_values() {
 		$css_container = new WP_Style_Engine_CSS_Rules_Container_Gutenberg( '@media not all and (hover: hover)' );
 
 		$css_container->add_rules( '' );
-		$this->assertSame( array(), $css_container->get_rules(), 'Return value of get_rules() does not match expected rules when empty string added.' );
+		$this->assertEmpty( $css_container->get_rules(), 'Return value of get_rules() does not match expected rules when empty string added.' );
 
 		$css_container->add_rules( array() );
-		$this->assertSame( array(), $css_container->get_rules(), 'Return value of get_rules() does not match expected rules when array() added.' );
-
-		$css_container->add_rules( new WP_Style_Engine_CSS_Rules_Container_Gutenberg( '@media not all and (hover: hover)' ) );
-		$this->assertSame( array(), $css_container->get_rules(), 'Return value of get_rules() does not match expected rules when unknown class added.' );
+		$this->assertEmpty( $css_container->get_rules(), 'Return value of get_rules() does not match expected rules when array() added.' );
 	}
 
 	/**