WP_HTML_Tag_Processor: Implement get_attribute_names()

lib/experimental/html/class-wp-html-tag-processor.php

@@ -1402,6 +1402,32 @@ public function get_attribute( $name ) {
 		return html_entity_decode( $raw_value );
 	}
 
+	/**
+	 * Returns the names of all attributes in the currently-opened tag.
+	 *
+	 * Example:
+	 * <code>
+	 *     $p = new WP_HTML_Tag_Processor( '<div enabled class="test" data-test-id="14">Test</div>' );
+	 *     $p->next_tag( [ 'class_name' => 'test' ] ) === true;
+	 *     $p->get_attribute_names() === array( 'enabled', 'class', 'data-test-id' );
+	 *
+	 *     $p->next_tag( [] ) === false;
+	 *     $p->get_attribute_names() === null;
+	 * </code>
+	 *
+	 * @since 6.2.0
+	 *
+	 * @param string $prefix Prefix of attributes whose value is requested.
+	 * @return array|null List of attribute names, or `null` if not at a tag.
+	 */
+	function get_attribute_names() {
+		if ( null === $this->tag_name_starts_at ) {
+			return null;
+		}
+
+		return array_keys( $this->attributes );
+	}
+
 	/**
 	 * Returns the lowercase name of the currently-opened tag.
 	 *

phpunit/html/wp-html-tag-processor-test.php

@@ -151,6 +151,18 @@ public function test_attributes_parser_treats_slash_as_attribute_separator() {
 		$this->assertSame( 'test', $p->get_attribute( 'e' ), 'Accessing an existing e="test" did not return "test"' );
 	}
 
+	/**
+	 * @covers WP_HTML_Tag_Processor::get_attribute_names
+	 */
+	public function test_get_attribute_names() {
+		$p = new WP_HTML_Tag_Processor( '<div enabled class="test" data-test-id="14">Test</div>' );
+		$p->next_tag();
+		$this->assertSame(
+			array( 'enabled', 'class', 'data-test-id' ),
+			$p->get_attribute_names()
+		);
+	}
+
 	/**
 	 * @ticket 56299
 	 *