),
					'6.3.0'
				);
				return false;
			}
		} elseif ( 'fetchpriority' === $key ) {
			if ( empty( $value ) ) {
				$value = 'auto';
			}
			if ( ! $this->is_valid_fetchpriority( $value ) ) {
				_doing_it_wrong(
					__METHOD__,
					sprintf(
						/* translators: 1: $fetchpriority, 2: $handle */
						__( 'Invalid fetchpriority `%1$s` defined for `%2$s` during script registration.' ),
						is_string( $value ) ? $value : gettype( $value ),
						$handle
					),
					'6.9.0'
				);
				return false;
			} elseif ( ! $this->registered[ $handle ]->src ) {
				_doing_it_wrong(
					__METHOD__,
					sprintf(
						/* translators: 1: $fetchpriority, 2: $handle */
						__( 'Cannot supply a fetchpriority `%1$s` for script `%2$s` because it is an alias (it lacks a `src` value).' ),
						is_string( $value ) ? $value : gettype( $value ),
						$handle
					),
					'6.9.0'
				);
				return false;
			}
		}
		return parent::add_data( $handle, $key, $value );
	}

	/**
	 * Gets all dependents of a script.
	 *
	 * This is not recursive.
	 *
	 * @since 6.3.0
	 *
	 * @param string $handle The script handle.
	 * @return string[] Script handles.
	 */
	private function get_dependents( $handle ) {
		// Check if dependents map for the handle in question is present. If so, use it.
		if ( isset( $this->dependents_map[ $handle ] ) ) {
			return $this->dependents_map[ $handle ];
		}

		$dependents = array();

		// Iterate over all registered scripts, finding dependents of the script passed to this method.
		foreach ( $this->registered as $registered_handle => $args ) {
			if ( in_array( $handle, $args->deps, true ) ) {
				$dependents[] = $registered_handle;
			}
		}

		// Add the handles dependents to the map to ease future lookups.
		$this->dependents_map[ $handle ] = $dependents;

		return $dependents;
	}

	/**
	 * Checks if the strategy passed is a valid delayed (non-blocking) strategy.
	 *
	 * @since 6.3.0
	 *
	 * @param string|mixed $strategy The strategy to check.
	 * @return bool True if $strategy is one of the delayed strategies, otherwise false.
	 */
	private function is_delayed_strategy( $strategy ): bool {
		return in_array(
			$strategy,
			$this->delayed_strategies,
			true
		);
	}

	/**
	 * Checks if the provided fetchpriority is valid.
	 *
	 * @since 6.9.0
	 *
	 * @param string|mixed $priority Fetch priority.
	 * @return bool Whether valid fetchpriority.
	 */
	private function is_valid_fetchpriority( $priority ): bool {
		return in_array( $priority, array( 'auto', 'low', 'high' ), true );
	}

	/**
	 * Gets the best eligible loading strategy for a script.
	 *
	 * @since 6.3.0
	 *
	 * @param string $handle The script handle.
	 * @return string The best eligible loading strategy.
	 */
	private function get_eligible_loading_strategy( $handle ) {
		$intended_strategy = (string) $this->get_data( $handle, 'strategy' );

		// Bail early if there is no intended strategy.
		if ( ! $intended_strategy ) {
			return '';
		}

		/*
		 * If the intended strategy is 'defer', limit the initial list of eligible
		 * strategies, since 'async' can fallback to 'defer', but not vice-versa.
		 */
		$initial_strategy = ( 'defer' === $intended_strategy ) ? array( 'defer' ) : null;

		$eligible_strategies = $this->filter_eligible_strategies( $handle, $initial_strategy );

		// Return early once we know the eligible strategy is blocking.
		if ( empty( $eligible_strategies ) ) {
			return '';
		}

		return in_array( 'async', $eligible_strategies, true ) ? 'async' : 'defer';
	}

	/**
	 * Filter the list of eligible loading strategies for a script.
	 *
	 * @since 6.3.0
	 *
	 * @param string                  $handle              The script handle.
	 * @param string[]|null           $eligible_strategies Optional. The list of strategies to filter. Default null.
	 * @param array<string, true>     $checked             Optional. An array of already checked script handles, used to avoid recursive loops.
	 * @param array<string, string[]> $stored_results      Optional. An array of already computed eligible loading strategies by handle, used to increase performance in large dependency lists.
	 * @return string[] A list of eligible loading strategies that could be used.
	 */
	private function filter_eligible_strategies( $handle, $eligible_strategies = null, $checked = array(), array &$stored_results = array() ) {
		if ( isset( $stored_results[ $handle ] ) ) {
			return $stored_results[ $handle ];
		}

		// If no strategies are being passed, all strategies are eligible.
		if ( null === $eligible_strategies ) {
			$eligible_strategies = $this->delayed_strategies;
		}

		// If this handle was already checked, return early.
		if ( isset( $checked[ $handle ] ) ) {
			return $eligible_strategies;
		}

		// Mark this handle as checked.
		$checked[ $handle ] = true;

		// If this handle isn't registered, don't filter anything and return.
		if ( ! isset( $this->registered[ $handle ] ) ) {
			return $eligible_strategies;
		}

		// If the handle is not enqueued, don't filter anything and return.
		if ( ! $this->query( $handle, 'enqueued' ) ) {
			return $eligible_strategies;
		}

		$is_alias          = (bool) ! $this->registered[ $handle ]->src;
		$intended_strategy = $this->get_data( $handle, 'strategy' );

		// For non-alias handles, an empty intended strategy filters all strategies.
		if ( ! $is_alias && empty( $intended_strategy ) ) {
			return array();
		}

		// Handles with inline scripts attached in the 'after' position cannot be delayed.
		if ( $this->has_inline_script( $handle, 'after' ) ) {
			return array();
		}

		// If the intended strategy is 'defer', filter out 'async'.
		if ( 'defer' === $intended_strategy ) {
			$eligible_strategies = array( 'defer' );
		}

		$dependents = $this->get_dependents( $handle );

		// Recursively filter eligible strategies for dependents.
		foreach ( $dependents as $dependent ) {
			// Bail early once we know the eligible strategy is blocking.
			if ( empty( $eligible_strategies ) ) {
				return array();
			}

			$eligible_strategies = $this->filter_eligible_strategies( $dependent, $eligible_strategies, $checked, $stored_results );
		}
		$stored_results[ $handle ] = $eligible_strategies;
		return $eligible_strategies;
	}

	/**
	 * Gets the highest fetch priority for a given script and all of its dependent scripts.
	 *
	 * @since 6.9.0
	 * @see self::filter_eligible_strategies()
	 * @see WP_Script_Modules::get_highest_fetchpriority()
	 *
	 * @param string                $handle         Script module ID.
	 * @param array<string, true>   $checked        Optional. An array of already checked script handles, used to avoid recursive loops.
	 * @param array<string, string> $stored_results Optional. An array of already computed max priority by handle, used to increase performance in large dependency lists.
	 * @return string|null Highest fetch priority for the script and its dependents.
	 */
	private function get_highest_fetchpriority_with_dependents( string $handle, array $checked = array(), array &$stored_results = array() ): ?string {
		if ( isset( $stored_results[ $handle ] ) ) {
			return $stored_results[ $handle ];
		}

		// If there is a recursive dependency, return early.
		if ( isset( $checked[ $handle ] ) ) {
			return null;
		}

		// Mark this handle as checked to guard against infinite recursion.
		$checked[ $handle ] = true;

		// Abort if the script is not enqueued or a dependency of an enqueued script.
		if ( ! $this->query( $handle, 'enqueued' ) ) {
			return null;
		}

		$fetchpriority = $this->get_data( $handle, 'fetchpriority' );
		if ( ! $this->is_valid_fetchpriority( $fetchpriority ) ) {
			$fetchpriority = 'auto';
		}

		static $priorities   = array(
			'low',
			'auto',
			'high',
		);
		$high_priority_index = count( $priorities ) - 1;

		$highest_priority_index = (int) array_search( $fetchpriority, $priorities, true );
		if ( $highest_priority_index !== $high_priority_index ) {
			foreach ( $this->get_dependents( $handle ) as $dependent_handle ) {
				$dependent_priority = $this->get_highest_fetchpriority_with_dependents( $dependent_handle, $checked, $stored_results );
				if ( is_string( $dependent_priority ) ) {
					$highest_priority_index = max(
						$highest_priority_index,
						(int) array_search( $dependent_priority, $priorities, true )
					);
					if ( $highest_priority_index === $high_priority_index ) {
						break;
					}
				}
			}
		}
		$stored_results[ $handle ] = $priorities[ $highest_priority_index ]; // @phpstan-ignore parameterByRef.type (We know the index is valid and that this will be a string.)
		return $priorities[ $highest_priority_index ];
	}

	/**
	 * Gets data for inline scripts registered for a specific handle.
	 *
	 * @since 6.3.0
	 *
	 * @param string $handle   Name of the script to get data for. Must be lowercase.
	 * @param string $position The position of the inline script.
	 * @return bool Whether the handle has an inline script (either before or after).
	 */
	private function has_inline_script( $handle, $position = null ) {
		if ( $position && in_array( $position, array( 'before', 'after' ), true ) ) {
			return (bool) $this->get_data( $handle, $position );
		}

		return (bool) ( $this->get_data( $handle, 'before' ) || $this->get_data( $handle, 'after' ) );
	}

	/**
	 * Resets class properties.
	 *
	 * @since 2.8.0
	 */
	public function reset() {
		$this->do_concat      = false;
		$this->print_code     = '';
		$this->concat         = '';
		$this->concat_version = '';
		$this->print_html     = '';
		$this->ext_version    = '';
		$this->ext_handles    = '';
	}

	/**
	 * Gets a script-specific dependency warning message.
	 *
	 * @since 6.9.1
	 *
	 * @param string   $handle                     Script handle with missing dependencies.
	 * @param string[] $missing_dependency_handles Missing dependency handles.
	 * @return string Formatted, localized warning message.
	 */
	protected function get_dependency_warning_message( $handle, $missing_dependency_handles ) {
		return sprintf(
			/* translators: 1: Script handle, 2: List of missing dependency handles. */
			__( 'The script with the handle "%1$s" was enqueued with dependencies that are not registered: %2$s.' ),
			$handle,
			implode( wp_get_list_item_separator(), $missing_dependency_handles )
		);
	}
}