Source

File: wp-admin/includes/class-wp-automatic-updater.php

public function should_update( $type, $item, $context ) {
		// Used to see if WP_Filesystem is set up to allow unattended updates.
		$skin = new Automatic_Upgrader_Skin;

		if ( $this->is_disabled() ) {
			return false;
		}

		// Only relax the filesystem checks when the update doesn't include new files.
		$allow_relaxed_file_ownership = false;
		if ( 'core' === $type && isset( $item->new_files ) && ! $item->new_files ) {
			$allow_relaxed_file_ownership = true;
		}

		// If we can't do an auto core update, we may still be able to email the user.
		if ( ! $skin->request_filesystem_credentials( false, $context, $allow_relaxed_file_ownership ) || $this->is_vcs_checkout( $context ) ) {
			if ( 'core' === $type ) {
				$this->send_core_update_notification_email( $item );
			}
			return false;
		}

		// Next up, is this an item we can update?
		if ( 'core' === $type ) {
			$update = Core_Upgrader::should_update_to_version( $item->current );
		} elseif ( 'plugin' === $type || 'theme' === $type ) {
			$update = ! empty( $item->autoupdate );

			if ( ! $update && wp_is_auto_update_enabled_for_type( $type ) ) {
				// Check if the site admin has enabled auto-updates by default for the specific item.
				$auto_updates = (array) get_site_option( "auto_update_{$type}s", array() );
				$update       = in_array( $item->{$type}, $auto_updates, true );
			}
		} else {
			$update = ! empty( $item->autoupdate );
		}

		// If the `disable_autoupdate` flag is set, override any user-choice, but allow filters.
		if ( ! empty( $item->disable_autoupdate ) ) {
			$update = $item->disable_autoupdate;
		}

		/**
		 * Filters whether to automatically update core, a plugin, a theme, or a language.
		 *
		 * The dynamic portion of the hook name, `$type`, refers to the type of update
		 * being checked. Potential hook names include:
		 *
		 *  - `auto_update_core`
		 *  - `auto_update_plugin`
		 *  - `auto_update_theme`
		 *  - `auto_update_translation`
		 *
		 * Generally speaking, plugins, themes, and major core versions are not updated
		 * by default, while translations and minor and development versions for core
		 * are updated by default.
		 *
		 * See the {@see 'allow_dev_auto_core_updates'}, {@see 'allow_minor_auto_core_updates'},
		 * and {@see 'allow_major_auto_core_updates'} filters for a more straightforward way to
		 * adjust core updates.
		 *
		 * @since 3.7.0
		 * @since 5.5.0 The `$update` parameter accepts the value of null.
		 *
		 * @param bool|null $update Whether to update. The value of null is internally used
		 *                          to detect whether nothing has hooked into this filter.
		 * @param object    $item   The update offer.
		 */
		$update = apply_filters( "auto_update_{$type}", $update, $item );

		if ( ! $update ) {
			if ( 'core' === $type ) {
				$this->send_core_update_notification_email( $item );
			}
			return false;
		}

		// If it's a core update, are we actually compatible with its requirements?
		if ( 'core' === $type ) {
			global $wpdb;

			$php_compat = version_compare( phpversion(), $item->php_version, '>=' );
			if ( file_exists( WP_CONTENT_DIR . '/db.php' ) && empty( $wpdb->is_mysql ) ) {
				$mysql_compat = true;
			} else {
				$mysql_compat = version_compare( $wpdb->db_version(), $item->mysql_version, '>=' );
			}

			if ( ! $php_compat || ! $mysql_compat ) {
				return false;
			}
		}

		// If updating a plugin or theme, ensure the minimum PHP version requirements are satisfied.
		if ( in_array( $type, array( 'plugin', 'theme' ), true ) ) {
			if ( ! empty( $item->requires_php ) && version_compare( phpversion(), $item->requires_php, '<' ) ) {
				return false;
			}
		}

		return true;
	}