Source

File: wp-admin/includes/class-wp-site-health.php

function detect_plugin_theme_auto_update_issues() {
		$mock_plugin = (object) array(
			'id'            => 'w.org/plugins/a-fake-plugin',
			'slug'          => 'a-fake-plugin',
			'plugin'        => 'a-fake-plugin/a-fake-plugin.php',
			'new_version'   => '9.9',
			'url'           => 'https://wordpress.org/plugins/a-fake-plugin/',
			'package'       => 'https://downloads.wordpress.org/plugin/a-fake-plugin.9.9.zip',
			'icons'         => array(
				'2x' => 'https://ps.w.org/a-fake-plugin/assets/icon-256x256.png',
				'1x' => 'https://ps.w.org/a-fake-plugin/assets/icon-128x128.png',
			),
			'banners'       => array(
				'2x' => 'https://ps.w.org/a-fake-plugin/assets/banner-1544x500.png',
				'1x' => 'https://ps.w.org/a-fake-plugin/assets/banner-772x250.png',
			),
			'banners_rtl'   => array(),
			'tested'        => '5.5.0',
			'requires_php'  => '5.6.20',
			'compatibility' => new stdClass(),
		);

		$mock_theme = (object) array(
			'theme'        => 'a-fake-theme',
			'new_version'  => '9.9',
			'url'          => 'https://wordpress.org/themes/a-fake-theme/',
			'package'      => 'https://downloads.wordpress.org/theme/a-fake-theme.9.9.zip',
			'requires'     => '5.0.0',
			'requires_php' => '5.6.20',
		);

		$type = 'plugin';
		/** This filter is documented in wp-admin/includes/class-wp-automatic-updater.php */
		$test_plugins_enabled = apply_filters( "auto_update_{$type}", true, $mock_plugin );

		$type = 'theme';
		/** This filter is documented in wp-admin/includes/class-wp-automatic-updater.php */
		$test_themes_enabled = apply_filters( "auto_update_{$type}", true, $mock_theme );

		$ui_enabled_for_plugins = wp_is_auto_update_enabled_for_type( 'plugin' );
		$ui_enabled_for_themes  = wp_is_auto_update_enabled_for_type( 'theme' );
		$plugin_filter_present  = has_filter( 'auto_update_plugin' );
		$theme_filter_present   = has_filter( 'auto_update_theme' );

		if ( ( ! $test_plugins_enabled && $ui_enabled_for_plugins )
			|| ( ! $test_themes_enabled && $ui_enabled_for_themes )
		) {
			return (object) array(
				'status'  => 'critical',
				'message' => __( 'Auto-updates for plugins and/or themes appear to be disabled, but settings are still set to be displayed. This could cause auto-updates to not work as expected.' ),
			);
		}

		if ( ( ! $test_plugins_enabled && $plugin_filter_present )
			&& ( ! $test_themes_enabled && $theme_filter_present )
		) {
			return (object) array(
				'status'  => 'recommended',
				'message' => __( 'Auto-updates for plugins and themes appear to be disabled. This will prevent your site from receiving new versions automatically when available.' ),
			);
		} elseif ( ! $test_plugins_enabled && $plugin_filter_present ) {
			return (object) array(
				'status'  => 'recommended',
				'message' => __( 'Auto-updates for plugins appear to be disabled. This will prevent your site from receiving new versions automatically when available.' ),
			);
		} elseif ( ! $test_themes_enabled && $theme_filter_present ) {
			return (object) array(
				'status'  => 'recommended',
				'message' => __( 'Auto-updates for themes appear to be disabled. This will prevent your site from receiving new versions automatically when available.' ),
			);
		}

		return (object) array(
			'status'  => 'good',
			'message' => __( 'There appear to be no issues with plugin and theme auto-updates.' ),
		);
	}