Improve Surge wp-config handling (#1724)

Co-authored-by: Automattic Bot <[email protected]>

Author: pfefferle

.github/changelog/1724-from-description

@@ -0,0 +1,4 @@
+Significance: patch
+Type: fixed
+
+Improved automated setup process for the Surge caching plugin.

integration/class-surge.php

@@ -37,6 +37,10 @@ public static function init() {
 	 * Add the Surge cache config.
 	 */
 	public static function add_cache_config() {
+		if ( \defined( 'WP_CACHE_CONFIG' ) ) {
+			return;
+		}
+
 		$file = self::get_config_file_path();
 
 		if ( ! \wp_is_writable( $file ) ) {
@@ -72,6 +76,10 @@ public static function add_cache_config() {
 	 * Remove the Surge cache config.
 	 */
 	public static function remove_cache_config() {
+		if ( ! \defined( 'WP_CACHE_CONFIG' ) ) {
+			return;
+		}
+
 		$file = self::get_config_file_path();
 
 		if ( ! \wp_is_writable( $file ) ) {

tests/integration/class-test-surge.php

@@ -147,6 +147,8 @@ public function get_active_plugins() {
 	 * @access public
 	 */
 	public function test_init_with_surge_inactive() {
+		// Needs to be set, because of the dummy `wp-config.php` file.
+		\define( 'WP_CACHE_CONFIG', 'dummy' );
 		// phpcs:ignore
 		\file_put_contents( Surge::get_config_file_path(), "<?php\n" . Surge::get_cache_config() . "\n\n/* That's all, stop editing! */" );
 		\add_filter( 'pre_option_active_plugins', array( $this, 'get_inactive_plugins' ) );