MDL-43066 behat: Checking that the site is not already installed

lib/behat/classes/util.php

@@ -69,6 +69,11 @@ class behat_util extends testing_util {
             throw new coding_exception('This method can be only used by Behat CLI tool');
         }
 
+        $tables = $DB->get_tables(false);
+        if (!empty($tables)) {
+            behat_error(BEHAT_EXITCODE_INSTALLED);
+        }
+
         // New dataroot.
         self::reset_dataroot();
 

lib/behat/lib.php

@@ -33,6 +33,7 @@ define('BEHAT_EXITCODE_PERMISSIONS', 252);
 define('BEHAT_EXITCODE_REINSTALL', 253);
 define('BEHAT_EXITCODE_INSTALL', 254);
 define('BEHAT_EXITCODE_COMPOSER', 255);
+define('BEHAT_EXITCODE_INSTALLED', 256);
 
 /**
  * Exits with an error code
@@ -62,6 +63,9 @@ function behat_error($errorcode, $text = '') {
             $path = testing_cli_argument_path('/admin/tool/behat/cli/init.php');
             $text = "Install Behat before enabling it, use:\n php ".$path;
             break;
+        case BEHAT_EXITCODE_INSTALLED:
+            $text = "The Behat site is already installed";
+            break;
         default:
             $text = 'Unknown error ' . $errorcode . ' ' . $text;
             break;