MDL-80689 behat: add a transformation to get dirroot

Also, back-port #wwwroot# from MDL-78619 which was not backported at the time.

lib/tests/behat/behat_transformations.php

@@ -133,6 +133,30 @@ class behat_transformations extends behat_base {
         return $tablenode;
     }
 
+    /**
+     * Convert #wwwroot# to the wwwroot config value, so it is
+     * possible to reference fully qualified URLs within the site.
+     *
+     * @Transform /^((.*)#wwwroot#(.*))$/
+     * @param string $string
+     * @return string
+     */
+    public function arg_insert_wwwroot(string $string): string {
+        return $this->replace_wwwroot($string);
+    }
+
+    /**
+     * Convert #dirroot# to the dirroot config value, so it is
+     * possible to reference files (e.g. fixtures) with an absolute path.
+     *
+     * @Transform /^((.*)#dirroot#(.*))$/
+     * @param string $string
+     * @return string
+     */
+    public function arg_insert_dirroot(string $string): string {
+        return $this->replace_dirroot($string);
+    }
+
     /**
      * Replaces $NASTYSTRING vars for a nasty string.
      *
@@ -176,4 +200,26 @@ class behat_transformations extends behat_base {
             return $time;
         }
     }
+
+    /**
+     * Replace #wwwroot# with the actual wwwroot config value.
+     *
+     * @param string $string String to attempt the replacement in.
+     * @return string
+     */
+    protected function replace_wwwroot(string $string): string {
+        global $CFG;
+        return str_replace('#wwwroot#', $CFG->wwwroot, $string);
+    }
+
+    /**
+     * Replace #dirroot# with the actual dirroot config value.
+     *
+     * @param string $string String to attempt the replacement in.
+     * @return string
+     */
+    protected function replace_dirroot(string $string): string {
+        global $CFG;
+        return str_replace('#dirroot#', $CFG->dirroot, $string);
+    }
 }