MDL-78619 behat: Add wwwroot transformation

This will replace #wwwroot# with the value of the wwwroot config.
This is useful where a FQDN within the test instance is required.

lib/tests/behat/behat_transformations.php

@@ -107,6 +107,7 @@ public function arg_time_to_string($time) {
      * @return TableNode The transformed table
      */
     public function tablenode_transformations(TableNode $tablenode) {
+        global $CFG;
         // Walk through all values including the optional headers.
         $rows = $tablenode->getRows();
         foreach ($rows as $rowkey => $row) {
@@ -123,6 +124,11 @@ public function tablenode_transformations(TableNode $tablenode) {
                         $rows[$rowkey][$colkey] = $this->get_transformed_timestamp($match[1]);
                     }
                 }
+
+                // Transform wwwroot.
+                if (preg_match('/#wwwroot#/', $rows[$rowkey][$colkey])) {
+                    $rows[$rowkey][$colkey] = $this->replace_wwwroot($rows[$rowkey][$colkey]);
+                }
             }
         }
 
@@ -133,6 +139,18 @@ public function tablenode_transformations(TableNode $tablenode) {
         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);
+    }
+
     /**
      * Replaces $NASTYSTRING vars for a nasty string.
      *
@@ -176,4 +194,15 @@ protected function get_transformed_timestamp($time) {
             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);
+    }
 }