replace behave BDD API tests with pytest-bdd tests

test/bdd/utils/db.py

@@ -0,0 +1,44 @@
+# SPDX-License-Identifier: GPL-3.0-or-later
+#
+# This file is part of Nominatim. (https://nominatim.org)
+#
+# Copyright (C) 2025 by the Nominatim developer community.
+# For a full list of authors see the git log.
+"""
+Helper functions for managing test databases.
+"""
+import psycopg
+from psycopg import sql as pysql
+
+
+class DBManager:
+
+    def __init__(self, purge=False):
+        self.purge = purge
+
+    def check_for_db(self, dbname):
+        """ Check if the given DB already exists.
+            When the purge option is set, then an existing database will
+            be deleted and the function returns that it does not exist.
+        """
+        if self.purge:
+            self.drop_db(dbname)
+            return False
+
+        return self.exists_db(dbname)
+
+    def drop_db(self, dbname):
+        """ Drop the given database if it exists.
+        """
+        with psycopg.connect(dbname='postgres') as conn:
+            conn.autocommit = True
+            conn.execute(pysql.SQL('DROP DATABASE IF EXISTS')
+                         + pysql.Identifier(dbname))
+
+    def exists_db(self, dbname):
+        """ Check if a database with the given name exists already.
+        """
+        with psycopg.connect(dbname='postgres') as conn:
+            cur = conn.execute('select count(*) from pg_database where datname = %s',
+                               (dbname,))
+            return cur.fetchone()[0] == 1