Extend integration tests

.github/workflows/integration-tests.yml

@@ -0,0 +1,13 @@
+name: Integration tests
+
+on: [ workflow_dispatch ]
+
+jobs:
+  test:
+    runs-on: ubuntu-22.04
+    steps:
+      - uses: actions/checkout@v3
+      - name: Build and run integration tests
+        run: docker compose run --entrypoint poetry flask run pytest tests/integration/
+      - name: clean-up
+        run: docker compose down -v

docs/development-setup.md

@@ -59,6 +59,15 @@ To run all unit tests, run this command in the project path:
 pytest tests/unit
 ```
 
+To run all integration tests in Docker containers, run the following command in the project path.
+Make sure that you do not have an old volume in use from previous tests, which could lead to conflicts.
+
+```bash
+docker compose run --entrypoint poetry flask run pytest tests/integration/
+# Clean up afterwards:
+docker compose down -v
+```
+
 ## JS and CSS
 
 For the individual html pages the js and css code should be developed in `client-src/**` as 

sketch_map_tool/database/client_celery.py

@@ -18,6 +18,10 @@ def open_connection():
     db_conn.autocommit = True
 
 
+if db_conn is None:
+    open_connection()
+
+
 def close_connection():
     global db_conn
     if isinstance(db_conn, connection) and db_conn.closed == 0:  # 0 if the conn is open