ONLY, but ignore span with .foobar-detection client.post( url_for("ui.ui_edit.edit_page", uuid="first"), data={"include_filters": 'span,p', "url": test_url, "tags": "", "subtractive_selectors": ".foobar-detection", 'fetch_backend': "html_requests", "time_between_check_use_default": "y"}, follow_redirects=True ) time.sleep(sleep_time_for_fetch_thread) res = client.get( url_for("ui.ui_views.preview_page", uuid="first"), follow_redirects=True ) assert b'foobar-detection' not in res.data assert b'<br' not in res.data assert b'<p' in res.data