added test for output verification

integration-tests/bats/sql-server.bats

@@ -155,6 +155,11 @@ EOF
     dolt sql -q "show databases;"
     stop_sql_server
 
+     # Assert that log is in JSON format (checking if logs contain `{...}`)
+    if ! grep -q '^{.*}$' log.txt; then
+    exit 1
+    fi
+    
     # assert that logformat in yaml config is not case sensitive
     cat >config.yml <<EOF
 log_format: teXt