set jest to connect to test database

hi guys working on an existing project which has jest setup on it but its not specifying to run in the test database, just ran tests and it messed up my dev db. What do I need to do specify that it should run the test database called "test"? All I have is the package.json which says:

  "jest": {
    "collectCoverage": false,
    "testEnvironment": "node",
    "verbose": true,
    "bail": true,
    "roots": [
      "./tests"
    ]
  },

No tests setup file exists, I'd rather use a setup file than the package.json