finally block running before try block ends db call

Question

I am performing input operation on db and trying to return response.

    var response = {}
    try {
        db.put({},(err, data) => {
            if(err) {
                response["message"] = err.message
                response["code"] = 400
            } else {
                response["message"] = "Group created"
                response["code"] = 201
                response["body"] = data.Item   
            }
        })
    } catch (error) {
        response['message'] = "Something went wrong"
        response['code'] = 500
    } finally {
        return response
    }

This code returns null object on success whereas when I tried setting timeout after the db call it returned full response. I think finally block runs without awaiting db call response.

Answer 1

Yes, that would make sense if db.put is asynchronous.

For DynamoDB it looks like you can return a Promise. You could then use await to wait for the response in order to return it.

It would become something like this:

const func = async() => {
  const response = {}
  try {
    try {
      const rv = await db.put({}).promise();
      response["message"] = "Group created"
      response["code"] = 201;
      response["body"] = rv.data.Item;
    } catch (err) {
      response["message"] = err.message;
      response["code"] = 400;
    }
  } catch (error) {
    response['message'] = "Something went wrong";
    response['code'] = 500;
  } finally {
    return response;
  }
}
func().then((val) => console.log(val));