db_state_knex.re

type badStates =
  | ECONNREFUSED /* database not running, or running on different port */
  | SHUTTING_DOWN
  | STARTING_UP
  | ERROR(string);

let db_state = xs => (
  Js.String.includes("ECONNREFUSED", xs),
  Js.String.includes("is shutting down", xs),
  Js.String.includes("is starting up", xs),
);

let stateMatcher: Js.Promise.error => badStates =
  err => {
    let errStr = Js.String.make(err);
    switch (db_state(errStr)) {
    | (true, false, false) => ECONNREFUSED
    | (false, true, false) => SHUTTING_DOWN
    | (false, false, true) => STARTING_UP
    | (_, _, _) => ERROR(errStr)
    };
  };