R/connect.R

In EntirelyDS/sqlmapr:

# Connect to MySQL
#' @import mockable

# Make mockable functions from external functions to enable mocking in tests
dbConnect__ %mockable% DBI::dbConnect
dbListConnections__ %mockable% DBI::dbListConnections
dbDisconnect__ %mockable% DBI::dbDisconnect
dbGetInfo__ %mockable% DBI::dbGetInfo
dbIsValid__ %mockable% DBI::dbIsValid
MySQL__ %mockable% RMySQL::MySQL

#' @export
mysql_connect <- function(cred){
  assertive::assert_is_list(cred)
  assertive::assert_all_are_true(
    c('database', 'host', 'port', 'user', 'password') %in% names(cred)
  )
  curr_con <- dbListConnections__(MySQL__())
  if (length(curr_con) > 0){
    matching_con <- which(sapply(curr_con, is_matching_con, cred = cred))
    if (length(matching_con) > 1){
      sapply(
        curr_con[matching_con[2 : length(matching_con)]],
        dbDisconnect__
      )
    }
    con <- curr_con[[matching_con[1]]]

  }else{
    con <- dbConnect__(
      drv = MySQL__(),
      dbname = cred$database,
      host = cred$host,
      port = as.integer(cred$port),
      user = cred$user,
      password = cred$password
    )
  }

  return(con)
}

is_matching_con <- function(con, cred){
  assertive::assert_is_s4(con)
  assertive::assert_all_are_true(dbIsValid__(con))

  con_info <- dbGetInfo__(con)
  check <- con_info$host == cred$host &&
    con_info$dbname == cred$database &&
    con_info$user == cred$user
  return(check)

}