test_that("convertIds", {
  reg = makeTestRegistry()
  batchMap(identity, 1:10, reg = reg)
  reg$status = reg$status[-3, ]

  tab = convertIds(reg, NULL)
  expect_equal(tab, NULL)

  tab = convertIds(reg, 1:10)
  expect_data_table(tab, ncol = 1, nrow = 9, key = "job.id")
  expect_copied(tab, reg$status)

  tab = convertIds(reg, findJobs(reg = reg))
  expect_data_table(tab, ncol = 1, nrow = 9, key = "job.id")
  expect_copied(tab, reg$status)

  tab = convertIds(reg, data.table(job.id = 3:4, key = "job.id"))
  expect_data_table(tab, ncol = 1, nrow = 1, key = "job.id")

  tab = convertIds(reg, as.data.frame(findJobs(reg = reg)))
  expect_data_table(tab, ncol = 1, key = "job.id")
  expect_copied(tab, reg$status)

  tab = convertIds(reg, 10:8)
  expect_data_table(tab, ncol = 1, nrow = 3, key = "job.id")
  expect_equal(tab$job.id, 8:10)
  expect_copied(tab, reg$status)

  tab = convertIds(reg, 10:8, keep.order = TRUE)
  expect_data_table(tab, ncol = 1, nrow = 3)
  expect_equal(tab$job.id, 10:8)

  ids = findJobs(reg = reg)
  ids$chunk = 9:1
  tab = convertIds(reg, ids, keep.order = TRUE, keep.extra = "chunk")
  expect_data_table(tab, ncol = 2, nrow = 9, key = "job.id") # keep index if possible

  setorderv(ids, "chunk")
  tab = convertIds(reg, ids, keep.order = TRUE, keep.extra = "chunk")
  expect_data_table(tab, ncol = 2, nrow = 9)
  expect_null(key(tab))
  expect_equal(tab$job.id, setdiff(10:1, 3L))

  expect_error(convertIds(reg, c(2, 2)), "Duplicated ids")
  expect_error(convertIds(reg, as.character(1:3)), "not recognized")

  # issue #40
  ids = ids[list(5:10), on = "job.id"][, "chunk" := chunk(job.id, chunk.size = 3)]
  ids = convertIds(reg, ids,  keep.extra = c("job.id", "chunk"))
  expect_data_table(ids, any.missing = FALSE)
})