data(pop)
data(samp)

lin_formula <- DRYBIO_AG_TPA_live_ADJ ~ tcc16 + elev

set.seed(5)
result <- saeczi(samp,
                 pop, 
                 lin_formula,
                 domain_level = "COUNTYFIPS",
                 mse_est = TRUE,
                 B = 5,
                 parallel = FALSE)

test_that("result[[2]] is a df", {
  expect_s3_class(result[[2]], "data.frame")
})

test_that("mse column is numeric", {
  expect_type(result[[2]][[2]], "double")
})

test_that("est column is numeric", {
  expect_type(result[[2]][[3]], "double")
})

test_that("number of rows in final data frame matches domain levels", {
  expect_equal(nrow(result[[2]]), length(unique(pop$COUNTYFIPS)))
})

test_that("check for error when pop_dat is a vector or list", {
  expect_error(unit_zi(samp_dat = samp$tcc16, pop_dat = pop$DRYBIO_AG_TPA_live_ADJ_TONS, 
                       lin_formula = DRYBIO_AG_TPA_live_ADJ_TONS ~ tcc16, parallel = FALSE))
})