test_that("estimate_ps returns data.frame with PS column", {
  result <- estimate_ps(
    in_df        = small_df,
    exposure_var = "exposure",
    class_vars   = class_vars,
    cont_vars    = cont_vars,
    ps_var       = "ps",
    verbose      = FALSE
  )

  expect_s3_class(result, "data.frame")
  expect_true("ps" %in% names(result))
  expect_equal(nrow(result), nrow(small_df))
  expect_true(all(result$ps >= 0 & result$ps <= 1))
})

test_that("estimate_ps errors when no data provided", {
  expect_error(
    estimate_ps(in_df = NULL, in_csvpath = NULL, verbose = FALSE),
    "Either in_df or in_csvpath"
  )
})

test_that("estimate_ps warns when both in_df and in_csvpath given", {
  expect_warning(
    estimate_ps(
      in_df        = small_df,
      in_csvpath   = sample_csv,
      exposure_var = "exposure",
      class_vars   = class_vars,
      cont_vars    = cont_vars,
      verbose      = FALSE
    ),
    "Both in_df and in_csvpath"
  )
})

test_that("estimate_ps custom ps_var name works", {
  result <- estimate_ps(
    in_df        = small_df,
    exposure_var = "exposure",
    class_vars   = class_vars,
    cont_vars    = cont_vars,
    ps_var       = "my_ps",
    verbose      = FALSE
  )

  expect_true("my_ps" %in% names(result))
})