if (

  requiet("betareg")) {
  data("GasolineYield")
  data("FoodExpenditure")

  m1 <- betareg(yield ~ batch + temp, data = GasolineYield)
  m2 <- betareg(I(food / income) ~ income + persons, data = FoodExpenditure)

  test_that("model_info", {
    expect_true(model_info(m1)$is_beta)
    expect_false(model_info(m1)$is_linear)
  })

  test_that("find_predictors", {
    expect_identical(find_predictors(m1), list(conditional = c("batch", "temp")))
    expect_identical(find_predictors(m1, flatten = TRUE), c("batch", "temp"))
    expect_null(find_predictors(m1, effects = "random"))
  })

  test_that("find_response", {
    expect_identical(find_response(m1), "yield")
    expect_identical(find_response(m2), "I(food/income)")
    expect_identical(find_response(m2, combine = FALSE), c("food", "income"))
  })

  test_that("get_response", {
    expect_equal(get_response(m1), GasolineYield$yield)
    expect_equal(get_response(m2), FoodExpenditure[, c("food", "income")])
  })

  test_that("get_varcov", {
    expect_equal(get_varcov(m1, component = "all"), vcov(m1), tolerance = 1e-3)
    expect_equal(get_varcov(m1), vcov(m1)[-12, -12], tolerance = 1e-3)
  })

  test_that("link_inverse", {
    expect_identical(link_inverse(m1)(0.2), plogis(0.2))
  })

  test_that("get_data", {
    expect_equal(nrow(get_data(m1)), 32)
    expect_equal(colnames(get_data(m1)), c("yield", "batch", "temp"))
    expect_equal(nrow(get_data(m2)), 38)
    expect_equal(
      colnames(get_data(m2)),
      c("food", "income", "persons")
    )
  })

  test_that("find_formula", {
    expect_length(find_formula(m1), 1)
    expect_equal(
      find_formula(m1),
      list(conditional = as.formula("yield ~ batch + temp")),
      ignore_attr = TRUE
    )
    expect_equal(
      find_formula(m2),
      list(conditional = as.formula("I(food/income) ~ income + persons")),
      ignore_attr = TRUE
    )
  })

  test_that("find_variables", {
    expect_equal(
      find_variables(m1),
      list(
        response = "yield",
        conditional = c("batch", "temp")
      )
    )
    expect_equal(
      find_variables(m1, flatten = TRUE),
      c("yield", "batch", "temp")
    )
    expect_equal(
      find_variables(m2, flatten = TRUE),
      c("food", "income", "persons")
    )
  })

  test_that("n_obs", {
    expect_equal(n_obs(m1), 32)
  })

  test_that("is_multivariate", {
    expect_false(is_multivariate(m1))
  })

  test_that("linkfun", {
    expect_false(is.null(link_function(m1)))
  })

  test_that("find_parameters", {
    expect_equal(
      find_parameters(m1),
      list(
        conditional = c("(Intercept)", "batch1", "batch2", "batch3", "batch4", "batch5", "batch6", "batch7", "batch8", "batch9", "temp"),
        precision = "(phi)"
      )
    )
    expect_equal(nrow(get_parameters(m1)), 12)
    expect_equal(
      get_parameters(m1)$Parameter,
      c(
        "(Intercept)",
        "batch1",
        "batch2",
        "batch3",
        "batch4",
        "batch5",
        "batch6",
        "batch7",
        "batch8",
        "batch9",
        "temp",
        "(phi)"
      )
    )
  })

  test_that("find_terms", {
    expect_equal(
      find_terms(m2),
      list(
        response = "I(food/income)",
        conditional = c("income", "persons")
      )
    )
  })

  test_that("find_statistic", {
    expect_identical(find_statistic(m1), "z-statistic")
    expect_identical(find_statistic(m2), "z-statistic")
  })

  test_that("get_modelmatrix", {
    mm <- get_modelmatrix(m1)
    expect_true(is.matrix(mm))
    expect_equal(dim(mm), c(32, 11))
    mm <- get_modelmatrix(m1, data = head(GasolineYield))
    expect_true(is.matrix(mm))
    expect_equal(dim(mm), c(6, 11))
  })

  test_that("get_predicted", {
    p <- suppressWarnings(get_predicted(m1))
    expect_s3_class(p, "get_predicted")
    expect_equal(length(p), 32)
    p <- suppressWarnings(get_predicted(m1, data = head(GasolineYield)))
    expect_s3_class(p, "get_predicted")
    expect_equal(length(p), 6)

    # delta method does not work, so we omit SE and issue warning
    expect_warning(get_predicted(m2, predict = "expectation"))
    expect_warning(get_predicted(m2, predict = "link"), NA)
    p1 <- suppressWarnings(get_predicted(m2, predict = "expectation", ci = 0.95))
    p2 <- get_predicted(m2, predict = "link", ci = 0.95)
    p1 <- data.frame(p1)
    p2 <- data.frame(p2)
    expect_true(!"SE" %in% colnames(p1))
    expect_true("SE" %in% colnames(p2))
  })
}
