## Test handling `by` variables in smooths/GAMs

test_that("draw() works with continuous by", {
  plt <- draw(su_m_cont_by)

  skip_on_ci()
  expect_doppelganger("continuous by-variable smmoth", plt)
})

test_that("draw() works with continuous by and fixed scales", {
  plt <- draw(su_m_cont_by, scales = "fixed")
  expect_s3_class(plt, "ggplot")

  expect_doppelganger("continuous by-variable smmoth fixed scales", plt)
})

test_that("is_by_smooth() is TRUE with continuous by", {
  expect_true(is_by_smooth(su_m_cont_by[["smooth"]][[1]]))
})

test_that("is_factor_by_smooth() is FALSE with continuous by", {
  expect_false(is_factor_by_smooth(su_m_cont_by[["smooth"]][[1]]))
})

test_that("is_continuous_by_smooth() is TRUE with continuous by", {
  expect_true(is_continuous_by_smooth(su_m_cont_by[["smooth"]][[1]]))
})

test_that("get_by_smooth works", {
  sm <- get_by_smooth(su_m_factor_by, "s(x2)", level = "1")
  expect_s3_class(sm, "mgcv.smooth")
  expect_equal(sm, su_m_factor_by[["smooth"]][[1L]])

  sm <- get_by_smooth(su_m_factor_by_gamm, "s(x2)", level = "1")
  expect_s3_class(sm, "mgcv.smooth")
  expect_equal(sm, su_m_factor_by_gamm[["gam"]][["smooth"]][[1L]])

  expect_error(get_by_smooth(su_m_factor_by, "s(x4)", level = "1"),
    "The requested smooth 's(x4)' is not a by smooth.",
    fixed = TRUE
  )

  expect_error(get_by_smooth(su_m_factor_by, "s(x2)"),
    "No value provided for argument 'level':",
    fixed = TRUE
  )

  expect_error(get_by_smooth(su_m_factor_by, "s(x2)", level = "4"),
    "Invalid 'level' for smooth 's(x2)'.",
    fixed = TRUE
  )
})

test_that("draw.gam works with select and parametric = TRUE", {
  plt <- draw(su_m_factor_by,
    select = "s(x2):fac1", parametric = TRUE,
    data = df_2_fac, envir = teardown_env()
  )

  skip_on_ci()
  expect_doppelganger(
    "draw.gam-user-select-and-parametric-true",
    plt
  )
})