test_that("returns dataframe", {
  df_timelines <- butterfly::timeline_group(
    forestprecipitation$january,
    datetime_variable = "time",
    expected_lag = 1
  )

  expect_s3_class(
    df_timelines,
    "data.frame"
  )

  expect_named(
    df_timelines,
    c(
      "time",
      "rainfall_mm",
      "timelag",
      "timeline_group"
    )
  )
})

test_that("returns expected number of sequences", {
  df_timelines <- butterfly::timeline_group(
    forestprecipitation$january,
    datetime_variable = "time",
    expected_lag = 1
  )

  expect_equal(
    length(
      unique(
        df_timelines$timeline_group
      )
    ),
    1
  )

  df_reset <- butterfly::timeline_group(
    forestprecipitation$february,
    datetime_variable = "time",
    expected_lag = 1
  )

  expect_equal(
    length(
      unique(
        df_reset$timeline_group
      )
    ),
    2
  )
})

test_that("expected errors work", {
  expect_error(
    df_timelines <- butterfly::timeline_group(
      forestprecipitation$january,
      datetime_variable = "foo",
      expected_lag = 1
    ),
    "`datetime_variable` must be present in `df_current`"
  )

  df_timelines <- butterfly::timeline_group(
    forestprecipitation$january,
    datetime_variable = "time",
    expected_lag = 1
  )

  df_timelines$time <- as.character(df_timelines$time)

  expect_error(
    df_timelines <- butterfly::timeline_group(
      df_timelines,
      datetime_variable = "time",
      expected_lag = 1
    ),
    "`datetime_variable` must be class of POSIXct, POSIXlt, POSIXt, Date"
  )

})