# Set number of data.table threads to 1
data.table::setDTthreads(threads = 2L)
# Set number of collapse threads to 1
collapse::set_collapse(nthreads = 1L)

testthat::test_that("Expect error", {
  testthat::expect_error(age_years(Inf))
  testthat::expect_error(age_years(-Inf))
  testthat::expect_error(age_years(NaN))
  testthat::expect_error(age_years(NULL))
  testthat::expect_error(age_years(Sys.Date(), end = "01-01-2000"))
})

testthat::test_that("Expect zero length vector", {
  empty_values <- list(as.POSIXlt(numeric(0)),
                       lubridate::Date(0),
                       lubridate::POSIXct(0))
  testthat::expect_identical(lapply(empty_values, function(x) age_years(x)),
                             list(integer(0), integer(0), integer(0)))
})

testthat::test_that("Expect NA", {
  testthat::expect_identical(age_years(lubridate::NA_Date_),
                             NA_integer_)
  testthat::expect_identical(age_years(lubridate::NA_POSIXct_),
                             NA_integer_)
  testthat::expect_identical(age_years(as.POSIXlt(NA)),
                             NA_integer_)
})

testthat::test_that("Leap year", {
  leap1 <- lubridate::dmy("29-02-2020")
  leap2 <- lubridate::dmy("28-02-2021")
  leap3 <- lubridate::dmy("01-03-2021")
  testthat::expect_identical(age_years(leap1, leap2), 0L)
  testthat::expect_identical(age_years(leap1, leap3), 1L)
})