tests/testthat/test-extract_fin_year.R

In Health-SocialCare-Scotland/phimethods: Standard Methods for Use in Public Health Scotland

test_that("Date is assigned to the correct financial year", {
  expect_equal(extract_fin_year(as.Date("20120331", "%Y%m%d")), "2011/12")
  expect_equal(extract_fin_year(as.Date("20120401", "%Y%m%d")), "2012/13")
  expect_equal(extract_fin_year(as.POSIXct("20190104", format = "%Y%m%d")), "2018/19")
})

test_that("Date is accepted in various formats", {
  expect_equal(extract_fin_year(as.Date("17111993", "%d%m%Y")), "1993/94")
  expect_equal(extract_fin_year(as.Date("19980404", "%Y%m%d")), "1998/99")
  expect_equal(extract_fin_year(as.Date("21-Jan-2017", "%d-%B-%Y")), "2016/17")
  expect_equal(extract_fin_year(as.POSIXct("20181401", format = "%Y%d%m")), "2017/18")
  expect_equal(extract_fin_year(lubridate::dmy(29102019)), "2019/20")
})

test_that("Non-date formats produce an error", {
  expect_error(extract_fin_year("28102019"))
  expect_error(extract_fin_year("28-Oct-2019"))
  expect_error(extract_fin_year(as.numeric("28102019")))
  expect_error(extract_fin_year(as.factor("28-Oct-2019")))
})

test_that("NAs are handled correctly", {
  expect_equal(extract_fin_year(c(lubridate::dmy(05012020), NA)), c("2019/20", NA))
})

test_that("YYYY/YY format applied correctly", {
  expect_equal(
    extract_fin_year(c(lubridate::dmy(NA, "01/April/1999"), NA)),
    c(NA, "1999/00", NA)
  )
  expect_equal(
    extract_fin_year(c(lubridate::dmy(NA, "01/April/2000"), NA)),
    c(NA, "2000/01", NA)
  )
  expect_equal(
    extract_fin_year(c(lubridate::dmy(NA, "01/April/2001"), NA)),
    c(NA, "2001/02", NA)
  )
  expect_equal(
    extract_fin_year(c(lubridate::dmy(NA, "31/March/1999"), NA)),
    c(NA, "1998/99", NA)
  )
  expect_equal(
    extract_fin_year(c(lubridate::dmy(NA, "31/March/2000"), NA)),
    c(NA, "1999/00", NA)
  )
  expect_equal(
    extract_fin_year(c(lubridate::dmy(NA, "31/March/2001"), NA)),
    c(NA, "2000/01", NA)
  )
  expect_equal(
    extract_fin_year(c(lubridate::dmy(NA, "01/December/1999"), NA)),
    c(NA, "1999/00", NA)
  )
  expect_equal(
    extract_fin_year(c(lubridate::dmy(NA, "01/December/2000"), NA)),
    c(NA, "2000/01", NA)
  )
  expect_equal(
    extract_fin_year(c(lubridate::dmy(NA, "01/December/2999"), NA)),
    c(NA, "2999/00", NA)
  )
  expect_equal(
    extract_fin_year(c(lubridate::dmy(NA, "01/December/3000"), NA)),
    c(NA, "3000/01", NA)
  )

  expect_equal(
    extract_fin_year(
      lubridate::as_datetime(
        c(lubridate::dmy(NA, "01/April/1999"), NA)
      )
    ),
    c(NA, "1999/00", NA)
  )

  expect_equal(
    extract_fin_year(
      lubridate::as_datetime(
        c(lubridate::dmy(NA, "01/December/2000"), NA)
      )
    ),
    c(NA, "2000/01", NA)
  )

  expect_equal(
    extract_fin_year(
      lubridate::as_datetime(
        c(lubridate::dmy(NA, "01/April/0001"), NA)
      )
    ),
    c(NA, "0001/02", NA)
  )
})

test_that("Correct outputs", {
  expect_snapshot({
    start <- lubridate::make_date(1999, 4, 1)
    end <- lubridate::make_date(2100, 3, 31)
    dates <- seq(start, end, by = "day")

    df <- data.frame(
      date = dates,
      fin_year = extract_fin_year(dates)
    )

    dplyr::summarise(df,
      first_date = min(date),
      last_date = max(date),
      days = dplyr::n(),
      .by = fin_year
    )
  })
})