tests/testthat/test-letter-number-conversion.R

In jennybc/cellranger: Translate Spreadsheet Cell Ranges to Rows and Columns

context("letter <--> number conversion")

test_that("Column letter converts to correct column number", {
  expect_equal(letter_to_num("A"), 1L)
  expect_equal(letter_to_num("AB"), 28L)
  expect_equal(
    letter_to_num(
      c("A", "AH", NA, "", "ABD", "XFD")
    ),
    c(1L, 34L, NA, NA, 732L, 16384L)
  )

  expect_error(letter_to_num(1:5))
  expect_error(letter_to_num(factor(LETTERS)))
})

test_that("Column number converts to correct column letter", {
  expect_equal(num_to_letter(1), "A")
  expect_equal(num_to_letter(28), "AB")
  expect_equal(
    num_to_letter(
      c(34, NA, 0, -4, 732, 16384, 4.8)
    ),
    c("AH", NA, NA, NA, "ABD", "XFD", "D")
  )

  expect_error(num_to_letter("hi there"))
  expect_error(num_to_letter("100"))
})