align.md
In ivs: Interval Vectors

`locations` is validated

Code
  (expect_error(iv_align(1, 2, locations = 1)))
Output
  <error/rlang_error>
  Error in `iv_align()`:
  ! `locations` must be a data frame.
Code
  (expect_error(iv_align(1, 2, locations = data_frame())))
Output
  <error/rlang_error>
  Error in `iv_align()`:
  ! `locations` must be a two column data frame.
Code
  (expect_error(iv_align(1, 2, locations = data_frame(x = 1, haystack = 2))))
Output
  <error/rlang_error>
  Error in `iv_align()`:
  ! `locations` must have a column named "needles".
Code
  (expect_error(iv_align(1, 2, locations = data_frame(needles = 1, x = 2))))
Output
  <error/rlang_error>
  Error in `iv_align()`:
  ! `locations` must have a column named "haystack".
Code
  (expect_error(iv_align(1, 2, locations = data_frame(needles = 1, haystack = 2L)))
  )
Output
  <error/rlang_error>
  Error in `iv_align()`:
  ! `locations$needles` must be an integer vector.
Code
  (expect_error(iv_align(1, 2, locations = data_frame(needles = 1L, haystack = 2)))
  )
Output
  <error/rlang_error>
  Error in `iv_align()`:
  ! `locations$haystack` must be an integer vector.