R/expect-vector.R

In testthat: Unit Testing for R

#' Do you expect a vector with this size and/or prototype?
#'
#' `expect_vector()` is a thin wrapper around [vctrs::vec_assert()], converting
#' the results of that function in to the expectations used by testthat. This
#' means that it used the vctrs of `ptype` (prototype) and `size`. See
#' details in <https://vctrs.r-lib.org/articles/type-size.html>
#'
#' @inheritParams expect_that
#' @param ptype (Optional) Vector prototype to test against. Should be a
#'   size-0 (empty) generalised vector.
#' @param size (Optional) Size to check for.
#' @export
#' @examplesIf requireNamespace("vctrs")
#' expect_vector(1:10, ptype = integer(), size = 10)
#' show_failure(expect_vector(1:10, ptype = integer(), size = 5))
#' show_failure(expect_vector(1:10, ptype = character(), size = 5))
expect_vector <- function(object, ptype = NULL, size = NULL) {
  check_installed("vctrs")
  check_number_whole(size, min = 0, allow_null = TRUE)
  act <- quasi_label(enquo(object))
  # vec_assert() automatically adds backticks so we hack out the ones
  # added by as_label()
  act$lab <- gsub("^`|`$", "", act$lab)

  failed <- FALSE
  withCallingHandlers(
    vctrs::vec_assert(act$val, ptype = ptype, size = size, arg = act$lab),
    vctrs_error_scalar_type = function(e) {
      failed <<- TRUE
      fail(e$message)
    },
    vctrs_error_assert = function(e) {
      failed <<- TRUE
      fail(e$message)
    }
  )

  if (!failed) {
    pass()
  }
  invisible(act$val)
}