R/merge_data_utils.R

In teal.transform: Functions for Extracting and Merging Data in the 'teal' Framework

#' Check if the merge function is valid
#'
#' @param merge_function (`character`) merge function name.
#'
#' @return Raises an error when check fails, otherwise, it returns `NULL`, invisibly.
#'
#' @keywords internal
#'
check_merge_function <- function(merge_function) {
  checkmate::assert_string(merge_function)
  stopifnot(length(intersect(methods::formalArgs(eval(rlang::parse_expr(merge_function))), c("x", "y", "by"))) == 3)
}