R/coalesce_join.R

In malcalakovalski/fim: Fiscal Impact Measure

coalesce_join <- function(x, y, 
                          by = NULL, suffix = c(".x", ".y"), 
                          join = dplyr::full_join, ...) {
  joined <- join(x, y, by = by, suffix = suffix, ...)
  # names of desired output
  cols <- union(names(x), names(y))
  
  to_coalesce <- names(joined)[!names(joined) %in% cols]
  suffix_used <- suffix[ifelse(endsWith(to_coalesce, suffix[1]), 1, 2)]
  # remove suffixes and deduplicate
  to_coalesce <- unique(substr(
    to_coalesce, 
    1, 
    nchar(to_coalesce) - nchar(suffix_used)
  ))
  
  coalesced <- purrr::map_dfc(to_coalesce, ~dplyr::coalesce(
    joined[[paste0(.x, suffix[1])]], 
    joined[[paste0(.x, suffix[2])]]
  ))
  names(coalesced) <- to_coalesce
  
  dplyr::bind_cols(joined, coalesced)[cols]
}