Generate all combinations with named and unnamed arguments for a call

generate.R

generate <- function(named, unnamed, used = exprs()) {
  if (length(named) == 0 && length(unnamed) == 0) {
    return(deparse(call2("check_api", !!!used), width.cutoff = 500))
  }
  
  out <- character()
  
  for (i in seq_along(named)) {
    out <- c(out, generate(named[-i], unnamed, c(used, named[i])))
  }
  
  if (length(unnamed) > 0) {
    out <- c(out, generate(named, unnamed[-1], c(used, unnamed[[1]])))
  }
  
  out
}

args <- exprs(
  dm = dm, 
  table = a,
  b > 1,
)

generate_named <- function(args, named = list(), unnamed = list()) {
  if (length(args) == 0) {
    out <- generate(named, unnamed)
    writeLines(c(
      "expect_same(",
      paste0("  ", out, collapse = ",\n"),
      ")"
    ))
    return(invisible())
  }
  
  generate_named(args[-1], named, c(unnamed, args[[1]]))
  if (names2(args)[[1]] != "") {
    generate_named(args[-1], c(named, args[1]), unnamed)
  }
  invisible()
}

generate_named(args)