R capture chisq.test() warning

warning-capture.r

chi_square <- function(x, p) {
  # chisq.test() wrapper that captures warning message and invocation string
  if (missing(p)) {
    expr <- substitute(chisq.test(x), list(x=x))
  }
  else {
    expr <- substitute(chisq.test(x, p=p, rescale.p = TRUE), list(x=x, p=p))
  }

  res <- tryCatch({
      eval(expr)
    },
    warning=function(w) {
      res <- eval(expr)
      res$warning <- w$message
      res
    }
  )

  res$cmd <- paste0(expr[1], "(", expr[2])
  if (!missing(p)) {
    res$cmd <- paste0(res$cmd, ", p=", expr[3], ", rescale.p = TRUE")
  }
  res$cmd <- paste0(res$cmd, ")")
  res
}

The above is unnecessary. The problem has been solved generally. In interactive R do:

> demo(error.catching)

So obvious, not sure how I missed it.