Conversion from binary to decimal and reverse

I try with a friend to code a general function to convert between binary and decimal inputs.

conversion <- function(number, direction = c("to_dec", "to_bin")) {                           
  direction <- match.arg(direction)                                                                    
  if(grepl("[2-9]", as.character(number), ""[[1L]]) &                 
     direction == "to_dec" &typeof(number)=='character') {
    warning(paste0("Non-binary digits in number. Argument direction changed.,Continue with conversion to binary number."))
    direction <- "to_dec" } else {                                                          
      stop(paste0(                                                                                   
        "Binary number not supplied as string. Leading 0s get lost.\n", "Stop conversion."))
    }
  if(direction == "to_dec") {
    u <- as.numeric(strsplit(as.character(number), "")[[1L]]) 
    ret <- 0L
    u <- rev(u)
    for(i in 1:length(u)){
      ret <- ret + u[i] * 2L^(i - 1L) }
    ret <- as.integer(ret) } else {
      u <- as.integer(number)
      ret <- vector(mode = "integer") while (u > 1) {
        ret <- c(ret, u%%2)
        floor(u / 2) }
      ret <- paste(ret) 
    }
  ret
}

That's how the code looks like. However we are not too sure about the if statements and thus get some errors. If someone has an input idea, let us know.