Attempting to use options package.

[meztez]

Pending a doc ordering issue in options package.

dgkf/options#7

PR task list:

• Update NEWS
• Add tests
• Update documentation with devtools::document()

[meztez]

I'm thinking using the options package would maybe open up an attack vector, because of this line here:
https://github.com/dgkf/options/blob/a2c110229f844de49b3dbb56bb0a19542b92899a/R/envvars.R#L168

I'm going to ice this one for now.

[schloerke]

@meztez Currently, envvar_eval_or_raw is a default parameter to options::option_spec(). We could easily supply a safe version when defining the plumber option spec and we'd be fine.

[schloerke]

The option_spec() handles the extra args supplied to define_option.character().

So we could use a helper function to define the options (setting the envvar_fn value for every option):

# Copied from https://github.com/dgkf/options/blob/a2c1102/R/envvars.R#L1-L4
# Sets up pretty printing
fn_with_desc <- function(f, desc) {
  attr(f, "desc") <- desc
  f
}
# Keep sys env var as raw string only
plumber_envvar_raw <- fn_with_desc(
  function(raw, name, ...) {
    raw
  },
  "string"
)
define_plumber_option <- function(...) {
  options::define_option(
    ...,
    envvar_fn = plumber_envvar_raw
  )
}

# Ex usage
define_plumber_option(
  option = "port",
  default = NULL,
  desc = paste(
    "Port Plumber will attempt to use to start http server.",
    "If the port is already in use, server will not be able to start."
  )
)

[meztez]

Noted, still have to figure out what to do with options_plumber, return values. Probably do not want to change the behavior. Options does not have an opt<- equivalent yet. Integrating httpproblems at the moment.