Verbosity flags in R code

[AlexAxthelm]

https://ropensci.org/blog/2024/02/06/verbosity-control-packages/

I like the spirit of this, but disagree with the approach.

Namely, I like the logger approach for package developers (https://daroczig.github.io/logger/articles/r_packages.html), since that gives a very practical way to set different logging levels for different namespaces (packages).

For example, to only enable detailed logging from the workflow.factset package, with the rest of your environment at a higher level, you could have

logger::log_threshold("WARN") # ignore INFO, DEBUG, TRACE globally
logger::log_threshold("TRACE", namespace = "workflow.pacta") # Log everything from this package

This could be easily extended and built into a package infrastructure with something along the lines of

# Not tested
.onLoad <- function(libname, pkgname) {
  log_level <- coalesce(
    options(paste0("loglevel.", pkgname)),
    Sys.getenv(paste0("loglevel_", pkgname)),
    options("loglevel.pacta"),
    Sys.getenv("log_level_pacta"),
    options("loglevel"),
    Sys.getenv("log_level"),
    "INFO"
    logger::log_threshold(log_level, namespace = pkgname)
}

Which would look through a series of options ancd envvars (growing more generic as it looks) until it finds a valid logging level.

About the only thing that I'm not a fan of with logger is that it "doubles up" on the normal R output to stdout if you want ot retain use of the normal warnings and stop functions (for controlling execution), but it does allow for very informative messages (due to using glue by default), and can be combined with the base::warning() / base::stop() if you want:

if (foobar > 5) {
  logger::log_warn("argument \"foobar\" is only supported for values 5 and below. Current value: {foobar}.")
  warning("foobar too high") # could also add custom classes here
}