Make it easier to go into "debug mode"

[jennybc]

What would it take to make it easier to turn debugging messages on (and off) during development?

I think just a helper function would be nice versus manually setting an env var. Maybe it could default to the current package?

~~Then there's also the issue of turning it on, then needing to reload the package. That sounds a bit harder to smooth over, but maybe also possible?~~ I somehow thought I needed to install/restart/reload, but load_all() works, so nevermind.

[gaborcsardi]

Yeah, I agree that it needs to be improved.

[gaborcsardi]

So what I am trying to do is to have an html widget that serves as the log viewer, and debugme would send the log messages to the widget, instead of dumping them to the screen.

[krlmlr]

FWIW, the following zzz.R works for me. The debugme:::.onLoad() call isn't particularly pleasant, and a debugme_sitrep() would be great too:

.onLoad <- function(libname, pkgname) {
  # Necessary to re-parse environment variable
  debugme:::.onLoad(libname, pkgname)

  debugme::debugme()
  debug_info()
}

activate_debugme <- function(bangs = 2) {
  old_debugme <- remove_from_logging(get_debugme())
  old_debugme <- gsub("(.)$", "\\1,", old_debugme)

  my_debugme <- paste0(strrep("!", bangs), get_pkgname())

  set_debugme(paste0(old_debugme, my_debugme))
}

deactivate_debugme <- function() {
  new_debugme <- remove_from_logging(get_debugme())
  set_debugme(new_debugme)
}

get_debugme <- function() {
  Sys.getenv("DEBUGME")
}

set_debugme <- function(debugme) {
  Sys.setenv("DEBUGME" = debugme)
  message("DEBUGME=", debugme)
}

remove_from_logging <- function(spec) {
  spec <- gsub(paste0("!*", get_pkgname(), ""), "", spec)
  spec <- gsub(",,+", ",", spec)
  spec
}

debug_info <- function(pkgname) {
  "!DEBUG `get_pkgname()` loaded"
  "!!DEBUG Two bangs"
  "!!!DEBUG Three bangs"
  "!!!!DEBUG Four bangs"
}

get_pkgname <- function() {
  environmentName(topenv(environment()))
}

Here's an unreprex showing it in action. (I wonder why the bangs don't work, though.)

setwd(".../dynafilter")

devtools::load_all()
#> Loading dynafilter

activate_debugme()
#> DEBUGME=!!dynafilter
devtools::load_all()
#> Loading dynafilter
#> dynafilter dynafilter loaded 
#> dynafilter Two bangs +1ms 
#> dynafilter Three bangs +4ms 
#> dynafilter Four bangs +3ms

activate_debugme(bangs = 3)
#> DEBUGME=!!!dynafilter
devtools::load_all()
#> Loading dynafilter
#> dynafilter dynafilter loaded +509ms 
#> dynafilter Two bangs +4ms 
#> dynafilter Three bangs +5ms 
#> dynafilter Four bangs +4ms

deactivate_debugme()
#> DEBUGME=
devtools::load_all()
#> Loading dynafilter

^{Created on 2019-06-27 by the reprex package (v0.3.0)}

[r2evans]

Long time nothing heard ... I appreciate the simplicity of the package.

I think jennybc's suggestion to make it easier to toggle during development might still need some discussion. For instance, with an .onLoad of just debugme::debugme(), the first load_all works, but if I change the envvar and re-load_all, the new setting is not noticed. krlmlr's suggestion to use debugme:::.onLoad(.) works, though since I push my packages elsewhere, I run R's checks ... and it doesn't really appreciate the ::: use. As a workaround, I've found

.onLoad <- function(libname, pkgname) {
  get(".onLoad", asNamespace("debugme"))(libname, pkgname)
  debugme::debugme()
}

successfully hides it from R checks, though that's only being sneaky, not doing it "the right way".

Would it be a problem to change the recommended action to be

.onLoad <- function(libname, pkgname) {
  debugme::debugme(libname = libname, pkgname = pkgname)
}

or similar, employing whatever steps are required within debug:::.onLoad to re-examine the envvar?

---

Reprex: a package with:

testme <- function(...) {
  "!DEBUG This is a test of debug level `1`"
  "!!DEBUG This is a test of debug level `1+1`"
  "!!!DEBUG This is a test of debug level `sqrt(9)`"
  TRUE
}
.onLoad <- function(libname, pkgname) {
  debugme::debugme()
}

In a fresh R instance,

Sys.setenv(DEBUGME="!mypackage")
devtools::load_all("mypackage")
# Loading mypackage
# testme()
mypackage This is a test of debug level 1 
# [1] TRUE


Sys.setenv(DEBUGME="!!!mypackage")
devtools::load_all("mypackage")
# Loading mypackage
testme()
# mypackage This is a test of debug level 1 +26281ms 
# [1] TRUE

(detaching the package doesn't help, a little surprising to me.)

However, if I add debugme:::.onLoad (or my R-check-proof variant) and reload, it works:

### edit .onLoad()
devtools::load_all("mypackage")
# Loading mypackage
testme()
# mypackage This is a test of debug level 1 +21978ms 
# mypackage This is a test of debug level 2 +1ms 
# mypackage This is a test of debug level 3 +0ms 
# [1] TRUE

(Could this behavior be due to something in devtools::load_all?)

[krlmlr]

The PR makes it easier but doesn't resolve the original issue. We could add helpers for editing the environment variable, for sure. Here or in usethis?

@r2evans: The env var is now loaded in every debugme() call, one step closer.

[r2evans]

Honestly, I don't see the utility in helper functions for this, since it's simply controlled by an env var. I know some really like helper-funcs, though, I'm not opposed.

[gaborcsardi]

We could add some functions like this:

debug_package(package, level = 1)
undebug_package(package)
debug_status()

But I agree that it is not crucial.

[krlmlr]

Do you mind bringing in cli as a dependency for pretty output?

[gaborcsardi]

Do you mind bringing in cli as a dependency for pretty output?

Nope.

[r2evans]

Are you trying to minimize the footprint? That will include assertthat.

[gaborcsardi]

assertthat is very small and will be included in cli soon.

[gaborcsardi]

Otoh with cli we can drop crayon.