Test error when used with upcoming version of R6

[wch]

I'm in the process of releasing a new version of R6, and it results in an error with mlr3pipelines:

    ══ Failed tests ════════════════════════════════════════════════════════════════
    ── Error ('test_dictionary.R:251:3'): Cannot add pipeops with keys that invalidates the convenience for id incrementation ──
    Error in ``$.R6`(mlr_pipeops, clone)`: R6 class DictionaryPipeOp/Dictionary/R6 does not have slot 'clone'!
    Backtrace:
        ▆
     1. ├─mlr_pipeops$clone at test_dictionary.R:251:3
     2. └─global `$.R6`(mlr_pipeops, clone) at test_dictionary.R:251:3

See https://win-builder.r-project.org/incoming_pretest/R6_2.6.0_20250211_001904/reverseDependencies/summary.txt

Could you install the development version of R6 and address this issue? You can install with:

devtools::install_github('r-lib/R6', build_vignettes = FALSE)

This is unfortunately holding up the release of R6 on CRAN, so if you could release an updated version soon, I would appreciate it.

[mb706]

@advieser could you investigate this? In particular, also check where the warnings in the cited win-builder log come from. Probably some package that we ware using, but I'd be interested in which one and if we can switch this off.

[advieser]

OK, I got thinking about it, so I did it now, anyway :D (@mb706).

I don't see any warnings for us, except the test failure mentioned by @wch. All the other errors/warnings concern other packages as far as I can tell.

The test failure happens because we call $clone() on mlr_pipeops in test_dictionary.R although mlr_pipeops has cloneable=FALSE set during construction.
However, this has not been an issue until now, because mlr_pipeops still had a clone method since this was buggy on R6's side (As I understand it, if the super class, in our case Dictionary, was cloneable so were the subclasses). This seems to have been fixed with r-lib/R6#267 in the upcoming R6 version.

Assuming we want to keep our dictionaries non-cloneable, we should fix the test in which we call mlr_pipeops$clone() in test_dictionary.R which was added with 7c1aeab.:

mlr3pipelines/tests/testthat/test_dictionary.R

Lines 248 to 251 in 11cdde6

	test_that("Cannot add pipeops with keys that invalidates the convenience for id incrementation", {
	copy = mlr_pipeops$clone(deep = TRUE)
	expect_error(copy$add("name_1", PipeOp), regexp = "grepl")
	})

To avoid cloning, we could remove the added entry again in cases where the error actually did not occur:

test_that("Cannot add pipeops with keys that invalidates the convenience for id incrementation", {
  expect_error(mlr_pipeops$add("name_1", PipeOp), regexp = "grepl")
  if ("name_1" %in% mlr_pipeops$keys()) {
    mlr_pipeops$remove("name_1")
  }
})

Thoughts and/or better solutions?

[wch]

Just an update: CRAN has decided let R6 through, so this issue is no longer holding up the R6 release. But that does mean that mlr3pipelines will probably start getting errors on CRAN when they run tests with the new version of R6.