get_cache doesn't actually get the cache at the path provided

[kendonB]

Prework

• Read and abide by drake's code of conduct.
• Search for duplicates among the existing issues, both open and closed.
• Advanced users: verify that the bug still persists in the current development version (i.e. remotes::install_github("ropensci/drake")) and mention the SHA-1 hash of the Git commit you install.

Description

get_cache finds .drake even when the exact path of an adjacent cache is given.

Reproducible example

library(drake)
cache = new_cache(".test")
test_plan = drake_plan(
  dot_test = 1
)
make(test_plan, cache = cache)
#> target dot_test
dr_plan = drake_plan(
  dot_drake = 1
)
make(dr_plan)
#> target dot_drake
# finds .drake
cached(cache = get_cache(".test"))
#> [1] "dot_drake"
# works
cached(cache = cache)
#> [1] "dot_test"
# works
cached(cache = this_cache(".test"))
#> Warning: this_cache() in drake is deprecated. Use get_cache() or
#> storr::storr_rds() instead.
#> [1] "dot_test"

^{Created on 2019-05-26 by the reprex package (v0.3.0)}

Expected output

library(drake)
cache = new_cache(".test")
test_plan = drake_plan(
  dot_test = 1
)
make(test_plan, cache = cache)
#> target dot_test
dr_plan = drake_plan(
  dot_drake = 1
)
make(dr_plan)
#> target dot_drake
# works
cached(cache = get_cache(".test"))
#> [1] "dot_test"
# works
cached(cache = cache)
#> [1] "dot_test"
# works
cached(cache = this_cache(".test"))
#> Warning: this_cache() in drake is deprecated. Use get_cache() or
#> storr::storr_rds() instead.
#> [1] "dot_test"

^{Created on 2019-05-26 by the reprex package (v0.3.0)}

[wlandau]

Thanks for the nudge. I regret the awkward design of get_cache(), and I think we should deprecate it in favor of a better-behaved drake_cache() function. A PR is forthcoming.

[wlandau]

Fixed via #884.