Check if two paths resolve to the same directory - r

Question

In Check if two file paths resolve to the same file the solution is to use normalizePath; however, this appears to not be definitive for directories:
td1 <- tempdir()
td2 <- paste0(td1, "/")
dir.exists(td1) && dir.exists(td2)
#> [1] TRUE
file.create(file.path(td1, "foo.txt"))
#> [1] TRUE
file.exists(file.path(td2, "foo.txt"))
#> [1] TRUE
normalizePath(td1) == normalizePath(td2)
#> [1] FALSE
sessionInfo()
#> R version 3.5.1 (2018-07-02)
#> Platform: x86_64-w64-mingw32/x64 (64-bit)
#> Running under: Windows 10 x64 (build 17134)
#>
#> Matrix products: default
#>
#> locale:
#> [1] LC_COLLATE=English_Australia.1252 LC_CTYPE=English_Australia.1252
#> [3] LC_MONETARY=English_Australia.1252 LC_NUMERIC=C
#> [5] LC_TIME=English_Australia.1252
#>
#> attached base packages:
#> [1] stats graphics grDevices utils datasets methods base
#>
#> loaded via a namespace (and not attached):
#> [1] compiler_3.5.1 backports_1.1.2 magrittr_1.5 rprojroot_1.3-2
#> [5] tools_3.5.1 htmltools_0.3.6 yaml_2.2.0 Rcpp_0.12.18
#> [9] stringi_1.1.7 rmarkdown_1.10 knitr_1.20 stringr_1.3.1
#> [13] digest_0.6.16 evaluate_0.11
Created on 2018-09-05 by the reprex package (v0.2.0).
Is there a method that is reliable (or more reliable) at identifying directories?

Answer 1

If you're open to using a package for this, I'm having a lot of success with the fs package for path operations that are robust across OSes. When it normalizes via fs::path_norm(), it will strip this trailing slash on Windows, for example.
td1 <- tempdir()
td2 <- paste0(td1, "/")
dir.exists(td1) && dir.exists(td2)
#> [1] TRUE
file.create(file.path(td1, "foo.txt"))
#> [1] TRUE
file.exists(file.path(td2, "foo.txt"))
#> [1] TRUE
normalizePath(td1) == normalizePath(td2)
#> [1] FALSE
library(fs)
path_norm(td1) == path_norm(td2)
#> [1] TRUE
sessionInfo()
#> R version 3.4.3 (2017-11-30)
#> Platform: x86_64-w64-mingw32/x64 (64-bit)
#> Running under: Windows 10 x64 (build 17134)
#>
#> Matrix products: default
#>
#> locale:
#> [1] LC_COLLATE=English_United States.1252
#> [2] LC_CTYPE=English_United States.1252
#> [3] LC_MONETARY=English_United States.1252
#> [4] LC_NUMERIC=C
#> [5] LC_TIME=English_United States.1252
#>
#> attached base packages:
#> [1] stats graphics grDevices utils datasets methods base
#>
#> loaded via a namespace (and not attached):
#> [1] compiler_3.4.3 backports_1.1.2 magrittr_1.5 rprojroot_1.3-2
#> [5] tools_3.4.3 htmltools_0.3.6 yaml_2.1.16 Rcpp_0.12.18
#> [9] stringi_1.1.6 rmarkdown_1.8 knitr_1.17 stringr_1.2.0
#> [13] digest_0.6.16 evaluate_0.10.1
Created on 2018-09-05 by the reprex package (v0.2.0).