resubmission that hopefully fixes sort order of files in cache on systems with low-accuracy timestamp

Author: Stefan Fleck

DESCRIPTION

@@ -1,7 +1,7 @@
 Type: Package
 Package: rotor
 Title: Log Rotation and Conditional Backups
-Version: 0.3.1
+Version: 0.3.2
 Authors@R: 
     person(given = "Stefan",
            family = "Fleck",

R/Cache.R

@@ -333,7 +333,8 @@ Cache <- R6::R6Class(
       )
       row.names(res) <- NULL
 
-      res[order(res$mtime), ]
+      assert(!is.null(res$mtime))
+      res[order(res$mtime, res$key), ]
     },
 
     size = function(){

cran-comments.md

@@ -10,21 +10,12 @@
 
 0 errors | 0 warnings | 0 notes
 
-* fixes time zone related issue in `Cache$prune()` that causes macOS tests to fail
-* more robust cleanup of temporary files between some tests
-* resubmission that improves one test where 
-  `https://cran.r-project.org/web/checks/check_results_rotor.html` shows an
-  error that I could not reproduce on any machine available on rhub. 
-  Hopefully the test succeedes now, but if not it will give me more useful 
-  debug information for another resubmission.
+Sorry for the many resubmissions. This package currently has an issue that
+only to occur on macOS. It does not occur on the same macOS version available
+on Rhub. 
 
-
-Notes:
-
-There was a timezone related issue that only occured on macos. I fixed it and
-was able to test it on macOS 10.13.6 High Sierra with R-release (but not devel)
-on Rhub.
-
-I could not reproduce the other errors; however, it looks as if they were caused
-by improperly cleaned-up temporary files between failing tests. I made the
-cleanup code a bit more robust and hope the problem is fixed now.
+My current theory is that the error is caused by the accuracy of the
+'mtime' filestamp, which is linked to the file system the machine uses. 
+I implemented a workaround under that assumption, but I cannot be 100% sure 
+that this fixes that error. If the error still persists... could you please
+inform me which file system you use on r-release-macos-x86_64?

tests/testthat/test_Cache.R

@@ -70,9 +70,7 @@ test_that("pruning works by number of files works", {
   # be added to the cache once
   cache <- Cache$new(td, hashfun = function(x) uuid::UUIDgenerate())
   k1 <- cache$push(iris)
-  Sys.sleep(1)
   k2 <- cache$push(letters)
-  Sys.sleep(1)
   k3 <- cache$push(cars)
   expect_identical(cache$n, 3L)
 
@@ -81,7 +79,6 @@ test_that("pruning works by number of files works", {
   expect_identical(cache$files$key[[3]], k3)
 
   cache$prune(max_files = 2)
-  cache$files
   expect_identical(cache$read(cache$files$key[[1]]), letters)
   expect_identical(cache$read(cache$files$key[[2]]), cars)
   cache$purge()