diff --git a/ChangeLog.md b/ChangeLog.md
index 301e9a5..05cf296 100644
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -2,6 +2,19 @@ ChangeLog for SamsElves Package
 
 --------------------------------------------------------------------------------
 
+## 2024-09-30 v.0.3.4
+
+- added:
+  - utils_io.R from ihme.covid package
+    - `make_new_output_dir` - create a version-incremented run-date folder based on a 'YYYY_MM_DD.VV' run-date folder structure
+      - supported by `get_latest_output_date_index` and `get_new_output_dir`
+    - `get_latest_output_dir` - get the latest output directory based on a 'YYYY_MM_DD.VV' run-date folder structure
+    - added tests, updated deprecated methods
+- documented:
+  - some previously undocumented helper functions for various methods (not exported)
+
+
+
 ## 2024-09-23 v.0.3.3
 
 - updated:
@@ -13,6 +26,7 @@ ChangeLog for SamsElves Package
     - retains original file extension
 
 
+
 ## 2024-09-19 v.0.3.2
 
 - updated:
@@ -20,6 +34,8 @@ ChangeLog for SamsElves Package
     - now includes option for custom csv reading function since `data.table::fread` can have quotation-doubling issues
     - also includes `...` arg to pass additional user-desired args to the reader function (works for any underlying reader function)
 
+
+
 ## 2024-09-18
 
 - deprecated:
@@ -34,6 +50,7 @@ ChangeLog for SamsElves Package
     - now includes a selection of sessionInfo for R version, package versions, etc. for pipeline provenance
 
 
+
 ## 2024-09-06
 
 - added:
@@ -42,6 +59,8 @@ ChangeLog for SamsElves Package
   - `submit_job` & `submit_job_array`
     - added console-style log option (combine stderr and stdout)
 
+
+
 ## 2023-12-04
 
 - deprecated: 
diff --git a/DESCRIPTION b/DESCRIPTION
index 316e474..639fcad 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -1,7 +1,7 @@
 Type: Package
 Package: SamsElves
 Title: Helper functions for the data science at IHME
-Version: 0.3.3
+Version: 0.3.4
 Author: Sam Byrne (ssbyrne@uw.edu)
 Description: Helper functions for the data science at IHME
 License: none
diff --git a/NAMESPACE b/NAMESPACE
index d1930ab..659171c 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -13,10 +13,14 @@ export(datetime_stamp)
 export(extract_sessionInfo)
 export(extract_submission_commands)
 export(find_file_extension)
+export(get_latest_output_date_index)
+export(get_latest_output_dir)
+export(get_new_output_dir)
 export(increment_file_version)
 export(is_empty)
 export(is_sequential_int_vec)
 export(make_directory)
+export(make_new_output_dir)
 export(make_versioned_dir)
 export(msg_multiline)
 export(msg_prt)
diff --git a/R/children_of_parents.R b/R/children_of_parents.R
index 470c412..353df96 100644
--- a/R/children_of_parents.R
+++ b/R/children_of_parents.R
@@ -68,7 +68,13 @@ children_of_parents <- function(
 
 }
 
-#' @description Helper function for children_of_parents.
+#' Helper function for children_of_parents.
+#'
+#' @param parent_loc_ids [int] ihme location ids
+#' @param output [character] output options
+#' @param hierarchy [data.table] ihme location hierarchy
+#'
+#' @return [none] stop on failure
 validate_children_of_parents_inputs = function(parent_loc_ids, output, hierarchy){
   # Check for valid parent_locs_ids type
   if (!is.vector(parent_loc_ids) | !is.numeric(parent_loc_ids)) {
@@ -87,14 +93,15 @@ validate_children_of_parents_inputs = function(parent_loc_ids, output, hierarchy
   }
 }
 
-#' @description Helper function for children_of_parents.
+#' Helper function for children_of_parents.
+#'
 #' Given a single parent_id and a path_to_top_parent,
 #' returns TRUE if that parent_id is in the path.
 #'
 #' @param parent_id [int] Location ID of parent to test
 #' @param path_to_top_parent [character] String of path to top parent from hierarchy
 #'
-#' @return boolean
+#' @return [lgl] TRUE if parent_id is in path_to_top_parent
 is_child_of_parent = function(parent_id, path_to_top_parent){
   path_to_top_parent = as.integer(unlist(strsplit(path_to_top_parent, ",")))
   return(parent_id %in% path_to_top_parent)
diff --git a/R/parents_of_children.R b/R/parents_of_children.R
index b0a1fc7..be9db5e 100644
--- a/R/parents_of_children.R
+++ b/R/parents_of_children.R
@@ -53,7 +53,13 @@ parent_of_child <- function(
        parent_level %i", child_location_id, head(hierarchy), parent_level))
 }
 
-#' @description Helper function to validate inputs to function
+#' Helper function to validate inputs to function
+#'
+#' @param child_location_id [int] ihme location_id
+#' @param hierarchy [data.table] ihme location hierarchy
+#' @param parent_level [int] ihme location level
+#'
+#' @return [none] stop on failure
 validate_parents_of_children_inputs <- function(child_location_id, hierarchy, parent_level){
   # Check for valid parent_level
   if(length(parent_level) != 1){
diff --git a/R/utils_io.R b/R/utils_io.R
index a74d8b5..bbca015 100644
--- a/R/utils_io.R
+++ b/R/utils_io.R
@@ -115,9 +115,9 @@ save_file <- function(object, f_path, forbid_overwrite = TRUE, verbose = FALSE){
 
 #' Read a file of an arbitrary type
 #'
-#' @param path_to_file [chr] full path with extenstion
+#' @param path_to_file [chr] full path with extension
 #' @param verbose [lgl] noisy or quiet function?
-#' @param csv_opt [chr] namespaced function call for csv reads (default `"data.table::fread"`)
+#' @param csv_opt [chr] name spaced function call for csv reads (default `"data.table::fread"`)
 #' @param ... [any] additional arguments to pass to the reader function
 #'
 #' @return [file] an object of appropriate file type
@@ -189,3 +189,112 @@ increment_file_version <- function(outpath){
 
   return(outpath_new)
 }
+
+
+#' get the latest index for given an output dir and a date
+#'
+#' directories are assumed to be named in YYYY_MM_DD.VV format with sane
+#' year/month/date/version values.
+#'
+#' @param dir [chr] path to directory with versioned dirs
+#' @param date [chr] character in be YYYY_MM_DD format
+#'
+#' @return [dbl] largest version in directory tree or 0 if there are no version OR
+#' the directory tree does not exist
+#' @export
+#'
+#' @examples
+#' get_latest_output_date_index("tests/testthat/fixtures/versioned-dirs/nested/1999_09_09", date = "1999_09_09") # expect 2
+get_latest_output_date_index <- function(dir, date) {
+  currentfolders <- list.files(dir)
+
+  # subset to date
+  pat <- sprintf("^%s[.]\\d{2}$", date)
+  date_dirs <- grep(pat, currentfolders, value = TRUE)
+
+  if (length(date_dirs) == 0) {
+    return(0)
+  }
+
+  # get the index after day
+  date_list <- strsplit(date_dirs, "[.]")
+
+  inds <- unlist(lapply(date_list, function(x) x[2]))
+  if (is.na(max(inds, na.rm = T))) inds <- 0
+
+  return(max(as.numeric(inds)))
+}
+
+
+#' Find the latest output directory with format YYYY_MM_DD.VV
+#'
+#' @param root [chr] path to root of output results
+#'
+#' @return [chr] path to latest output directory
+#' @export
+#'
+#' @examples
+#' get_latest_output_dir("tests/testthat/fixtures/versioned-dirs/nested/1999_09_09") # expect "tests/testthat/fixtures/versioned-dirs/nested/1999_09_09/1999_09_09.02"
+get_latest_output_dir <- function(root) {
+  if (!dir.exists(root)) {
+    stop(sprintf("root %s does not exist", root))
+  }
+  raw <- list.dirs(root, full.names = FALSE, recursive = FALSE)
+  valid.idx <- grep("^\\d{4}_\\d{2}_\\d{2}[.]\\d{2}$", raw)
+  if (length(valid.idx) == 0) {
+    stop(sprintf("No YYYY_MM_DD.VV directories in %s", root))
+  }
+  return(file.path(root, max(raw[valid.idx])))
+}
+
+
+
+#' Increment a new output folder date-version
+#'
+#' Get a new directory path, but don't make it
+#'
+#' @param root [chr] path to root of output results
+#' @param date [chr] character date in form of "YYYY_MM_DD" or "today". "today" will be interpreted as today's date.
+#'
+#' @return [chr] path to new output direcctory
+#' @export
+#'
+#' @examples
+#' get_new_output_dir(root = tempdir(), date = "today")
+get_new_output_dir <- function(root, date){
+  if (date == "today") {
+    date <- format(Sys.Date(), "%Y_%m_%d")
+  }
+  cur.version <- get_latest_output_date_index(root, date = date)
+
+  dir.name <- sprintf("%s.%02i", date, cur.version + 1)
+  dir.path <- file.path(root, dir.name)
+  return(dir.path)
+}
+
+
+#' Get output directory for results to save in
+#'
+#' Returns an appropriate path to save results in, creating it if necessary.
+#'
+#' @param root [chr] path to root of output results
+#' @param date [chr] character date in form of "YYYY_MM_DD" or "today". "today" will be interpreted as today's date.
+#'
+#' @return [chr] path to new output directory
+#' @export
+#'
+#' @examples
+#' \dontrun{
+#' make_new_output_dir("my/root/folder", date = "today")
+#' }
+make_new_output_dir <- function(root, date) {
+  dir.path <- get_new_output_dir(root, date)
+  if (!dir.exists(dir.path)) {
+    # handle quirk with singularity image default umask
+    old.umask <- Sys.umask()
+    Sys.umask("002")
+    dir.create(dir.path, showWarnings = FALSE, recursive = TRUE, mode = "0777")
+    Sys.umask(old.umask)
+  }
+  return(dir.path)
+}
diff --git a/R/wait_on_slurm_job_id.R b/R/wait_on_slurm_job_id.R
index e30a973..629fa7d 100644
--- a/R/wait_on_slurm_job_id.R
+++ b/R/wait_on_slurm_job_id.R
@@ -214,12 +214,14 @@ wait_on_slurm_job_id <-
     print(paste0("Job(s) ", job_id_msg, " no longer PENDING, RUNNING, or FAILED. Time elapsed: ", job.runtime, " seconds"))
   }
 
+#' Helper function for wait_on_slurm_job_id - how do you want jobs to break and display user messages?
+#'
 #' @param cmd_fail [chr]
 #' @param cmd_fail_feedback [chr]
 #' @param job_id_regex_raw [regex]
 #' @param filter_by [chr]
 #'
-#' @description Helper function for wait_on_slurm_job_id - how do you want jobs to break and display user messages?
+#' @return [none] stop on failure
 break_for_failed_jobs <-
   function(
     cmd_fail,
diff --git a/man/break_for_failed_jobs.Rd b/man/break_for_failed_jobs.Rd
new file mode 100644
index 0000000..6f8592a
--- /dev/null
+++ b/man/break_for_failed_jobs.Rd
@@ -0,0 +1,23 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/wait_on_slurm_job_id.R
+\name{break_for_failed_jobs}
+\alias{break_for_failed_jobs}
+\title{Helper function for wait_on_slurm_job_id - how do you want jobs to break and display user messages?}
+\usage{
+break_for_failed_jobs(cmd_fail, cmd_fail_feedback, job_id_regex_raw, filter_by)
+}
+\arguments{
+\item{cmd_fail}{[chr]}
+
+\item{cmd_fail_feedback}{[chr]}
+
+\item{job_id_regex_raw}{[regex]}
+
+\item{filter_by}{[chr]}
+}
+\value{
+[none] stop on failure
+}
+\description{
+Helper function for wait_on_slurm_job_id - how do you want jobs to break and display user messages?
+}
diff --git a/man/get_latest_output_date_index.Rd b/man/get_latest_output_date_index.Rd
index ac1d8fa..5f63218 100644
--- a/man/get_latest_output_date_index.Rd
+++ b/man/get_latest_output_date_index.Rd
@@ -1,21 +1,32 @@
 % Generated by roxygen2: do not edit by hand
-% Please edit documentation in R/make_versioned_dir.R
+% Please edit documentation in R/make_versioned_dir.R, R/utils_io.R
 \name{get_latest_output_date_index}
 \alias{get_latest_output_date_index}
 \title{get the latest index for given an output dir and a date}
 \usage{
+get_latest_output_date_index(dir, date)
+
 get_latest_output_date_index(dir, date)
 }
 \arguments{
-\item{dir}{path to directory with versioned dirs}
+\item{dir}{[chr] path to directory with versioned dirs}
 
-\item{date}{character in YYYY_MM_DD format}
+\item{date}{[chr] character in be YYYY_MM_DD format}
 }
 \value{
 largest version in directory tree or 0 if there are no version OR
 the directory tree does not exist
+
+[dbl] largest version in directory tree or 0 if there are no version OR
+the directory tree does not exist
 }
 \description{
 directories are assumed to be named in YYYY_MM_DD.VV format with sane
 year/month/date/version values.
+
+directories are assumed to be named in YYYY_MM_DD.VV format with sane
+year/month/date/version values.
+}
+\examples{
+get_latest_output_date_index("tests/testthat/fixtures/versioned-dirs/nested/1999_09_09", date = "1999_09_09") # expect 2
 }
diff --git a/man/get_latest_output_dir.Rd b/man/get_latest_output_dir.Rd
new file mode 100644
index 0000000..bf4668e
--- /dev/null
+++ b/man/get_latest_output_dir.Rd
@@ -0,0 +1,20 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/utils_io.R
+\name{get_latest_output_dir}
+\alias{get_latest_output_dir}
+\title{Find the latest output directory with format YYYY_MM_DD.VV}
+\usage{
+get_latest_output_dir(root)
+}
+\arguments{
+\item{root}{[chr] path to root of output results}
+}
+\value{
+[chr] path to latest output directory
+}
+\description{
+Find the latest output directory with format YYYY_MM_DD.VV
+}
+\examples{
+get_latest_output_dir("tests/testthat/fixtures/versioned-dirs/nested/1999_09_09") # expect "tests/testthat/fixtures/versioned-dirs/nested/1999_09_09/1999_09_09.02"
+}
diff --git a/man/get_new_output_dir.Rd b/man/get_new_output_dir.Rd
new file mode 100644
index 0000000..9e7ca7f
--- /dev/null
+++ b/man/get_new_output_dir.Rd
@@ -0,0 +1,22 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/utils_io.R
+\name{get_new_output_dir}
+\alias{get_new_output_dir}
+\title{Increment a new output folder date-version}
+\usage{
+get_new_output_dir(root, date)
+}
+\arguments{
+\item{root}{[chr] path to root of output results}
+
+\item{date}{[chr] character date in form of "YYYY_MM_DD" or "today". "today" will be interpreted as today's date.}
+}
+\value{
+[chr] path to new output direcctory
+}
+\description{
+Get a new directory path, but don't make it
+}
+\examples{
+get_new_output_dir(root = tempdir(), date = "today")
+}
diff --git a/man/is_child_of_parent.Rd b/man/is_child_of_parent.Rd
new file mode 100644
index 0000000..c249809
--- /dev/null
+++ b/man/is_child_of_parent.Rd
@@ -0,0 +1,20 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/children_of_parents.R
+\name{is_child_of_parent}
+\alias{is_child_of_parent}
+\title{Helper function for children_of_parents.}
+\usage{
+is_child_of_parent(parent_id, path_to_top_parent)
+}
+\arguments{
+\item{parent_id}{[int] Location ID of parent to test}
+
+\item{path_to_top_parent}{[character] String of path to top parent from hierarchy}
+}
+\value{
+[lgl] TRUE if parent_id is in path_to_top_parent
+}
+\description{
+Given a single parent_id and a path_to_top_parent,
+returns TRUE if that parent_id is in the path.
+}
diff --git a/man/make_new_output_dir.Rd b/man/make_new_output_dir.Rd
new file mode 100644
index 0000000..c27cdad
--- /dev/null
+++ b/man/make_new_output_dir.Rd
@@ -0,0 +1,24 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/utils_io.R
+\name{make_new_output_dir}
+\alias{make_new_output_dir}
+\title{Get output directory for results to save in}
+\usage{
+make_new_output_dir(root, date)
+}
+\arguments{
+\item{root}{[chr] path to root of output results}
+
+\item{date}{[chr] character date in form of "YYYY_MM_DD" or "today". "today" will be interpreted as today's date.}
+}
+\value{
+[chr] path to new output directory
+}
+\description{
+Returns an appropriate path to save results in, creating it if necessary.
+}
+\examples{
+\dontrun{
+make_new_output_dir("my/root/folder", date = "today")
+}
+}
diff --git a/man/read_file.Rd b/man/read_file.Rd
index fe0190e..3733ebc 100644
--- a/man/read_file.Rd
+++ b/man/read_file.Rd
@@ -7,11 +7,11 @@
 read_file(path_to_file, verbose = FALSE, csv_opt = "data.table::fread", ...)
 }
 \arguments{
-\item{path_to_file}{[chr] full path with extenstion}
+\item{path_to_file}{[chr] full path with extension}
 
 \item{verbose}{[lgl] noisy or quiet function?}
 
-\item{csv_opt}{[chr] namespaced function call for csv reads (default `"data.table::fread"`)}
+\item{csv_opt}{[chr] name spaced function call for csv reads (default `"data.table::fread"`)}
 
 \item{...}{[any] additional arguments to pass to the reader function}
 }
diff --git a/man/validate_children_of_parents_inputs.Rd b/man/validate_children_of_parents_inputs.Rd
new file mode 100644
index 0000000..2259a5f
--- /dev/null
+++ b/man/validate_children_of_parents_inputs.Rd
@@ -0,0 +1,21 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/children_of_parents.R
+\name{validate_children_of_parents_inputs}
+\alias{validate_children_of_parents_inputs}
+\title{Helper function for children_of_parents.}
+\usage{
+validate_children_of_parents_inputs(parent_loc_ids, output, hierarchy)
+}
+\arguments{
+\item{parent_loc_ids}{[int] ihme location ids}
+
+\item{output}{[character] output options}
+
+\item{hierarchy}{[data.table] ihme location hierarchy}
+}
+\value{
+[none] stop on failure
+}
+\description{
+Helper function for children_of_parents.
+}
diff --git a/man/validate_parents_of_children_inputs.Rd b/man/validate_parents_of_children_inputs.Rd
new file mode 100644
index 0000000..a2fb86d
--- /dev/null
+++ b/man/validate_parents_of_children_inputs.Rd
@@ -0,0 +1,21 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/parents_of_children.R
+\name{validate_parents_of_children_inputs}
+\alias{validate_parents_of_children_inputs}
+\title{Helper function to validate inputs to function}
+\usage{
+validate_parents_of_children_inputs(child_location_id, hierarchy, parent_level)
+}
+\arguments{
+\item{child_location_id}{[int] ihme location_id}
+
+\item{hierarchy}{[data.table] ihme location hierarchy}
+
+\item{parent_level}{[int] ihme location level}
+}
+\value{
+[none] stop on failure
+}
+\description{
+Helper function to validate inputs to function
+}
diff --git a/tests/testthat/fixtures/closure_criteria_sheet.xlsx b/tests/testthat/fixtures/closure_criteria_sheet.xlsx
new file mode 100644
index 0000000..204abbd
Binary files /dev/null and b/tests/testthat/fixtures/closure_criteria_sheet.xlsx differ
diff --git a/tests/testthat/fixtures/data.csv b/tests/testthat/fixtures/data.csv
new file mode 100644
index 0000000..0be8816
--- /dev/null
+++ b/tests/testthat/fixtures/data.csv
@@ -0,0 +1,3 @@
+name,rank
+Kirk,Admiral
+Picard,Captain
diff --git a/tests/testthat/fixtures/model-inputs/2020_05_25.02/locations/ids.yaml b/tests/testthat/fixtures/model-inputs/2020_05_25.02/locations/ids.yaml
new file mode 100644
index 0000000..9d62e6d
--- /dev/null
+++ b/tests/testthat/fixtures/model-inputs/2020_05_25.02/locations/ids.yaml
@@ -0,0 +1,6 @@
+covariate:
+  location_set_id: 111
+  location_set_version_id: 680
+modeling:
+  location_set_id: 111
+  location_set_version_id: 674
diff --git a/tests/testthat/fixtures/versioned-dirs/nested/1999_09_09/1999_09_09.01/data.txt b/tests/testthat/fixtures/versioned-dirs/nested/1999_09_09/1999_09_09.01/data.txt
new file mode 100644
index 0000000..e69de29
diff --git a/tests/testthat/fixtures/versioned-dirs/nested/1999_09_09/1999_09_09.02/data.txt b/tests/testthat/fixtures/versioned-dirs/nested/1999_09_09/1999_09_09.02/data.txt
new file mode 100644
index 0000000..e69de29
diff --git a/tests/testthat/fixtures/versioned-dirs/nested/1999_09_09/1999_09_09.15blargfoobar/contents-to-populate-directory b/tests/testthat/fixtures/versioned-dirs/nested/1999_09_09/1999_09_09.15blargfoobar/contents-to-populate-directory
new file mode 100644
index 0000000..e69de29
diff --git a/tests/testthat/fixtures/versioned-dirs/nested/1999_09_09/1999_09_09.NA/QC_1999_09_09.01 b/tests/testthat/fixtures/versioned-dirs/nested/1999_09_09/1999_09_09.NA/QC_1999_09_09.01
new file mode 100644
index 0000000..e69de29
diff --git a/tests/testthat/test-utils_io.R b/tests/testthat/test-utils_io.R
index 31cd8a2..d6b8155 100644
--- a/tests/testthat/test-utils_io.R
+++ b/tests/testthat/test-utils_io.R
@@ -169,7 +169,7 @@ test_that("read_file errors correctly",
             )
           })
 
-test_that(".csv option errors and works properly with alternate functions",
+test_that("read_file .csv option errors and works properly with alternate functions",
           {
             withr::local_file(dir_full)
             dir.create(dir_full)
@@ -194,7 +194,7 @@ test_that(".csv option errors and works properly with alternate functions",
           })
 
 
-test_that("... works to pass extra args to reader function",
+test_that("read_file ... works to pass extra args to reader function",
           {
             withr::local_file(dir_full)
             dir.create(dir_full)
@@ -213,8 +213,70 @@ test_that("... works to pass extra args to reader function",
 
           })
 
+
+# cribbed from ihme.covid repo
+test_that("get_latest_output_date_index returns 0 if no dirs exist", {
+  # neither of these directories exist
+  expect_equal(0, get_latest_output_date_index("/does/not/exist", date = "2001_01_01"))
+  expect_equal(0, get_latest_output_date_index("fixtures/versioned-dirs/2000_01_01", date = "2001_01_01"))
+})
+
+test_that("get_latest_output_date_index returns correct value", {
+  expect_equal(2, get_latest_output_date_index("fixtures/versioned-dirs/nested/1999_09_09", date = "1999_09_09"))
+})
+
+test_that("get_latest_output_dir works", {
+  latest_dir <- get_latest_output_dir(root = "fixtures/versioned-dirs/nested/1999_09_09")
+
+  expect_equal(latest_dir, "fixtures/versioned-dirs/nested/1999_09_09/1999_09_09.02")
+})
+
+test_that("get_latest_output_dir errors correctly", {
+  expect_error(
+    get_latest_output_dir(root = "fixtures/DOES-NOT-EXIST"),
+    "root fixtures/DOES-NOT-EXIST does not exist"
+  )
+
+  expect_error(
+    get_latest_output_dir(root = "fixtures/versioned-dirs"),
+    "No YYYY_MM_DD.VV directories in fixtures/versioned-dirs"
+  )
+})
+
+
+test_that("get_new_output_dir functionality works", {
+
+  # create random root directory with self-teardown (`teardown()` is deprecated)
+  withr::local_file(dir_full)
+  dir.create(dir_full)
+
+  # expect bootstrap to work
+  expect_equal(file.path(dir_full, "1999_09_09.01"), get_new_output_dir(root = dir_full, date = "1999_09_09"))
+  expect_false(dir.exists(file.path(dir_full, "1999_09_09.01")))
+})
+
+
+test_that("make_new_output_dir functionality works", {
+
+  # create random root directory with self-teardown (`teardown()` is deprecated)
+  withr::local_file(dir_full)
+  dir.create(dir_full)
+
+  # expect bootstrap to work
+  expect_equal(file.path(dir_full, "1999_09_09.01"), make_new_output_dir(root = dir_full, date = "1999_09_09"))
+  expect_true(dir.exists(file.path(dir_full, "1999_09_09.01")))
+
+  # incrementing automatically happens
+  expect_equal(file.path(dir_full, "1999_09_09.02"), make_new_output_dir(root = dir_full, date = "1999_09_09"))
+
+  # handle convenience "today" value
+  today.v1 <- format(Sys.Date(), "%Y_%m_%d.01")
+  expect_equal(file.path(dir_full, today.v1), make_new_output_dir(root = dir_full, date = "today"))
+})
+
+
 # Last test
-test_that("tempdir (dir_parent) exists and dir_full does not",
+test_that("test cleanup works - tempdir (dir_parent) exists and dir_full does not",
           {
             expect_true(dir.exists(dir_parent))
             expect_false(dir.exists(dir_full))