RFC: Add remove_atexit keyword argument to mktempdir(parent)

base/file.jl

@@ -518,14 +518,18 @@ is an open file object for this path.
 mktemp(parent)
 
 """
-    mktempdir(parent=tempdir(); prefix=$(repr(temp_prefix)))
+    mktempdir(parent=tempdir(); prefix=$(repr(temp_prefix)), remove_atexit=false)
 
 Create a temporary directory in the `parent` directory with a name
 constructed from the given prefix and a random suffix, and return its path.
 Additionally, any trailing `X` characters may be replaced with random characters.
 If `parent` does not exist, throw an error.
+
+!!! compat "Julia 1.3"
+    The `remove_atexit` keyword argument requires at least Julia 1.3.
+    If `remove_atexit` is true, then the temporary directory will be removed when Julia exits.
 """
-function mktempdir(parent=tempdir(); prefix=temp_prefix)
+function mktempdir(parent=tempdir(); prefix=temp_prefix, remove_atexit=false)
     if isempty(parent) || occursin(path_separator_re, parent[end:end])
         # append a path_separator only if parent didn't already have one
         tpath = "$(parent)$(prefix)XXXXXX"
@@ -544,6 +548,9 @@ function mktempdir(parent=tempdir(); prefix=temp_prefix)
         end
         path = unsafe_string(ccall(:jl_uv_fs_t_path, Cstring, (Ptr{Cvoid},), req))
         ccall(:uv_fs_req_cleanup, Cvoid, (Ptr{Cvoid},), req)
+        if remove_atexit
+            atexit(() -> rm(path; force=true, recursive=true))
+        end
         return path
     finally
         Libc.free(req)

test/file.jl

@@ -6,6 +6,18 @@
 starttime = time()
 pwd_ = pwd()
 dir = mktempdir()
+code = """
+child_dir = mktempdir(; remove_atexit=true)
+ispath(child_dir) || error("`child_dir` is not a path")
+isdir(child_dir) || error("`child_dir` is not a directory")
+println(child_dir)
+"""
+cmd = ```
+$(Base.julia_cmd()) --eval $code
+```
+child_dir = chomp(read(cmd, String))
+@test !isdir(child_dir)
+@test !ispath(child_dir)
 file = joinpath(dir, "afile.txt")
 # like touch, but lets the operating system update the timestamp
 # for greater precision on some platforms (windows)