ZIP file structures
In usethis: Automate Package and Project Setup

knitr::opts_chunk$set(comment = "#>", collapse = TRUE)

devtools::load_all("~/rrr/usethis")
library(fs)

Different styles of ZIP file

Examples based on foo folder found here.

tree foo

Not Loose Parts, a.k.a. GitHub style

This is the structure of ZIP files yielded by GitHub via links of the forms https://github.com/r-lib/usethis/archive/master.zip and http://github.com/r-lib/usethis/zipball/master/.

```{bash, eval = FALSE} zip -r foo-not-loose.zip foo/

Notice that everything is packaged below one top-level directory.

```r
foo_not_loose_files <- unzip("foo-not-loose.zip", list = TRUE)
with(
  foo_not_loose_files,
  data.frame(Name = Name, dirname = path_dir(Name), basename = path_file(Name))
)

Loose Parts, the Regular Way

This is the structure of many ZIP files I've seen, just in general.

```{bash, eval = FALSE} cd foo zip ../foo-loose-regular.zip * cd ..

All the files are packaged in the ZIP archive as "loose parts", i.e. there is no explicit top-level directory.

```r
foo_loose_regular_files <- unzip("foo-loose-regular.zip", list = TRUE)
with(
  foo_loose_regular_files,
  data.frame(Name = Name, dirname = path_dir(Name), basename = path_file(Name))
)

Loose Parts, the DropBox Way

This is the structure of ZIP files yielded by DropBox via links of this form https://www.dropbox.com/sh/12345abcde/6789wxyz?dl=1. I can't figure out how to even do this with zip locally, so I had to create an example on DropBox and download it. Jim Hester reports it is possible with archive::archive_write_files().

https://www.dropbox.com/sh/5qfvssimxf2ja58/AABz3zrpf-iPYgvQCgyjCVdKa?dl=1

It's basically like the "loose parts" above, except it includes a spurious top-level directory "/".

# curl::curl_download(
#   "https://www.dropbox.com/sh/5qfvssimxf2ja58/AABz3zrpf-iPYgvQCgyjCVdKa?dl=1",
#    destfile = "foo-loose-dropbox.zip"
# )
foo_loose_dropbox_files <- unzip("foo-loose-dropbox.zip", list = TRUE)
with(
  foo_loose_dropbox_files,
  data.frame(Name = Name, dirname = path_dir(Name), basename = path_file(Name))
)

Also note that, when unzipping with unzip in the shell, you get this result:

Archive:  foo-loose-dropbox.zip
warning:  stripped absolute path spec from /
mapname:  conversion of  failed
  inflating: file.txt

So this is a pretty odd ZIP packing strategy. But we need to plan for it.

Subdirs only at top-level

Let's make sure we detect loose parts (or not) when the top-level has only directories, not files.

Example based on the yo directory here:

tree yo

```{bash, eval = FALSE} zip -r yo-not-loose.zip yo/

```r
(yo_not_loose_files <- unzip("yo-not-loose.zip", list = TRUE))
top_directory(yo_not_loose_files$Name)

```{bash, eval = FALSE} cd yo zip -r ../yo-loose-regular.zip * cd ..

```r
(yo_loose_regular_files <- unzip("yo-loose-regular.zip", list = TRUE))
top_directory(yo_loose_regular_files$Name)

# curl::curl_download(
#   "https://www.dropbox.com/sh/afydxe6pkpz8v6m/AADHbMZAaW3IQ8zppH9mjNsga?dl=1",
#    destfile = "yo-loose-dropbox.zip"
# )
(yo_loose_dropbox_files <- unzip("yo-loose-dropbox.zip", list = TRUE))
top_directory(yo_loose_dropbox_files$Name)