Possible error when deprecating binaries path for assets

[garazdawi]

Before f4a46cb it was possible to have hidden files in the asset folder without them being included in the build. For instance we had a .gitignore file in the assets folder.

With f4a46cb it is no longer possible and we get this error:

** (RuntimeError) asset with extension "" is not supported by EPUB format
    (ex_doc 0.34.0) lib/ex_doc/formatter/epub/templates.ex:138: ExDoc.Formatter.EPUB.Templates.media_type/1
    (ex_doc 0.34.0) lib/ex_doc/formatter/epub/templates/content_template.eex:27: anonymous fn/1 in ExDoc.Formatter.EPUB.Templates.content_template/5
    (elixir 1.17.0-dev) lib/enum.ex:1700: Enum."-map/2-lists^map/1-1-"/2
    (elixir 1.17.0-dev) lib/enum.ex:1700: Enum."-map/2-lists^map/1-1-"/2
    (ex_doc 0.34.0) lib/ex_doc/formatter/epub/templates/content_template.eex:26: ExDoc.Formatter.EPUB.Templates.content_template/5
    (ex_doc 0.34.0) lib/ex_doc/formatter/epub.ex:85: ExDoc.Formatter.EPUB.generate_content/5
    (ex_doc 0.34.0) lib/ex_doc/formatter/epub.ex:41: ExDoc.Formatter.EPUB.run/3
    (ex_doc 0.34.0) lib/ex_doc/cli.ex:69: anonymous fn/6 in ExDoc.CLI.generate/3

It is not a big problem for us to remove the .gitignore, just opening this issue to see if the original behaviour was intentional or not.

[josevalim]

We should fix this I think. I wonder if we should do it by explicitly discarding .gitignore or by discarding everything starting with .. Thoughts?

[garazdawi]

Since . indicates hidden on Unix I think that we should discard all those, which I think is what the old implementation did.

[josevalim]

I decided to keep all assets because we do a recursive traversal and skipping dot files in there would require adding a feature to Elixir first. Which basically means the empty .gitignore file will be part of the assets. If that's an issue, let me know, I will be glad to revisit it. :)

[garazdawi]

Sounds good to me. I did an attempt att solving this and ended up with this hack:

is_binary(dir_or_files) and File.dir?(dir_or_files) ->
  dir_or_files
  |> File.cp_r!(target_dir)
  |> Enum.filter(fn path ->
    ## Remove any file that starts with a .
    if path |> Path.basename() |> String.first() != "." do
      File.rm!(path)
      false
    else
      true
    end
  end)
  |> Enum.map(&Path.relative_to(&1, output))