Analog of r-here or py-here for Julia

Question

BACKGROUND
One of the very useful tools for reproducible work in R is the "here" library.

• https://malco.io/2018/11/05/why-should-i-use-the-here-package-when-i-m-already-using-projects/
• http://jenrichmond.rbind.io/post/how-to-use-the-here-package/
• https://here.r-lib.org/
• https://here.r-lib.org/articles/rmarkdown.html

I was hooked by the part in the first link where they said this:

The "here" library is encoded in Anaconda as "r-here"

I'm not sure which came first, but Python has a "here" library as well.

• https://pypi.org/project/pyhere/
• https://github.com/wildland-creative/pyhere

"Here" makes relative paths a trivial matter, which is really useful for reproducible data-science and analysis work.

QUESTION
What is the Julia equivalent for clean handling of relative paths for files? Is there a clean way to integrate that with project packaging, like RStudio does?

Answer 1

Based on the description, it sounds like DrWatson.jl does what you're looking for. From the website:

[DrWatson] is a Julia package created to help people increase the consistency of their scientific projects, navigate them and share them faster and easier, manage scripts, existing simulations as well as project source code. DrWatson helps establishing reproducibility, and in general it makes managing a scientific project a simple job.

Like the description implies, it's more ambitious than here seems to be, having functionality to also manage data, simulation runs, etc. But they're optional, and you can use only the directory handling part if you need.

The Navigating a Project describes the projectdir function which works similar to here. projectdir("foo", "bar") resolves to foo/bar under the current project's root directory, just like with here.

There's also datadir(), srcdir(), and others to directly handle common subdirectories under a project for eg. datadir("foo", "test.jld2") resolves to data/foo/test.jld2 under the project's root directory.

Answer 2

It doesn't exist, as far as I'm aware (Here.jl doesn't return any Google hits), but it seems like it would a simple enough for someone to implement. Maybe you!

Answer 3

Edit

I've created a package with a function that does this now: https://github.com/jolars/ProjectRoot.jl. You just need to call

@projectroot("plots", "figure.pdf")

to construct a file path relative to the project root.

The previous answer to this question did not actually work properly either since the @__DIR__ macro is resolved at compile time and will return the directory of the file in which it is defined, which is not what you want.

Previous (and incorrect) answer

The answer below does not work properly since it retrieves @___DIR__ from where the function is defined, and not from where the function is called.

I came up with this solution, which works well in my case, which is to either run code interactively through an REPL (with the project root as working directory) or via the command line calling the script.

using FilePathsBase

# Return the root of the project
function project_root(current_dir = @__DIR__)
  while current_dir != "/"
    if isdir(joinpath(current_dir, ".git")) ||
       isfile(joinpath(current_dir, "Project.toml"))
      return current_dir
    end
    current_dir = dirname(current_dir)
  end
  error("Project root not found")
end

# Construct paths relative to the project root
here(args...) = joinpath(project_root(), args...)

Use like this:

here("data", "my_data_file.json")

I'm sure this can be improved upon to handle more settings other than git and julia projects.