Getting JuliaFormatter to work with helix editor

[vishalpaudel]

When doing

$ hx --health julia  # I get:
Configured language servers:
  ✓ julia: /home/vishal/.juliaup/bin/julia
Configured debug adapter: None
Configured formatter: None
Highlight queries: ✓
Textobject queries: ✓
Indent queries: ✓

So, I would like to setup a formatter for julia. In this case I am using JuliaFormatter.

When doing

$ julia -e 'using JuliaFormatter; format(ARGS[1]);' src/main.jl

The file is successfully formatted automatically.

But editing helix-config/languages.toml, to include:

[[language]]
name = "julia"
formatter = { command = "julia", timeout = 60, args = [ "-e", "using JuliaFormatter; format(ARGS[1]);", ] }

And manually running helix::format inside helix on the same file, I get helix-log julia error:

2024-08-17T11:32:06.020 helix_view::document [ERROR] Formatter error: ERROR: BoundsError: attempt to access 0-element Vector{String} at index [1]
Stacktrace:
 [1] getindex(A::Vector{String}, i1::Int64)
   @ Base ./essentials.jl:13
 [2] top-level scope
   @ none:1

Which hints that the formatter does not recieve the path of the file as an argument? How should I go about adding the said JuliaFormatter to helix? What is expected off of the formatter command? What is passed to the formatter command?

[vishalpaudel]

possibly related: #3596

[vishalpaudel]

Maybe STDIN needs to be read.

[the-mikedavis]

External formatters are passed the file contents as stdin and are expected to print the formatter doc as stdout

[sschuldenzucker]

FWIW I found the following to work fine:

formatter = { command = "julia", timeout = 60, args = [ "--startup-file=no", "--history-file=no", "--project", "--quiet", "-e", "using JuliaFormatter; print(format_text(read(stdin, String)));", ] }

(passing --project is a matter of taste but I do it so I can control the version of JuliaFormatter to use for my local project)