Trying to add the moonc Moonscript Linter

[BioBox]

Hello. I'm trying to make a small mpv plugin, and much to my delight moonscript (which compiles to lua) comes with a linter. It doesn't fall into the supported list, but I thought "hey, I know vimscript well enough, I'll just add it."

Well, I wrote the code for it based off of luac. The linter and handler tests work but I cannot for the life of me get the errors/warnings to show in an actual real-life example. My fork is linked here.

What am I doing wrong? I've spent hours reading the docs and looking through the source code and I still can't get it to work. It's getting to be frustrating. Can anyone help me out with this please? I know for sure that:

1. The moonc linter is loaded.
2. The vader tests that I wrote pass.

And yet nothing gives.

[hsanson]

What does ALEInfo tell you? It may provide hints on what is going on.

[BioBox]

 Current Filetype: moon
Available Linters: ['moonc']
  Enabled Linters: ['moonc']
  Ignored Linters: []
 Suggested Fixers: 
  'remove_trailing_lines' - Remove all blank lines at the end of a file.
  'trim_whitespace' - Remove all trailing whitespace characters at the end of every line.
 Linter Variables:

let g:ale_moon_moonc_executable = 'moonc'
 Global Variables:

let g:ale_cache_executable_check_failures = v:null
let g:ale_change_sign_column_color = v:null
let g:ale_command_wrapper = v:null
let g:ale_completion_delay = v:null
let g:ale_completion_enabled = 0
let g:ale_completion_max_suggestions = v:null
let g:ale_disable_lsp = 1
let g:ale_echo_cursor = 1
let g:ale_echo_msg_error_str = 'Error'
let g:ale_echo_msg_format = v:null
let g:ale_echo_msg_info_str = 'Info'
let g:ale_echo_msg_warning_str = 'Warning'
let g:ale_enabled = 1
let g:ale_fix_on_save = 0
let g:ale_fixers = {}
let g:ale_history_enabled = 1
let g:ale_history_log_output = 1
let g:ale_keep_list_window_open = v:null
let g:ale_lint_delay = 200
let g:ale_lint_on_enter = 1
let g:ale_lint_on_filetype_changed = 1
let g:ale_lint_on_insert_leave = 1
let g:ale_lint_on_save = 1
let g:ale_lint_on_text_changed = 'normal'
let g:ale_linter_aliases = {}
let g:ale_linters = {'moon': ['moonc']}
let g:ale_linters_explicit = 0
let g:ale_linters_ignore = {}
let g:ale_list_vertical = v:null
let g:ale_list_window_size = v:null
let g:ale_loclist_msg_format = v:null
let g:ale_max_buffer_history_size = 20
let g:ale_max_signs = v:null
let g:ale_maximum_file_size = v:null
let g:ale_open_list = v:null
let g:ale_pattern_options = v:null
let g:ale_pattern_options_enabled = v:null
let g:ale_root = {}
let g:ale_set_balloons = 0
let g:ale_set_highlights = 1
let g:ale_set_loclist = 1
let g:ale_set_quickfix = 0
let g:ale_set_signs = 1
let g:ale_sign_column_always = v:null
let g:ale_sign_error = v:null
let g:ale_sign_info = v:null
let g:ale_sign_offset = v:null
let g:ale_sign_style_error = v:null
let g:ale_sign_style_warning = v:null
let g:ale_sign_warning = v:null
let g:ale_sign_highlight_linenrs = v:null
let g:ale_statusline_format = v:null
let g:ale_type_map = v:null
let g:ale_use_neovim_diagnostics_api = 0
let g:ale_use_global_executables = v:null
let g:ale_virtualtext_cursor = 'all'
let g:ale_warn_about_trailing_blank_lines = 1
let g:ale_warn_about_trailing_whitespace = 1
  Command History:

[hsanson]

I tested your branch and seems to work properly... ALE tries to load the linter:

let g:ale_sign_offset = 1000000
let g:ale_sign_style_error = ''
let g:ale_sign_style_warning = ''
let g:ale_sign_warning = ''
let g:ale_sign_highlight_linenrs = 0
let g:ale_statusline_format = v:null
let g:ale_type_map = {}
let g:ale_use_neovim_diagnostics_api = 0
let g:ale_use_global_executables = v:null
let g:ale_virtualtext_cursor = 1
let g:ale_warn_about_trailing_blank_lines = 1
let g:ale_warn_about_trailing_whitespace = 1
  Command History:
(executable check - failure) moonc

In my case it stops because I do not have moonc installed but if found it should then call the linter and parse the output. Whenever ALE stops at Command History without doing anything else is usually a configuration issue. Try setting a minimal vim config file that incluses only ALE and try then opening a moon file. For example I use this init file whenever I want to test stuff:

call plug#begin('~/.config/nvim/bundle')
Plug '~/Projects/vim/ale'
call plug#end()
filetype plugin indent on

let g:ale_linters = {}
let g:ale_fixers = {}

let g:ale_linters.moon = ['moonc']

Note it uses "vim-plug" to load the plugins. You can use any other method you prefer to load plugins.

Also I would like to mention that on my vim files with moon extension are recognized as "moonscript" filetype so I had to force the filetype to "moon" for your linter to trigger.