Eval not working (code action disappears) when a certain function exists in buffer

[leana8959]

Neovim version (nvim -v)

v0.9.1

Operating system/version

macOS 13.4.1

Output of haskell-language-server-wrapper --version

2.0.0.1 (GHC: 9.4.4)

How to reproduce the issue

I made a repr project repo here. Please go to Q1to10.hs

Here's a snippet of the problematic code:

-- Recursive method
-- We can only match on the left side of the list
-- which means we can only construct the list from the right (reversed).
-- This is less efficient because Haskell's lists are linked lists.
myReverse :: [a] -> [a]
myReverse [] = []
myReverse (x : xs) = myReverse xs ++ [x]

-- 8
-- >>> head [1,2,3]
compress :: (Eq a) => [a] -> [a]
compress [] = []
compress (x : xs) = x : compress (dropWhile (== x) xs)

If I keep the paragraph of code above --8, the codeaction button would disappear and the command to evaluate would not run.

I also tried to add another eval line above "myReverse". It the line above "myReverse" would work and the one below wouldn't.

Expected behaviour

Evaluate lines starting with -- >>>.

Actual behaviour

Code action button disappears, command / keybind doesn't actuate the evaluation.

Log files

https://gist.github.com/leana8959/5e417d4c36e84f8b14f1a1b33bd5d9e1

The minimal config used to reproduce this issue.

-- Minimal nvim config with packer
-- Assumes a directory in $NVIM_DATA_MINIMAL
-- Start with $NVIM_DATA_MINIMAL=$(mktemp -d) nvim -u minimal.lua
-- Then exit out of neovim and start again.

-- Ignore default config
local fn = vim.fn
local config_path = fn.stdpath('config')
vim.opt.runtimepath:remove(config_path)

-- Ignore default plugins
local data_path = fn.stdpath('data')
local pack_path = data_path .. '/site'
vim.opt.packpath:remove(pack_path)

--append temporary config and pack dir
data_path = os.getenv('NVIM_DATA_MINIMAL')
if not data_path then
    error('$NVIM_DATA_MINIMAL environment variable not set!')
end
vim.opt.runtimepath:append('.')
vim.opt.runtimepath:append(data_path)
vim.opt.runtimepath:append(data_path .. '/site/pack/packer/start/plenary.nvim')
vim.opt.packpath:append(data_path .. '/site')

-- bootstrap packer
local packer_install_path = data_path .. '/site/pack/packer/start/packer.nvim'
local install_plugins = false

if vim.fn.empty(vim.fn.glob(packer_install_path)) > 0 then
    vim.cmd('!git clone [email protected]:wbthomason/packer.nvim ' .. packer_install_path)
    vim.cmd('packadd packer.nvim')
    install_plugins = true
else
    vim.cmd('packadd packer.nvim')
end

local packer = require('packer')

packer.init {
    package_root = data_path .. '/site/pack',
    compile_path = data_path .. '/plugin/packer_compiled.lua',
}

vim.cmd('runtime! plugin/plenary.vim')

packer.startup(function(use)
    use('wbthomason/packer.nvim')
    use {
        'mrcjkb/haskell-tools.nvim',
        requires = {
            'nvim-lua/plenary.nvim',
        },
        branch = '1.x.x',
    }
end)


-- haskell-tools config
local on_attach = function(_, bufnr)
    vim.api.nvim_buf_set_option(bufnr, 'omnifunc', 'v:lua.vim.lsp.omnifunc')

    vim.keymap.set('n', '<space>hs', require("haskell-tools").hoogle.hoogle_signature,
        { desc = "Hoogle signature", buffer = bufnr })
    vim.keymap.set('n', '<space>he', require("haskell-tools").lsp.buf_eval_all, { desc = "Evaluate all", buffer = bufnr })
end

local setup_ht = function()
    require("haskell-tools").start_or_attach {
        tools = {
            hover = {
                stylize_markdown = true,
            }
        },
        hls = {
            on_attach = on_attach,
            default_settings = {
                haskell = {
                    formattingProvider = "ormolu"
                }
            }
        }
    }
end
vim.api.nvim_create_autocmd("FileType", {
    pattern = { "haskell", "lhaskell", "cabal" },
    callback = setup_ht,
})

[mrcjkb]

Thanks for reporting this.

This is a bug in haskell-language-server. See:

• Evaluate/Refresh links missing following multiple-equation definitions haskell/haskell-language-server#3129
• Eval plugin appears to stop working after a function def that has more than one pattern match haskell/haskell-language-server#3312