Add some python-lsp-server configuration customization

[baco]

Is your feature request related to a problem? Please describe.

I'd like to be able to parametrize (it could be via ensure_installed or automatic_installation, or something) the installation of the server.

Describe the solution you'd like

to be able to achieve 2 behaviors:

1. Being able to install some (not all) of the plugins the server has. Say I want to be able to specify python-lsp-server[pylint,flake8] instead of the default python-lsp-server[all], to avoid installing plugins I don't use, or that could clash with others in system.
2. Being able to specify a way to install automatically, alongside the server, some third-party plugins. For instance, I would like to be able to set on my Neovim init.lua file, as well as I have the automatic_installation setting for the automatic installation of the server, a way to automatically install certain third-party plugins. For example I want to be able to say python-lsp-server[pylsp-mypy] in such setting, without having to manually run :PylspInstall pylsp-mypy once the server was installed.

Describe potential alternatives you've considered

I can achieve installation like this myself if I control the virtualenvironments in which I install the server.

Additional context

No response

[williamboman]

Hello! Ah hm I wasn't aware the [all] specifier would install all plugins, I assumed it was for something else. Am I correct in assuming that the :PylspInstall command is pretty redundant then, as most of those sub-packages are already installed?

This relates to https://github.com/williamboman/mason.nvim/issues/392 which I'm working on atm

[baco]

I don't think :PylspInstall is redundant, because without it, at the moment, python-lsp-server[all] won't install, for instance, pylsp-mypy as it is a third-party plugin.

python-lsp-server[all] (or a sub-set [pylint,flake8]) installs all official plugins, but not the third-party ones.

The behavior I want is to, even for third-party plugins, have a setting in mason-lspconfig that gets them installed automatically as it is with most servers.

I suggested copying the same syntax pip uses to install sub-packages, but the detection of which are official plugins and which not, in that case, remains to the core of mason to be able to form the line for the installer

[dsully]

A work around for not having this functionality:

{
        "williamboman/mason.nvim",
        cmd = { "Mason", "MasonInstall", "MasonUninstall" },
        config = function()
            require("mason").setup()

            require("mason-registry"):on("package:install:success", require("...").mason_post_install)
        end
}

M.mason_post_install = function(pkg)
    if pkg.name ~= "python-lsp-server" then
        return
    end

    local venv = vim.fn.stdpath("data") .. "/mason/packages/python-lsp-server/venv"
    local job = require("plenary.job")

    job:new({
        command = venv .. "/bin/pip",
        args = {
            "install",
            "-U",
            "--disable-pip-version-check",
            "pylsp-mypy",
            "python-lsp-ruff",
        },
        cwd = venv,
        env = { VIRTUAL_ENV = venv },
        on_exit = function()
            vim.notify("Finished installing pylsp modules.")
        end,
        on_start = function()
            vim.notify("Installing pylsp modules...")
        end,
    }):start()
end

[octvs]

In case someone has a hard time making @dsully's solution work. I had two issues with it:

• plenary.nvim not being loaded at the callback moment: In my case it was lazy loaded so adding it to dependencies here solves it:

  return {
  "williamboman/mason.nvim",
  cmd = { "Mason", "MasonInstall", "MasonUninstall" },
  dependencies = { "nvim-lua/plenary.nvim" }, -- needed for mason_post_install
  config = function()
  ...

• not having nvim-notify installed: I don't have this plugin and the default vim.notify call would throw and error during execution. You can comment those out, or change to print.

[PBHDK]

Thank you, @dsully and @octvs - exactly what I needed! Due to some issues with my machine, the PylspInstall command wasn't working. This solved the problem altogether and automates the installation for future use. Brilliant!