feat: Neovim-specific rules

[kiyoon]

Neovim has one of the biggest Lua 5.1 user bases, and I believe that Neovim-specific lint rules that help plugin development would be a good idea.

Other linters like ruff or biome has a framework/library-specific lint rules like Numpy, FastAPI, React, etc.

Example 1

Neovim APIs change over version. For example, according to https://neovim.io/doc/user/news-0.10.html,

vim.tbl_contains() now works for general tables and allows specifying a predicate function that is checked for each value. (Use vim.list_contains() for checking list-like tables (integer keys without gaps) for literal values.)

Example 2

I also remember that when I tried to use vim.fn.system(), the lua-language-server told me I should use vim.system()

https://github.com/neovim/neovim/blob/a99c469e547fc59472d6d105c0fae323958297a1/runtime/lua/vim/_meta/vimfn.lua#L4856

--- Note: Prefer |vim.system()| in Lua.

So I used that function only to realise that it's new from nvim-0.10 and I broke compatibility for all previous versions of Neovim.

Example 3

Treesitter functions change a lot, for example, https://github.com/nvim-treesitter/nvim-treesitter-context/blob/6daca3ad780f045550b820f262002f35175a6c04/lua/treesitter-context/context.lua#L96-L103

  -- max_start_depth depth is only supported in nvim 0.10. It is ignored on
  -- versions 0.9 or less. It is only needed to improve performance
  for _, match in query:iter_matches(node, bufnr, 0, -1, { max_start_depth = 0 }) do
    local r = false

    for id, nodes in pairs(match) do
      --- In Nvim 0.9 node is a TSNode, in Nvim 0.10+ it is a list of TSNode
      --- @type TSNode

In these few lines, you can read that there are two differences over the nvim version.

Example 4

In Neovim 0.11, the vim.str_byteindex() API has been changed: neovim/neovim#30804

So you can suggest to migrate if the target version is over nvim 0.11.

---

If you don't use Neovim, you might think there are too many things to address that you don't really know. However, I feel like such lints are easy to implement (write target nvim version and restrict some function calls / suggest other functions etc.) and once some lints are available, more nvim users will use this linter and they will suggest more lints and even help you implement them.