nixos-config/home/editors/neovim/completion.lua

local cmp = require("cmp")
local luasnip = require("luasnip")

-- vim.opt.completeopt="menuone,noinsert" -- TODO
vim.opt.completeopt="menu,menuone,noselect"
vim.opt.shortmess:append("c")

local has_words_before = function()
  local line, col = unpack(vim.api.nvim_win_get_cursor(0))
  return col ~= 0 and vim.api.nvim_buf_get_lines(0, line - 1, line, true)[1]:sub(col, col):match("%s") == nil
end

cmp.setup({
  snippet = {
    expand = function(args)
      luasnip.lsp_expand(args.body)
    end,
  },
  mapping = {
    ["<C-b>"] = cmp.mapping(cmp.mapping.scroll_docs(-4), { "i", "c" }),
    ["<C-f>"] = cmp.mapping(cmp.mapping.scroll_docs(4), { "i", "c" }),
    ["<C-Space>"] = cmp.mapping(cmp.mapping.complete(), { "i", "c" }),
    ["<C-y>"] = cmp.config.disable,
    ["<C-e>"] = cmp.mapping({
      i = cmp.mapping.abort(),
      c = cmp.mapping.close(),
    }),
    ["<CR>"] = cmp.mapping.confirm({ select = true }),
    ["<Tab>"] = cmp.mapping(function(fallback)
      if cmp.visible() then
        cmp.select_next_item()
      elseif luasnip.expand_or_jumpable() then
        luasnip.expand_or_jump()
      elseif has_words_before() then
        cmp.complete()
      else
        fallback()
      end
    end, { "i", "s" }),
    ["<S-Tab>"] = cmp.mapping(function(fallback)
      if cmp.visible() then
        cmp.select_prev_item()
      elseif luasnip.jumpable(-1) then
        luasnip.jump(-1)
      else
        fallback()
      end
    end, { "i", "s" }),
  },
  sources = cmp.config.sources({
    { name = "nvim_lsp" },
    { name = "luasnip" },
    { name = "path" },
  }, {
    { name = "buffer" },
  })
})

local cmp_autopairs = require("nvim-autopairs.completion.cmp")
cmp.event:on("confirm_done", cmp_autopairs.on_confirm_done({  map_char = { tex = "" } }))