dotfiles/nvim/lua/cmp_config.lua

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

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)
      require('luasnip').lsp_expand(args.body) -- For `luasnip` users.
    end,
  },
  mapping = {
    ['<C-k>'] = cmp.mapping.select_prev_item(),
    ['<C-p>'] = cmp.mapping.select_prev_item(),
    ['<C-j>'] = cmp.mapping.select_next_item(),
    ['<C-n>'] = cmp.mapping.select_next_item(),
    ['<C-d>'] = 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, -- Specify `cmp.config.disable` if you want to remove the default `<C-y>` mapping.
    ['<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 = 'path' },
    { name = 'nvim_lsp', keyword_length = 3 },
    { name = 'nvim_lsp_signature_help' },
    { name = 'nvim_lua', keyword_length = 2 },
    { name = 'nvim_lua', keyword_length = 2 },
    { name = 'buffer' },
    { name = 'luasnip' }, -- For luasnip users.
  }),
  window = {
    completion = cmp.config.window.bordered(),
    documentation = cmp.config.window.bordered(),
  },
  formatting = {
    fields = { 'menu', 'abbr', 'kind' },
    format = function(entry, item)
      local menu_icon = {
        nvim_lsp = 'λ',
        buffer = 'Ω'
      }
      item.menu = menu_icon[entry.source.name]
      return item
    end
  }
})

cmp.setup.cmdline('/', {
  sources = {
    { name = 'buffer' }
  }
})

cmp.setup.cmdline(':', {
  sources = cmp.config.sources({
    { name = 'path' }
  }, { { name = 'cmdline' } })
})