init.lua for neovim 0.8+, with packer and treesitter and lsp (autocomplete)

base.mapping.vim

let g:python3_host_prog = '/usr/bin/python3'
let g:python_host_prog = '/usr/bin/python3'
let g:node_host_prog = '/Users/amitava.ghosh/.nvm/versions/node/v17.1.0/bin/node'

" Required:

filetype plugin indent on


"*****************************************************************************
"" Basic Setup
"*****************************************************************************"
"" Encoding
set updatetime=200
set encoding=utf-8
set fileencoding=utf-8
set fileencodings=utf-8
set ttyfast
set nrformats+=alpha

"spell check
set nospell
let g:enable_spelunker_vim = 1
let g:spelunker_target_min_char_len = 4
let g:spelunker_check_type = 2

"" Fix backspace indent
set backspace=indent,eol,start
set nobackup nowritebackup

"" Tabs. May be overridden by autocmd rules
set tabstop=4
set softtabstop=0
set shiftwidth=4
set expandtab

"" Enable hidden buffers
set hidden

"" Searching
set hlsearch
set incsearch
set ignorecase
set smartcase

set fileformats=unix,dos,mac

if exists('$SHELL')
    set shell=$SHELL
else
    set shell=/bin/sh
endif

" session management
let g:session_directory = "~/./session"
let g:session_autoload = "no"
let g:session_autosave = "no"
let g:session_command_aliases = 1

syntax on
set ruler
set relativenumber
set noswapfile
set foldmethod=syntax


set mouse=a
set foldmethod=indent
set foldlevel=5
set nofoldenable

set guioptions=egmrti

" Search mappings: These will make it so that going to the next one in a
" search will center on the line it's found in.
nnoremap n nzzzv
nnoremap N Nzzzv

"*****************************************************************************
"" Abbreviations
"*****************************************************************************
"" no one is really happy until you have this shortcuts
cnoreabbrev W! w!
cnoreabbrev Q! q!
cnoreabbrev Qall! qall!
cnoreabbrev Wq wq
cnoreabbrev Wa wa
cnoreabbrev Qa qa
cnoreabbrev Wqa wqa
cnoreabbrev wQ wq
cnoreabbrev WQ wq
cnoreabbrev W w
cnoreabbrev Q q
cnoreabbrev Qall qall

" terminal emulation
nnoremap <silent> <leader>sh :terminal<CR>


"*****************************************************************************
"" Commands
"*****************************************************************************
" remove trailing whitespaces
command! FixWhitespace :%s/\s\+$//e

"*****************************************************************************
"" Functions
"*****************************************************************************
if !exists('*s:setupWrapping')
  function s:setupWrapping()
    set wrap
    set wm=2
    set textwidth=79
  endfunction
endif

"*****************************************************************************
"" Autocmd Rules
"*****************************************************************************
"" The PC is fast enough, do syntax highlight syncing from start unless 200 lines
augroup vimrc-sync-fromstart
  autocmd!
  autocmd BufEnter * :syntax sync maxlines=200
augroup END

"" Remember cursor position
augroup vimrc-remember-cursor-position
  autocmd!
  autocmd BufReadPost * if line("'\"") > 1 && line("'\"") <= line("$") | exe "normal! g`\"" | endif
augroup END

"" txt
augroup vimrc-wrapping
  autocmd!
  autocmd BufRead,BufNewFile *.txt call s:setupWrapping()
augroup END

"" make/cmake
augroup vimrc-make-cmake
  autocmd!
  autocmd FileType make setlocal noexpandtab
  autocmd BufNewFile,BufRead CMakeLists.txt setlocal filetype=cmake
augroup END

set autoread

"*****************************************************************************
"" Mappings
"*****************************************************************************

"" Split
noremap <Leader>h :<C-u>split<CR>
noremap <Leader>v :<C-u>vsplit<CR>

"" Tabs
nnoremap <Tab> gt
nnoremap <S-Tab> gT
nnoremap <silent> <S-t> :tabnew<CR>
nnoremap <leader><leader> gt

"" Set working directory
nnoremap <leader>. :lcd %:p:h<CR>

"" Opens an edit command with the path of the currently edited file filled in
" noremap <Leader>e :e <C-R>=expand("%:p:h") . "/" <CR>

"" Opens a tab edit command with the path of the currently edited file filled
noremap <Leader>te :tabe <C-R>=expand("%:p:h") . "/" <CR>

"" fzf.vim
set wildmode=list:longest,list:full
set wildignore+=*.o,*.obj,.git,*.rbc,*.pyc,__pycache__

"" Copy/Paste/Cut
if has('unnamedplus')
  set clipboard=unnamed,unnamedplus
endif

noremap YY "+y<CR>
noremap <leader>p "+gP<CR>
noremap XX "+x<CR>

if has('macunix')
  " pbcopy for OSX copy/paste
  vmap <C-x> :!pbcopy<CR>
  vmap <C-c> :w !pbcopy<CR><CR>
endif

"" Buffer nav
noremap <leader>z :bp<CR>
noremap <leader>q :bp<CR>
noremap <leader>x :bn<CR>
noremap <leader>w :bn<CR>

"" Close buffer
noremap <leader>c :bd<CR>

"" Clean search (highlight)
nnoremap <silent> <leader><space> :noh<cr>

"" Switching windows
noremap <C-j> <C-w>j
noremap <C-k> <C-w>k
noremap <C-l> <C-w>l
noremap <C-h> <C-w>h

"" Vmap for maintain Visual Mode after shifting > and <
vmap < <gv
vmap > >gv

"" Move visual block
vnoremap J :m '>+1<CR>gv=gv
vnoremap K :m '<-2<CR>gv=gv

init.lua

-- Install packer
local install_path = vim.fn.stdpath 'data' .. '/site/pack/packer/start/packer.nvim'
local is_bootstrap = false
if vim.fn.empty(vim.fn.glob(install_path)) > 0 then
  is_bootstrap = true
  vim.fn.system { 'git', 'clone', '--depth', '1', 'https://github.com/wbthomason/packer.nvim', install_path }
  vim.cmd [[packadd packer.nvim]]
end

require('packer').startup(function(use)
  -- Package manager
  use 'wbthomason/packer.nvim'

  use { -- LSP Configuration & Plugins
    'neovim/nvim-lspconfig',
    requires = {
      -- Automatically install LSPs to stdpath for neovim
      'williamboman/mason.nvim',
      'williamboman/mason-lspconfig.nvim',

      -- Useful status updates for LSP
      'j-hui/fidget.nvim',

      -- Additional lua configuration, makes nvim stuff amazing
      'folke/neodev.nvim',
    },
  }

  use 'nvim-lua/lsp-status.nvim'

  use { -- Autocompletion
    'hrsh7th/nvim-cmp',
    requires = { 'hrsh7th/cmp-nvim-lsp', 'L3MON4D3/LuaSnip', 'saadparwaiz1/cmp_luasnip' },
  }

  use { -- Highlight, edit, and navigate code
    'nvim-treesitter/nvim-treesitter',
    run = function()
      pcall(require('nvim-treesitter.install').update { with_sync = true })
    end,
  }

  use { -- Additional text objects via treesitter
    'nvim-treesitter/nvim-treesitter-textobjects',
    after = 'nvim-treesitter',
  }

  use {
    'nvim-tree/nvim-tree.lua',
    requires = { 'nvim-tree/nvim-web-devicons' }
  }
  -- Git related plugins
  use 'tpope/vim-fugitive'
  use 'tpope/vim-rhubarb'
  use 'lewis6991/gitsigns.nvim'

  use 'navarasu/onedark.nvim' -- Theme inspired by Atom
  use 'nvim-lualine/lualine.nvim' -- Fancier statusline
  use 'lukas-reineke/indent-blankline.nvim' -- Add indentation guides even on blank lines
  use 'numToStr/Comment.nvim' -- "gc" to comment visual regions/lines
  use 'tpope/vim-sleuth' -- Detect tabstop and shiftwidth automatically
  use 'tpope/vim-surround' -- surround with stuff

  use 'Raimondi/delimitMate'

  -- auto pairs
  use {
    "windwp/nvim-autopairs",
    config = function()
      local npairs = require("nvim-autopairs")
      npairs.setup({
        check_ts = true,
        enable_check_bracket_line = false,
        fast_wrap = {},
      })

      local cmp_autopairs = require('nvim-autopairs.completion.cmp')
      local cmp = require('cmp')
      cmp.event:on(
        'confirm_done',
        cmp_autopairs.on_confirm_done()
      )
    end
  }

  --- telescope search results pretify
  use {
    "folke/trouble.nvim",
    requires = "kyazdani42/nvim-web-devicons",
    config = function()
      require("trouble").setup {
        -- your configuration comes here
        -- or leave it empty to use the default settings
        -- refer to the configuration section below
      }
    end
  }

  use 'frazrepo/vim-rainbow'
  use 'kamykn/spelunker.vim'

  -- Fuzzy Finder (files, lsp, etc)
  use { 'nvim-telescope/telescope.nvim', branch = '0.1.x', requires = { 'nvim-lua/plenary.nvim' } }

  -- Fuzzy Finder Algorithm which requires local dependencies to be built. Only load if `make` is available
  use { 'nvim-telescope/telescope-fzf-native.nvim', run = 'make', cond = vim.fn.executable 'make' == 1 }

  use {
    'yuttie/comfortable-motion.vim',
  }

  use {
    'phaazon/hop.nvim',
    branch = 'v2' -- optional but strongly recommended
  }
  
  use { "akinsho/toggleterm.nvim", tag = '*', config = function()
    require("toggleterm").setup()
  end }

  use 'simrat39/rust-tools.nvim'

  -- Debugging
  use 'nvim-lua/plenary.nvim'
  use 'mfussenegger/nvim-dap'

  -- Add custom plugins to packer from ~/.config/nvim/lua/custom/plugins.lua
  local has_plugins, plugins = pcall(require, 'custom.plugins')
  if has_plugins then
    plugins(use)
  end

  if is_bootstrap then
    require('packer').sync()
  end
end)

-- When we are bootstrapping a configuration, it doesn't
-- make sense to execute the rest of the init.lua.
--
-- You'll need to restart nvim, and then it will work.
if is_bootstrap then
  print '=================================='
  print '    Plugins are being installed'
  print '    Wait until Packer completes,'
  print '       then restart nvim'
  print '=================================='
  return
end

-- Automatically source and re-compile packer whenever you save this init.lua
local packer_group = vim.api.nvim_create_augroup('Packer', { clear = true })
vim.api.nvim_create_autocmd('BufWritePost', {
  command = 'source <afile> | silent! LspStop | silent! LspStart | PackerCompile',
  group = packer_group,
  pattern = vim.fn.expand '$MYVIMRC',
})

local function map(mode, lhs, rhs, opts)
  local options = { noremap = true }
  if opts then
    options = vim.tbl_extend("force", options, opts)
  end
  vim.api.nvim_set_keymap(mode, lhs, rhs, options)
end

-- [[ Setting options ]]
-- See `:help vim.o`

vim.opt.guifont = { "Mona Sans Regular", "h15" }

-- Set highlight on search
vim.o.hlsearch = false

-- Make line numbers default
vim.wo.number = true

-- Enable mouse mode
vim.o.mouse = 'a'

-- Enable break indent
vim.o.breakindent = true

-- Save undo history
vim.o.undofile = true

-- Case insensitive searching UNLESS /C or capital in search
vim.o.ignorecase = true
vim.o.smartcase = true

-- Decrease update time
vim.o.updatetime = 250
vim.wo.signcolumn = 'yes'

-- Set colorscheme
vim.o.termguicolors = true
vim.cmd [[colorscheme onedark]]

-- Set completeopt to have a better completion experience
vim.o.completeopt = 'menuone,noselect'

-- [[ Basic Keymaps ]]
-- Set <space> as the leader key
-- See `:help mapleader`
--  NOTE: Must happen before plugins are required (otherwise wrong leader will be used)
vim.g.mapleader = ','
vim.g.maplocalleader = ','

-- Keymaps for better default experience
-- See `:help vim.keymap.set()`
vim.keymap.set({ 'n', 'v' }, '<Space>', '<Nop>', { silent = true })

-- Remap for dealing with word wrap
vim.keymap.set('n', 'k', "v:count == 0 ? 'gk' : 'k'", { expr = true, silent = true })
vim.keymap.set('n', 'j', "v:count == 0 ? 'gj' : 'j'", { expr = true, silent = true })


-- [[ Comfortable motion ]]
--
vim.g.comfortable_motion_scroll_down_key = "j"
vim.g.comfortable_motion_scroll_up_key = "k"
vim.g.comfortable_motion_no_default_key_mappings = 1

map('n', '<S-Up>', ':call comfortable_motion#flick(-50)<CR>', { silent = true })
map('n', '<S-Down>', ':call comfortable_motion#flick(50)<CR>', { silent = true })

-- [[ Highlight on yank ]]
-- See `:help vim.highlight.on_yank()`
local highlight_group = vim.api.nvim_create_augroup('YankHighlight', { clear = true })
vim.api.nvim_create_autocmd('TextYankPost', {
  callback = function()
    vim.highlight.on_yank()
  end,
  group = highlight_group,
  pattern = '*',
})

-- Set lualine as statusline
-- See `:help lualine.txt`
require('lualine').setup {
  options = {
    icons_enabled = false,
    theme = 'onedark',
    component_separators = '|',
    section_separators = '',
  },
}

-- Enable Comment.nvim
require('Comment').setup()

-- Enable `lukas-reineke/indent-blankline.nvim`
-- See `:help indent_blankline.txt`
require('indent_blankline').setup {
  char = '┊',
  show_trailing_blankline_indent = false,
}

-- Gitsigns
-- See `:help gitsigns.txt`
require('gitsigns').setup {
  signs = {
    add = { text = '+' },
    change = { text = '~' },
    delete = { text = '_' },
    topdelete = { text = '‾' },
    changedelete = { text = '~' },
  },
}

-- [[ Configure Telescope ]]
-- See `:help telescope` and `:help telescope.setup()`
require('telescope').setup {
  defaults = {
    mappings = {
      i = {
        ['<C-u>'] = false,
        ['<C-d>'] = false,
        ['<C-k>'] = false,
      },
    },
  },
}

-- Enable hop for easy motion
local hop = require('hop');
local directions = require('hop.hint').HintDirection

hop.setup()

vim.keymap.set('', 'f', function()
  hop.hint_char1({ direction = directions.AFTER_CURSOR, current_line_only = true })
end, { remap = true })

vim.keymap.set('', 'F', function()
  hop.hint_char1({ direction = directions.BEFORE_CURSOR, current_line_only = true })
end, { remap = true })

vim.keymap.set('n', '<leader>fv', hop.hint_vertical, { desc = "[H]op [V]ertical" })
vim.keymap.set('n', '<leader>fl', hop.hint_lines_skip_whitespace, { desc = "[H]op [L]ines" })
vim.keymap.set('n', '<leader>fw', hop.hint_words, { desc = "[H]op [L]ines" })

-- Enable telescope fzf native, if installed
pcall(require('telescope').load_extension, 'fzf')

-- See `:help telescope.builtin`
vim.keymap.set('n', '<leader>?', require('telescope.builtin').oldfiles, { desc = '[?] Find recently opened files' })
vim.keymap.set('n', '<leader><space>', require('telescope.builtin').buffers, { desc = '[ ] Find existing buffers' })
vim.keymap.set('n', '<leader>/', function()
  -- You can pass additional configuration to telescope to change theme, layout, etc.
  require('telescope.builtin').current_buffer_fuzzy_find(require('telescope.themes').get_dropdown {
    winblend = 10,
    previewer = false,
  })
end, { desc = '[/] Fuzzily search in current buffer]' })

vim.keymap.set('n', '<leader>sf', require('telescope.builtin').find_files, { desc = '[S]earch [F]iles' })
vim.keymap.set('n', '<leader>sh', require('telescope.builtin').help_tags, { desc = '[S]earch [H]elp' })
-- vim.keymap.set('n', '<leader>sw', require('telescope.builtin').grep_string, { desc = '[S]earch current [W]ord' })
vim.keymap.set('n', '<leader>sg', require('telescope.builtin').live_grep, { desc = '[S]earch by [G]rep' })
vim.keymap.set('n', '<leader>sr', require('telescope.builtin').resume, { desc = '[S]earch [R]esume' })
vim.keymap.set('n', '<leader>sd', require('telescope.builtin').diagnostics, { desc = '[S]earch [D]iagnostics' })
vim.keymap.set('n', '<leader>sm', ':Telescope lsp_document_symbols ignore_symbols=variable<CR>',
  { desc = '[S]earch [M]ethods' })
vim.keymap.set('n', '<leader>ss', ':Telescope lsp_document_symbols<CR>', { desc = '[S]earch [S]ymbols' })


-- [[ Configure Treesitter ]]
-- See `:help nvim-treesitter`
require('nvim-treesitter.configs').setup {
  -- Add languages to be installed here that you want installed for treesitter
  ensure_installed = { 'c', 'cpp', 'go', 'lua', 'python', 'rust', 'typescript', 'help', 'vim' },
  autopairs = {
    enable = true
  },

  highlight = { enable = true },
  indent = { enable = true, disable = { 'python' } },
  incremental_selection = {
    enable = true,
    keymaps = {
      init_selection = '<c-space>',
      node_incremental = '<c-space>',
      scope_incremental = '<c-s>',
      node_decremental = '<c-backspace>',
    },
  },
  textobjects = {
    select = {
      enable = true,
      lookahead = true, -- Automatically jump forward to textobj, similar to targets.vim
      keymaps = {
        -- You can use the capture groups defined in textobjects.scm
        ['aa'] = '@parameter.outer',
        ['ia'] = '@parameter.inner',
        ['af'] = '@function.outer',
        ['if'] = '@function.inner',
        ['ac'] = '@class.outer',
        ['ic'] = '@class.inner',
      },
    },
    move = {
      enable = true,
      set_jumps = true, -- whether to set jumps in the jumplist
      goto_next_start = {
        [']m'] = '@function.outer',
        [']]'] = '@class.outer',
      },
      goto_next_end = {
        [']M'] = '@function.outer',
        [']['] = '@class.outer',
      },
      goto_previous_start = {
        ['[m'] = '@function.outer',
        ['[['] = '@class.outer',
      },
      goto_previous_end = {
        ['[M'] = '@function.outer',
        ['[]'] = '@class.outer',
      },
    },
    swap = {
      enable = true,
      swap_next = {
        ['<leader>a'] = '@parameter.inner',
      },
      swap_previous = {
        ['<leader>A'] = '@parameter.inner',
      },
    },
  },
}

-- nvim-tree for file sidebar
require("nvim-tree").setup({
  sort_by = "case_sensitive",
  view = {
    adaptive_size = true,
    mappings = {
      list = {
        { key = "u", action = "dir_up" },
      },
    },
  },
  renderer = {
    group_empty = true,
  },
  filters = {
    dotfiles = true,
  },
})


vim.keymap.set('n', '<leader>nff', '<cmd>:NvimTreeFindFile<CR>', { desc = '[S]Nvimtree [F]ind [F]ile' })
vim.keymap.set('n', '<leader>nt', require('nvim-tree').toggle, { desc = '[S]Nvimtree [T]Toggle' })

-- Diagnostic keymaps
vim.keymap.set('n', '[d', vim.diagnostic.goto_prev)
vim.keymap.set('n', ']d', vim.diagnostic.goto_next)
vim.keymap.set('n', '<leader>e', vim.diagnostic.open_float)
vim.keymap.set('n', '<leader>q', vim.diagnostic.setloclist)

-- LSP settings.
--  This function gets run when an LSP connects to a particular buffer.
local on_attach = function(_, bufnr)
  -- NOTE: Remember that lua is a real programming language, and as such it is possible
  -- to define small helper and utility functions so you don't have to repeat yourself
  -- many times.
  --
  -- In this case, we create a function that lets us more easily define mappings specific
  -- for LSP related items. It sets the mode, buffer and description for us each time.
  local nmap = function(keys, func, desc)
    if desc then
      desc = 'LSP: ' .. desc
    end

    vim.keymap.set('n', keys, func, { buffer = bufnr, desc = desc })
  end

  nmap('<leader>rn', vim.lsp.buf.rename, '[R]e[n]ame')
  nmap('<leader>ca', vim.lsp.buf.code_action, '[C]ode [A]ction')

  nmap('gd', vim.lsp.buf.definition, '[G]oto [D]efinition')
  nmap('gr', require('telescope.builtin').lsp_references, '[G]oto [R]eferences')
  nmap('gI', vim.lsp.buf.implementation, '[G]oto [I]mplementation')

  nmap("<leader>xl", "<cmd>TroubleToggle loclist<cr>")
  nmap("<leader>xq", "<cmd>TroubleToggle quickfix<cr>")
  nmap("<leader>xr", "<cmd>TroubleToggle lsp_references<cr>")

  nmap('<leader>D', vim.lsp.buf.type_definition, 'Type [D]efinition')
  nmap('<leader>ds', require('telescope.builtin').lsp_document_symbols, '[D]ocument [S]ymbols')
  nmap('<leader>ws', require('telescope.builtin').lsp_dynamic_workspace_symbols, '[W]orkspace [S]ymbols')

  -- See `:help K` for why this keymap
  nmap('K', vim.lsp.buf.hover, 'Hover Documentation')
  nmap('<C-k>', vim.lsp.buf.signature_help, 'Signature Documentation')

  -- nvim-tree config

  -- Lesser used LSP functionality
  nmap('gD', vim.lsp.buf.declaration, '[G]oto [D]eclaration')
  nmap('<leader>wa', vim.lsp.buf.add_workspace_folder, '[W]orkspace [A]dd Folder')
  nmap('<leader>wr', vim.lsp.buf.remove_workspace_folder, '[W]orkspace [R]emove Folder')
  nmap('<leader>wl', function()
    print(vim.inspect(vim.lsp.buf.list_workspace_folders()))
  end, '[W]orkspace [L]ist Folders')

  vim.api.nvim_command("au BufWritePost <buffer> lua vim.lsp.buf.format({async = true})")

  -- Create a command `:Format` local to the LSP buffer
  vim.api.nvim_buf_create_user_command(bufnr, 'Format', function(_)
    vim.lsp.buf.format()
  end, { desc = 'Format current buffer with LSP' })
end


-- Enable the following language servers
--  Feel free to add/remove any LSPs that you want here. They will automatically be installed.
--
--  Add any additional override configuration in the following tables. They will be passed to
--  the `settings` field of the server config. You must look up that documentation yourself.
util = require "lspconfig/util"

local servers = {
  -- clangd = {},
  gopls = {},
  pyright = {},
  tsserver = {},
  vimls = {},
  -- sumneko_lua = {
  --   Lua = {
  --     workspace = { checkThirdParty = false },
  --     telemetry = { enable = false },
  --   },
  -- },
}

-- Setup neovim lua configuration
require('neodev').setup()
--
-- nvim-cmp supports additional completion capabilities, so broadcast that to servers
local capabilities = vim.lsp.protocol.make_client_capabilities()
capabilities = require('cmp_nvim_lsp').default_capabilities(capabilities)

-- Setup rust tools
require("rust-tools").setup({
  tools = {
    autoSetHints = true,
    inlay_hints = {
      show_parameter_hints = true,
      parameter_hints_prefix = "",
      other_hints_prefix = "",
    },
  },
  server = {
    settings = {
      ["rust-analyzer"] = servers["rust_analyzer"],
    }
  }
})

-- Setup mason so it can manage external tooling
require('mason').setup()

-- Ensure the servers above are installed
local mason_lspconfig = require 'mason-lspconfig'

mason_lspconfig.setup {
  ensure_installed = vim.tbl_keys(servers),
}

mason_lspconfig.setup_handlers {
  function(server_name)
    require('lspconfig')[server_name].setup {
      capabilities = capabilities,
      on_attach = on_attach,
      settings = servers[server_name],
    }
  end,
}

require('lspconfig').sumneko_lua.setup({
  capabilities = capabilities,
  on_attach = on_attach,
  settings = {
    Lua = {
      runtime = {
        version = 'LuaJIT',
      },
      diagnostics = {
        -- Get the language server to recognize the `vim` global
        globals = { 'vim' },
      },
      workspace = {
        library = vim.api.nvim_get_runtime_file("", true),
        checkThirdParty = false,
      },
      -- Do not send telemetry data containing a randomized but unique identifier
      telemetry = {
        enable = false,
      },
    },
  },
})

-- Turn on lsp status information
require('fidget').setup()

-- nvim-cmp setup
local cmp = require 'cmp'
local luasnip = require 'luasnip'

cmp.setup {
  snippet = {
    expand = function(args)
      luasnip.lsp_expand(args.body)
    end,
  },
  mapping = cmp.mapping.preset.insert {
    ['<C-d>'] = cmp.mapping.scroll_docs(-4),
    ['<C-f>'] = cmp.mapping.scroll_docs(4),
    ['<C-Space>'] = cmp.mapping.complete(),
    ['<CR>'] = cmp.mapping.confirm {
      behavior = cmp.ConfirmBehavior.Replace,
      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()
      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 = {
    { name = 'nvim_lsp' },
    { name = 'luasnip' },
  },
}

-- disable netrw at the very start of your init.lua (strongly advised)
vim.g.loaded_netrw = 1
vim.g.loaded_netrwPlugin = 1

-- set termguicolors to enable highlight groups
vim.opt.termguicolors = true


function go_org_imports(wait_ms)
  local params = vim.lsp.util.make_range_params()
  params.context = { only = { "source.organizeImports" } }
  local result = vim.lsp.buf_request_sync(0, "textDocument/codeAction", params, wait_ms)
  for cid, res in pairs(result or {}) do
    for _, r in pairs(res.result or {}) do
      if r.edit then
        local enc = (vim.lsp.get_client_by_id(cid) or {}).offset_encoding or "utf-16"
        vim.lsp.util.apply_workspace_edit(r.edit, enc)
      end
    end
  end
end

vim.cmd('autocmd BufWritePre *.go :silent! lua go_org_imports(2000)')

-- The line beneath this is called `modeline`. See `:help modeline`
-- vim: ts=2 sts=2 sw=2 et
--

vim.cmd('source ~/.config/nvim/base.mapping.vim')

Update your neovim to 0.8+ . Open neovim and run :PackerInstall