nvim: Switch to nvim-cmp

nvim-compe has been deprecated. While we tried to make it a few days
without any completion support, in javascript/typescript could not get
the default omnicompletion to work at all. It is possible that this
could be due to nvim-lsp-ts-utils/null-ls but who is gonna debug.

Also tried MUcomplete but it just would not work. There are open issues
on this. See https://github.com/neovim/neovim/issues/12390 and also
https://github.com/lifepillar/vim-mucomplete/issues/179.

So here we are with nvim-cmp. Some observations in comparison to compe
before. Using buffer completion seems not possible as most of the times
LSP completion items then do not turn up. Do not know if this is server
specific but at least it is the case with Rust. compe seemed better
performance wise especially in tsserver and considering the buffer
problem mentioned above. Also, even with vsnip added as the completion
source can't seem to get any snippet specific completions working.

Could have ditched all completion support if I did not have to use
tsserver but need it for work currently. So we will stick to enabling
this and hopefully it improves in future.

Fuck nodejs, javascript and typescript.

For references see,
https://github.com/kristijanhusak/neovim-config
https://github.com/sQVe/dotfiles/tree/master/config/nvim

nvim/.config/nvim/after/plugin/cmp.lua

@@ -0,0 +1,54 @@
+local cmp     = require 'cmp'
+local lspkind = require 'lspkind'
+
+cmp.setup {
+  formatting = {
+    format = function(entry, vim_item)
+      vim_item.menu = ({
+        buffer   = '[Buffer]',
+        nvim_lsp = '[Lsp]',
+        nvim_lua = '[Lua]',
+        path     = '[Path]',
+        vsnip    = '[Snippet]',
+      })[entry.source.name]
+      vim_item.kind = lspkind.presets.default[vim_item.kind]
+      return vim_item
+    end,
+  },
+  snippet = {
+    expand = function (args)
+      vim.fn["vsnip#anonymous"](args.body)
+    end
+  },
+  documentation = {
+    border = 'rounded'
+  },
+  mapping = {
+    ['<CR>'] = cmp.mapping.confirm({
+      behavior = cmp.ConfirmBehavior.Replace,
+      select = true
+    }),
+  },
+  sources = {
+    {
+      name = 'nvim_lsp',
+      priority = 100
+    },
+    {
+      name = 'vsnip',
+      priority = 80
+    },
+    {
+      name = 'nvim_lua',
+      priority = 50
+    },
+    {
+      name = 'buffer',
+      priority = 20
+    },
+    {
+      name = 'path',
+      priority = 5
+    },
+  }
+}

nvim/.config/nvim/after/plugin/completion.lua

@@ -1,82 +0,0 @@
-local remap = vim.api.nvim_set_keymap
-
-require'compe'.setup {
-  enabled              = true;
-  autocomplete         = false;
-  debug                = false;
-  min_length           = 1;
-  preselect            = 'enable';
-  throttle_time        = 80;
-  source_timeout       = 200;
-  resolve_timeout      = 800;
-  incomplete_delay     = 400;
-  max_abbr_width       = 100;
-  max_kind_width       = 100;
-  max_menu_width       = 100;
-  documentation  = {
-    border       = { '', '' ,'', ' ', '', '', '', ' ' },
-    winhighlight = "NormalFloat:CompeDocumentation,FloatBorder:CompeDocumentationBorder",
-    max_width    = 120,
-    min_width    = 60,
-    max_height   = math.floor(vim.o.lines * 0.3),
-    min_height   = 1,
-  };
-
-  source = {
-    path          = true;
-    buffer        = true;
-    calc          = true;
-    nvim_lsp      = true;
-    nvim_lua      = true;
-    omni          = false;
-    spell         = true;
-    tags          = false;
-    treesitter    = true;
-    snippets_nvim = false;
-    vsnip         = true;
-    ultisnips     = false;
-    luasnip       = false;
-    emoji         = false;
-  };
-}
-
-local t = function(str)
-  return vim.api.nvim_replace_termcodes(str, true, true, true)
-end
-
-local check_back_space = function()
-  local col = vim.fn.col('.') - 1
-  if col == 0 or vim.fn.getline('.'):sub(col, col):match('%s') then
-    return true
-  else
-    return false
-  end
-end
-
--- Use (S-)tab to:
--- Move to prev/next item in completion menuone
-
-_G.tab_complete = function()
-  if vim.fn.pumvisible() == 1 then
-    return t "<C-n>"
-  elseif vim.fn.call("vsnip#available", {1}) == 1 then
-    return t "<Plug>(vsnip-expand-or-jump)"
-  elseif check_back_space() then
-    return t "<Tab>"
-  else
-    return vim.fn['compe#complete']()
-  end
-end
-
-_G.s_tab_complete = function()
-  if vim.fn.pumvisible() == 1 then
-    return t "<C-p>"
-  else
-    return t "<S-Tab>"
-  end
-end
-
-remap("i", "<Tab>", "v:lua.tab_complete()", {expr = true})
-remap("s", "<Tab>", "v:lua.tab_complete()", {expr = true})
-remap("i", "<S-Tab>", "v:lua.s_tab_complete()", {expr = true})
-remap("s", "<S-Tab>", "v:lua.s_tab_complete()", {expr = true})

nvim/.config/nvim/lua/lsp.lua

@@ -168,7 +168,7 @@ function set_snippet_capabilities()
       'additionalTextEdits',
     }
   }
-  return capabilities
+  return require('cmp_nvim_lsp').update_capabilities(capabilities)
 end
 
 -- This should be called only once, so cannot be in on_attach as earlier.
@@ -188,6 +188,7 @@ end
 
 nvim_lsp.clangd.setup {
   on_attach = on_attach,
+  capabilities = set_snippet_capabilities(),
   default_config = {
     cmd = { "clangd", "--background-index", "--pch-storage=memory", "--clang-tidy", "--suggest-missing-includes" },
     filetypes = { 'c', 'cpp' },
@@ -283,6 +284,7 @@ table.insert(runtime_path, "lua/?/init.lua")
 nvim_lsp.sumneko_lua.setup {
   cmd = { "/usr/bin/lua-language-server" };
   on_attach = on_attach,
+  capabilities = set_snippet_capabilities(),
   settings = {
     Lua = {
       runtime = {

nvim/.config/nvim/lua/plugins.lua

@@ -19,7 +19,17 @@ local init = function ()
   -- Manage Project sessions
   use 'thaerkh/vim-workspace'
   -- For autocompletion
-  use 'hrsh7th/nvim-compe'
+  use {
+    'hrsh7th/nvim-cmp',
+    requires = {
+      'hrsh7th/cmp-nvim-lsp',
+      'hrsh7th/cmp-nvim-lua',
+      'hrsh7th/cmp-buffer',
+      'hrsh7th/cmp-vsnip',
+      'hrsh7th/cmp-path',
+      'onsails/lspkind-nvim'
+    }
+  }
   -- Git support
   use 'lewis6991/gitsigns.nvim'
   use 'tpope/vim-fugitive'