nvim: plugins/lsp: Drop null-ls

See the below issue
https://github.com/jose-elias-alvarez/nvim-lsp-ts-utils/issues/87

We went with null-ls because we wanted formatting with prettier. Also
null-ls was recommended by nvim-lsp-ts-utils.

The advantage of null-ls is it provides formatting and diagnostics
together in one package.

However, we will get prettier by another means and for linting switch to
nvim-lint.

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

@@ -1,7 +1,6 @@
 local nvim_lsp   = require 'lspconfig'
 local protocol   = require 'vim.lsp.protocol'
 local ts_utils   = require 'nvim-lsp-ts-utils'
-local null_ls    = require 'null-ls'
 local util       = require 'lspconfig/util'
 local cmp        = require 'cmp_nvim_lsp'
 
@@ -31,19 +30,9 @@ function PeekDefinition()
   return vim.lsp.buf_request(0, 'textDocument/definition', params, preview_location_callback)
 end
 
--- This should be called only once, so cannot be in on_attach as earlier.
--- See https://github.com/jose-elias-alvarez/null-ls.nvim/issues/38
--- Required by nvim-lsp-ts-utils to provide ESLint code actions, diagnostics
--- and formatting.
-local null_ls_sources = {
-    null_ls.builtins.diagnostics.shellcheck,
-}
-null_ls.config({ sources = null_ls_sources })
-nvim_lsp["null-ls"].setup {}
-
 local ts_utils_setup = function(client, bufnr, opts)
   if client.name == 'tsserver' then
-    -- Disable tsserver formatting as we plan on formatting via null-ls
+    -- Disable tsserver formatting, we want formatting via prettier
     client.resolved_capabilities.document_formatting       = false
     client.resolved_capabilities.document_range_formatting = false
 
@@ -62,17 +51,6 @@ local ts_utils_setup = function(client, bufnr, opts)
         same_file      = 1, -- add to existing import statement
       },
 
-      eslint_enable_code_actions     = true,
-      eslint_bin                     = "eslint",
-      eslint_enable_disable_comments = true,
-      eslint_enable_diagnostics      = true,
-      eslint_config_fallback         = nil,
-      eslint_show_rule_id            = false,
-
-      enable_formatting              = true,
-      formatter                      = "prettier",
-      formatter_config_fallback      = nil,
-
       update_imports_on_move         = false,
       require_confirmation_on_move   = false,
       watch_dir                      = nil,
@@ -103,6 +81,10 @@ local on_attach = function(client, bufnr)
 
   local opts = { noremap=true, silent=true }
 
+  -- This needs to be here, so we disable formatting with tsserver before
+  -- actually checking it below.
+  ts_utils_setup(client, bufnr, opts)
+
   vim.api.nvim_buf_set_keymap(bufnr, 'n', 'gd'       , '<cmd>lua vim.lsp.buf.definition()<CR>'       , opts)
   vim.api.nvim_buf_set_keymap(bufnr, 'n', 'gD'       , '<cmd>lua vim.lsp.buf.declaration()<CR>'      , opts)
   vim.api.nvim_buf_set_keymap(bufnr, 'n', 'gr'       , '<cmd>lua vim.lsp.buf.references()<CR>'       , opts)
@@ -163,8 +145,6 @@ local on_attach = function(client, bufnr)
     ' '; -- type parameter
   }
 
-  ts_utils_setup(client, bufnr, opts)
-
   vim.cmd [[autocmd CursorHold,CursorHoldI <buffer> lua require'nvim-lightbulb'.update_lightbulb()]]
 end
 

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

@@ -82,10 +82,7 @@ local init = function ()
   -- Alignment
   use 'junegunn/vim-easy-align'
   use 'nvim-lua/plenary.nvim'
-  use {
+  use 'jose-elias-alvarez/nvim-lsp-ts-utils'
-    'jose-elias-alvarez/nvim-lsp-ts-utils',
-    requires = { 'jose-elias-alvarez/null-ls.nvim' }
-  }
   -- LSP
   use {
     'neovim/nvim-lspconfig',