Investigate what can be useful from the old Nvim LSP configuration

[micku]

local on_attach = function(client, bufnr)
  local function buf_set_keymap(...) vim.api.nvim_buf_set_keymap(bufnr, ...) end

  -- Mappings.
  local opts = { noremap=true, silent=true }

  buf_set_keymap('n', 'gi', '<cmd>lua vim.lsp.buf.implementation()<CR>', opts)
  buf_set_keymap('n', 'gs', '<cmd>lua require("lspsaga.signaturehelp").signature_help()<CR>', opts)
  buf_set_keymap('n', '<Leader>wa', '<cmd>lua vim.lsp.buf.add_workspace_folder()<CR>', opts)
  buf_set_keymap('n', '<Leader>wr', '<cmd>lua vim.lsp.buf.remove_workspace_folder()<CR>', opts)
  buf_set_keymap('n', '<Leader>wl', '<cmd>lua print(vim.inspect(vim.lsp.buf.list_workspace_folders()))<CR>', opts)
  buf_set_keymap('n', 'gt', '<cmd>lua vim.lsp.buf.type_definition()<CR>', opts)
  buf_set_keymap('n', '<Leader>rn', '<cmd>lua require("lspsaga.rename").rename()<CR>', opts)
  buf_set_keymap('n', 'gr', '<cmd>lua vim.lsp.buf.references()<CR>', opts)
  buf_set_keymap('n', '<Leader>ee', '<cmd>lua vim.lsp.diagnostic.show_line_diagnostics()<CR>', opts)
  buf_set_keymap('n', '[d', '<cmd>lua vim.lsp.diagnostic.goto_prev()<CR>', opts)
  buf_set_keymap('n', ']d', '<cmd>lua vim.lsp.diagnostic.goto_next()<CR>', opts)
  buf_set_keymap('n', '<Leader>q', '<cmd>lua vim.lsp.diagnostic.set_loclist()<CR>', opts)
  buf_set_keymap('n', 'gh', '<cmd>lua require"lspsaga.provider".lsp_finder()<CR>', opts)
  buf_set_keymap('n', '<Leader>ca', '<cmd>lua require("lspsaga.codeaction").code_action()<CR>', opts)
  buf_set_keymap('v', '<Leader>ca', ':<C-U>lua require("lspsaga.codeaction").range_code_action()<CR>', opts)
  buf_set_keymap('n', '<leader>cd', '<cmd>lua require"lspsaga.diagnostic".show_line_diagnostics()<CR>', opts)
  buf_set_keymap('n', '<leader>cc', '<cmd>lua require"lspsaga.diagnostic".show_cursor_diagnostics()<CR>', opts)
  buf_set_keymap('n', '[e', '<cmd>lua require"lspsaga.diagnostic".lsp_jump_diagnostic_prev()<CR>', opts)
  buf_set_keymap('n', ']e', '<cmd>lua require"lspsaga.diagnostic".lsp_jump_diagnostic_next()<CR>', opts)

  -- Set autocommands conditional on server_capabilities
  if client.server_capabilities.document_highlight then
    vim.api.nvim_exec([[
      hi LspReferenceRead cterm=bold ctermbg=red guibg=LightYellow
      hi LspReferenceText cterm=bold ctermbg=red guibg=LightYellow
      hi LspReferenceWrite cterm=bold ctermbg=red guibg=LightYellow
      augroup lsp_document_highlight
        autocmd! * <buffer>
        autocmd CursorHold <buffer> lua vim.lsp.buf.document_highlight()
        autocmd CursorMoved <buffer> lua vim.lsp.buf.clear_references()
      augroup END
    ]], false)
  end
end