neovim-confs/lua/plugins/configs/lspconfig.lua

local M = {}
require("plugins.configs.others").lsp_handlers()

function M.on_attach(client, bufnr)
   local function buf_set_option(...)
      vim.api.nvim_buf_set_option(bufnr, ...)
   end

   client.resolved_capabilities.document_formatting = false
   client.resolved_capabilities.document_range_formatting = false
   -- Enable completion triggered by <c-x><c-o>
   buf_set_option("omnifunc", "v:lua.vim.lsp.omnifunc")

   require("core.mappings").lspconfig()
end

local capabilities = vim.lsp.protocol.make_client_capabilities()
capabilities.textDocument.completion.completionItem.documentationFormat = { "markdown", "plaintext" }
capabilities.textDocument.completion.completionItem.snippetSupport = true
capabilities.textDocument.completion.completionItem.preselectSupport = true
capabilities.textDocument.completion.completionItem.insertReplaceSupport = true
capabilities.textDocument.completion.completionItem.labelDetailsSupport = true
capabilities.textDocument.completion.completionItem.deprecatedSupport = true
capabilities.textDocument.completion.completionItem.commitCharactersSupport = true
capabilities.textDocument.completion.completionItem.tagSupport = { valueSet = { 1 } }
capabilities.textDocument.completion.completionItem.resolveSupport = {
   properties = {
      "documentation",
      "detail",
      "additionalTextEdits",
   },
}

-- requires a file containing user's lspconfigs
local addlsp_confs = require("core.utils").load_config().plugins.options.lspconfig.setup_lspconf

if #addlsp_confs ~= 0 then
   require(addlsp_confs).setup_lsp(M.on_attach, capabilities)
end

return M