neovim/plugins/lsp/lspconfig.lua

local lsp_config = require("lspconfig")

-- always show signcolumns
vim.opt.signcolumn = "yes"

-- Mappings.
-- See `:help vim.diagnostic.*` for documentation on any of the below functions
local opts = { noremap = true, silent = true }
vim.keymap.set("n", "<space>e", vim.diagnostic.open_float, opts)
vim.keymap.set("n", "[c", vim.diagnostic.goto_prev, opts)
vim.keymap.set("n", "]c", vim.diagnostic.goto_next, opts)
vim.keymap.set("n", "<space>q", vim.diagnostic.setloclist, opts)

-- Use an on_attach function to only map the following keys
-- after the language server attaches to the current buffer
local on_attach = function(client, bufnr)
	-- Enable completion triggered by <c-x><c-o>
	-- vim.api.nvim_buf_set_option(bufnr, "omnifunc", "v:lua.vim.lsp.omnifunc")

	-- Mappings.
	-- See `:help vim.lsp.*` for documentation on any of the below functions
	local bufopts = { noremap = true, silent = true, buffer = bufnr }
	vim.keymap.set("n", "gD", vim.lsp.buf.declaration, bufopts)
	vim.keymap.set("n", "gd", vim.lsp.buf.definition, bufopts)
	vim.keymap.set("n", "gy", vim.lsp.buf.type_definition, bufopts)
	vim.keymap.set("n", "gr", vim.lsp.buf.references, bufopts)
	vim.keymap.set("n", "gi", vim.lsp.buf.implementation, bufopts)
	vim.keymap.set("n", "K", vim.lsp.buf.hover, bufopts)
	vim.keymap.set("n", "<C-k>", vim.lsp.buf.signature_help, bufopts)
	vim.keymap.set("n", "<space>wa", vim.lsp.buf.add_workspace_folder, bufopts)
	vim.keymap.set("n", "<space>wr", vim.lsp.buf.remove_workspace_folder, bufopts)
	vim.keymap.set("n", "<space>wl", function()
		print(vim.inspect(vim.lsp.buf.list_workspace_folders()))
	end, bufopts)
	vim.keymap.set("n", "<localleader>n", vim.lsp.buf.rename, bufopts)
	vim.keymap.set("n", "<localleader>a", vim.lsp.buf.code_action, bufopts)
	vim.keymap.set("n", "<localleader>f", vim.lsp.buf.formatting, bufopts)
end

-- nvim-cmp
local capabilities = vim.lsp.protocol.make_client_capabilities()
capabilities = require("cmp_nvim_lsp").update_capabilities(capabilities)

-------------------------------------------------------------------------------
-- See: https://github.com/neovim/nvim-lspconfig/blob/master/doc/server_configurations.md
--

-- Override the default configuration to be applied to all servers
lsp_config.util.default_config = vim.tbl_extend("force", lsp_config.util.default_config, {
	on_attach = on_attach,
	capabilities = capabilities,
})

-- nix
lsp_config.nil_ls.setup({})

-- js,ts
lsp_config.tsserver.setup({})
lsp_config.eslint.setup({})

-- rust
lsp_config.rust_analyzer.setup({
	-- Server-specific settings...
	settings = {
		["rust-analyzer"] = {
			["server.path"] = "rust-analyzer",
			["updates.prompt"] = false,
			["updates.checkOnStartup"] = false,
			["checkOnSave.enable"] = true,
			["checkOnSave.command"] = "clippy",
			["cargo.autoreload"] = true,
		},
	},
})