darkrc/vim/lua/on_lsp_attach.lua

local opts = { noremap=true, silent=true }

return function(_, 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', 'K', vim.lsp.buf.hover, bufopts)
	vim.keymap.set('n', 'gi', vim.lsp.buf.implementation, bufopts)
	vim.keymap.set('n', '<C-k>', vim.lsp.buf.signature_help, bufopts)

	vim.keymap.set('n', '<leader>wa', vim.lsp.buf.add_workspace_folder, bufopts)
	vim.keymap.set('n', '<leader>wr', vim.lsp.buf.remove_workspace_folder, bufopts)
	vim.keymap.set('n', '<leader>wl', function()
		print(vim.inspect(vim.lsp.buf.list_workspace_folders()))
	end, bufopts)

	vim.api.nvim_buf_create_user_command(bufnr, "LspSetWorkspace", function()
		for i, workspace in ipairs(vim.lsp.buf.list_workspace_folders()) do
			vim.lsp.buf.remove_workspace_folder(workspace)
		end
		vim.lsp.buf.add_workspace_folder(vim.cmd("pwd"))
	end, {})

	vim.keymap.set('n', '<leader>D', vim.lsp.buf.type_definition, bufopts)
	vim.keymap.set('n', '<leader>r', vim.lsp.buf.rename, bufopts)
	vim.keymap.set('n', '<leader>ca', vim.lsp.buf.code_action, bufopts)
	vim.keymap.set('n', 'gr', vim.lsp.buf.references, bufopts)
	--vim.keymap.set('n', '<leader>f', vim.lsp.buf.formatting, bufopts)

	vim.api.nvim_buf_create_user_command(bufnr, "Format", vim.lsp.buf.format, {})
end