config.nvim/lua/plugins/cmp.lua

require("luasnip.loaders.from_vscode").lazy_load()

local has_words_before = function()
	unpack = unpack or table.unpack
	local line, col = unpack(vim.api.nvim_win_get_cursor(0))
	return col ~= 0 and vim.api.nvim_buf_get_lines(0, line - 1, line, true)[1]:sub(col, col):match("%s") == nil
end

local luasnip = require("luasnip")
local cmp = require("cmp")

cmp.setup({
	-- ... Your other configuration ...
	snippet = {
		-- REQUIRED - you must specify a snippet engine
		expand = function(args)
			-- vim.fn["vsnip#anonymous"](args.body) -- For `vsnip` users.
			require('luasnip').lsp_expand(args.body) -- For `luasnip` users.
			-- require('snippy').expand_snippet(args.body) -- For `snippy` users.
			-- vim.fn["UltiSnips#Anon"](args.body) -- For `ultisnips` users.
		end,
	},
	mapping = {
		    ["<Tab>"] = cmp.mapping(function(fallback)
			if cmp.visible() then
				cmp.select_next_item()
				-- You could replace the expand_or_jumpable() calls with expand_or_locally_jumpable()
				-- they way you will only jump inside the snippet region
			elseif luasnip.expand_or_jumpable() then
				luasnip.expand_or_jump()
			elseif has_words_before() then
				cmp.complete()
			else
				fallback()
			end
		end, { "i", "s" }),
		    ["<S-Tab>"] = cmp.mapping(function(fallback)
			if cmp.visible() then
				cmp.select_prev_item()
			elseif luasnip.jumpable(-1) then
				luasnip.jump(-1)
			else
				fallback()
			end
		end, { "i", "s" }),
		    ['<C-b>'] = cmp.mapping.scroll_docs(-4),
		    ['<C-f>'] = cmp.mapping.scroll_docs(4),
		    ['<C-Space>'] = cmp.mapping.complete(),
		    ['<C-e>'] = cmp.mapping.abort(),
		    ['<CR>'] = cmp.mapping.confirm({ select = true }), -- Accept currently selected item. Set `select` to `false` to only confirm explicitly selected items
		-- ... Your other mappings ...
	},
	sources = cmp.config.sources({
		{ name = "nvim_lsp" },
		{ name = "treesitter" },
		{ name = "buffer" },
		{ name = "luasnip" }, -- For luasnip users.
		{ name = "path" },
		{ name = "git" },
		{ name = "ctags" },
	})
	-- ... Your other configuration ...
})

cmp.setup.cmdline({ '/', '?' }, {
	mapping = cmp.mapping.preset.cmdline(),
	sources = {
		{ name = 'buffer' }
	}
})

-- Set configuration for specific filetype.
cmp.setup.filetype('gitcommit', {
	sources = cmp.config.sources({
		{ name = 'cmp_git' }, -- You can specify the `cmp_git` source if you were installed it.
	}, {
		{ name = 'buffer' },
	})
})

-- `:` cmdline setup.
cmp.setup.cmdline(':', {
	mapping = cmp.mapping.preset.cmdline(),
	sources = cmp.config.sources({
		{ name = 'path' }
	}, {
		{
			name = 'cmdline',
			option = {
				ignore_cmds = { 'Man', '!' }
			}
		}
	})
})