feat: add snippet support

Add go snippets (finally)

lua/custom/completion.lua

@@ -1,7 +1,7 @@
 local cmp = require("cmp")
 local defaults = require("cmp.config.default")()
 local lspkind = require "lspkind"
-lspkind.init {}
+require("custom.snippets")
 
 cmp.setup({
 	completion = {
@@ -31,4 +31,22 @@ cmp.setup({
 		{ name = "buffer" },
 	}),
 	sorting = defaults.sorting,
+	format = lspkind.cmp_format({
+		mode = 'text_symbol', -- show only symbol annotations
+		maxwidth = {
+			-- prevent the popup from showing more than provided characters (e.g 50 will not show more than 50 characters)
+			-- can also be a function to dynamically calculate max width such as
+			-- menu = function() return math.floor(0.45 * vim.o.columns) end,
+			menu = 50,          -- leading text (labelDetails)
+			abbr = 50,          -- actual suggestion item
+		},
+		ellipsis_char = '...',  -- when popup menu exceed maxwidth, the truncated part would show ellipsis_char instead (must define maxwidth first)
+		show_labelDetails = true, -- show labelDetails in menu. Disabled by default
+
+		-- The function below will be called before any actual modifications from lspkind
+		-- so that you can provide more controls on popup customization. (See [#30](https://github.com/onsails/lspkind-nvim/pull/30))
+		before = function(_, vim_item)
+			return vim_item
+		end
+	})
 })

lua/custom/snippets.lua

@@ -0,0 +1,48 @@
+local ls = require "luasnip"
+
+vim.snippet.expand = ls.lsp_expand
+
+---@diagnostic disable-next-line: duplicate-set-field
+vim.snippet.active = function(filter)
+  filter = filter or {}
+  filter.direction = filter.direction or 1
+
+  if filter.direction == 1 then
+    return ls.expand_or_jumpable()
+  else
+    return ls.jumpable(filter.direction)
+  end
+end
+
+---@diagnostic disable-next-line: duplicate-set-field
+vim.snippet.jump = function(direction)
+  if direction == 1 then
+    if ls.expandable() then
+      return ls.expand_or_jump()
+    else
+      return ls.jumpable(1) and ls.jump(1)
+    end
+  else
+    return ls.jumpable(-1) and ls.jump(-1)
+  end
+end
+
+vim.snippet.stop = ls.unlink_current
+
+ls.config.set_config {
+  history = true,
+  updateevents = "TextChanged,TextChangedI",
+  override_builtin = true,
+}
+
+for _, ft_path in ipairs(vim.api.nvim_get_runtime_file("lua/custom/snippets/*.lua", true)) do
+  loadfile(ft_path)()
+end
+
+vim.keymap.set({ "i", "s" }, "<c-j>", function()
+  return vim.snippet.active { direction = 1 } and vim.snippet.jump(1)
+end, { silent = true })
+
+vim.keymap.set({ "i", "s" }, "<c-k>", function()
+  return vim.snippet.active { direction = -1 } and vim.snippet.jump(-1)
+end, { silent = true })

lua/custom/snippets/go.lua

@@ -0,0 +1,53 @@
+require("luasnip.session.snippet_collection").clear_snippets "go"
+
+local ls = require "luasnip"
+
+local s = ls.snippet
+local i = ls.insert_node
+
+local fmt = require("luasnip.extras.fmt").fmt
+
+ls.add_snippets("go", {
+	s("fmt debug", fmt('fmt.Println("[DEBUG] {}", {})', { i(1), i(2) })),
+	s("fmt info", fmt('fmt.Println("[INFO] {}", {})', { i(1), i(2) })),
+	s("fmt error", fmt('fmt.Println("[ERROR] {}", {})', { i(1), i(2) })),
+	s("fmt warn", fmt('fmt.Println("[WARN] {}", {})', { i(1), i(2) })),
+
+	s("if err !=", fmt([[
+	if err != nil {{
+		return err
+	}}
+
+	]], {})),
+
+	s("if err :=", fmt([[
+	if err := {}; err != nil {{
+		return err
+	}}
+
+	]], { i(1) })),
+
+	s("json unmarshal", fmt([[
+	var {var_name} {}
+	if err := json.Unmarshal({}, &{var_name}); err != nil {{
+		return err
+	}}
+
+	]], { var_name = i(1), i(2), i(3) }, { repeat_duplicates = true })),
+
+	s("json decode", fmt([[
+	var {var_name} {}
+	if err := json.NewDecoder({}).Decode(&{var_name}); err != nil {{
+		return err
+	}}
+
+	]], { var_name = i(1), i(2), i(3) }, { repeat_duplicates = true })),
+
+	s("func", fmt([[
+	func {}({}) {} {{
+		{}
+	}}
+
+	]], { i(1), i(2), i(3), i(4) })),
+})
+