Apply easy suggestions (part4)

lua/luasnip/extras/fmt.lua

@@ -23,7 +23,8 @@ local rp = require("luasnip.extras").rep
 ---   counting from the new value (e.g. `{} {3} {}` is `{1} {3} {4}`)
 ---
 ---@param fmt string String with placeholders
----@param args {[integer|string]: LuaSnip.Node} Table with list-like and/or map-like keys
+---@param args LuaSnip.Node[]|{[string]: LuaSnip.Node} Table with list-like
+---  and/or map-like keys
 ---@param opts? LuaSnip.Opts.Extra.FmtInterpolate
 ---@return (string|LuaSnip.Node)[] _ A list of strings & elements of `args`
 ---  inserted into placeholders.
@@ -175,7 +176,7 @@ end
 --- See `interpolate` documentation for details on the format.
 ---
 ---@param str string The format string
----@param nodes LuaSnip.Node|LuaSnip.Node[]
+---@param nodes LuaSnip.Node|LuaSnip.Node[]|{[string]: LuaSnip.Node}
 ---@param opts? LuaSnip.Opts.Extra.Fmt
 ---@return LuaSnip.Node[]
 local function format_nodes(str, nodes, opts)

lua/luasnip/nodes/functionNode.lua

@@ -206,8 +206,7 @@ function FunctionNode:indent(_) end
 function FunctionNode:expand_tabs(_) end
 
 function FunctionNode:make_args_absolute(position_so_far)
-	self.args_absolute = {}
-	node_util.make_args_absolute(self.args, position_so_far, self.args_absolute)
+	self.args_absolute = node_util.make_args_absolute(self.args, position_so_far)
 end
 
 function FunctionNode:set_dependents()

lua/luasnip/nodes/node.lua

@@ -29,8 +29,9 @@ local describe = require("luasnip.util.log").describe
 ---  snippet node.
 ---@field indx integer Index of the node in the snippet or snippet node.
 ---
+---(FIXME(@L3MON4D3): Document these)
 ---@field visible boolean
----@field static_text string[] (FIXME(@bew): What is this for?)
+---@field static_text string[]
 ---@field static_visible boolean
 ---@field visited boolean
 ---@field old_text ... (?)

lua/luasnip/nodes/snippet.lua

@@ -336,7 +336,12 @@ local function init_snippet_context(context, opts)
 			util.ternary(context.regTrig ~= nil, "pattern", "plain")
 		)
 		engine = trig_engines[engine_name]
+		if not engine then
+		  error("Unknown trigEngine '".. engine_name.."'")
+		end
 	end
+	---@cast engine -nil (We know it's valid here)
+
 	-- make sure to pass through nil-trigEngineOpts, they will be recognized and
 	-- we will get a default-version of that function instead of generating a
 	-- curried (?) version of it (which would waste space I think).

lua/luasnip/nodes/util.lua

@@ -44,23 +44,25 @@ end
 
 ---@param args LuaSnip.NodeRef[]
 ---@param parent_insert_position integer[]
----@param target LuaSnip.NormalizedNodeRef[] Target for the normalized node refs
--- FIXME(@bew): Why is the `target` param updated instead of returning a new table?
-local function make_args_absolute(args, parent_insert_position, target)
+---@return LuaSnip.NormalizedNodeRef[] _ The normalized node refs
+local function make_args_absolute(args, parent_insert_position)
+	---@type LuaSnip.NormalizedNodeRef[]
+	local normalized_args = {}
 	for i, arg in ipairs(args) do
 		if type(arg) == "number" then
 			-- the arg is a number, should be interpreted relative to direct
 			-- parent.
 			local t = vim.deepcopy(parent_insert_position)
 			table.insert(t, arg)
-			target[i] = { absolute_insert_position = t }
+			normalized_args[i] = { absolute_insert_position = t }
 		else
 			-- insert node, absolute_indexer, or key itself, node's
 			-- absolute_insert_position may be nil, check for that during
 			-- usage.
-			target[i] = arg
+			normalized_args[i] = arg
 		end
 	end
+	return normalized_args
 end
 
 --- Normarlizes node references
@@ -866,7 +868,7 @@ local function collect_dependents(node, which, static)
 	return tbl_util.set_to_list(dependents_set)
 end
 
----@param args string[]?
+---@param args (string|LuaSnip.SnippetString)[]?
 ---@return string[][]?
 local function str_args(args)
 	return args