Add io.write_to_file() helper. Relates to lord-server#925. Needs for …

…lord-server#1502

.luacheckrc

@@ -42,7 +42,7 @@ read_globals      = {
 
 	io = { fields = {
 		-- our Core/helpers:
-		"file_exists",
+		"file_exists", "write_to_file"
 	} },
 
 	os = { fields = {

mods/lord/Core/helpers/src/lua_ext/io.lua

@@ -10,3 +10,34 @@ function io.file_exists(name)
 
 	return false
 end
+
+--- Writes `content` into file by path `filepath`
+--- Returns `true` if success or `false, error_code, error_message`
+---
+--- @param filepath string
+--- @param content  string
+--- @param mode     string default: `"w"`
+---
+--- @return file|nil,nil|number,nil|string
+---
+--- @overload fun(filepath:string, content:string):boolean,nil|number,nil|string
+--- @overload fun(filepath:string, content:string):boolean,nil|number,nil|string
+function io.write_to_file(filepath, content, mode)
+	mode = mode or "w"
+
+	local file, error_message, error_code = io.open(filepath, mode)
+	if not file then
+		return false, error_code, error_message
+	end
+
+	local success
+	success, error_message, error_code = file:write(content)
+	if not success then
+		file:close()
+		return false, (error_code or -1), (error_message or "unknown reason")
+	end
+
+	file:close()
+
+	return true
+end