feat: add testing utilities including context, mock functions, and snapshot handling

packages/lua_test/seed/scripts/string_utils.lua

@@ -0,0 +1,43 @@
+-- String utilities for testing
+-- Provides trim, split, startsWith, endsWith functions
+
+---@class StringUtils
+local M = {}
+
+---Trim whitespace from both ends of a string
+---@param s string String to trim
+---@return string Trimmed string
+function M.trim(s)
+  return s:match("^%s*(.-)%s*$")
+end
+
+---Split a string by delimiter
+---@param s string String to split
+---@param delimiter? string Delimiter pattern (default whitespace)
+---@return string[] Array of parts
+function M.split(s, delimiter)
+  delimiter = delimiter or "%s"
+  local result = {}
+  for match in (s .. delimiter):gmatch("(.-)" .. delimiter) do
+    result[#result + 1] = match
+  end
+  return result
+end
+
+---Check if string starts with prefix
+---@param s string String to check
+---@param prefix string Prefix to look for
+---@return boolean True if s starts with prefix
+function M.startsWith(s, prefix)
+  return s:sub(1, #prefix) == prefix
+end
+
+---Check if string ends with suffix
+---@param s string String to check
+---@param suffix string Suffix to look for
+---@return boolean True if s ends with suffix
+function M.endsWith(s, suffix)
+  return suffix == "" or s:sub(-#suffix) == suffix
+end
+
+return M