legacy code

Legacy Bash is brittle; this post delivers a terminal-ready, test-first workflow to refactor it safely with AI: pair ShellCheck, shfmt, Bats, jq, and ripgrep; baseline and trace behavior; apply modern idioms (set -Eeuo pipefail, traps, mktemp, jq); auto-curate prompt context; replace fragile parsing; and iterate under tests—producing cleaner, faster, maintainable scripts in about an hour.

A practical, test-first guide to using AI to safely refactor legacy Bash: install shellcheck/shfmt/bats/jq/git, add guardrails (set -Eeu -o pipefail, traps), freeze behavior with bats tests, fix lint/format issues, then prompt an LLM for minimal, portable diffs (arrays, mapfile, find -print0, mktemp, quoting), verify via tests and CI, with examples and a mini-case to boost reliability without changing intent.