mysql

A validation that only rejects self-parenting looks sufficient until a re-parent to your own descendant quietly forms a cycle in the category tree.

TL;DR: Moving A under B seemed fine but created a loop because B was already A's child. The old validation only blocked self-parenting, so the fix now walks up ancestors until it hits a root, a missing parent, or the original category. It uses the standard wrapped-error check and limits the walk to ten levels to handle legacy cycles safely.

Shipping nested categories with zero tests worked until the QA checklist asked for proof: the boot env is a contract, and constraint edges need a real MySQL.

TL;DR: Nested categories were live with no test coverage, and even the health check was broken since it missed required env vars. I patched the env setup and added three MySQL-backed integration tests for tricky deletes that mocks would hide. They run with the integration tag and -p 1 to avoid collisions on the shared test database.

Flipping db-push into db-pull is more than reversing arrows: local backs up first, the dump gets inspected before trusted, backtick rules change over SSH.

TL;DR: Reversing the sync direction puts your local database at risk, so the guard sequence has to flip. The script first backs up local data for rollback, then takes a consistent staging dump and checks size, tables and completion before wiping anything. It avoids SSH backtick issues and strictly compares row counts afterward, preferring a hard failure over a half-finished import.

WP_HOME only fools new pages; old URLs live in the database. WP-CLI search-replace with dry-run and skip-columns=guid is the fix.

TL;DR: Moving a WordPress production dump locally means changing WP_HOME and WP_SITEURL won't fix URLs already stored across posts, meta, and serialized options. Raw SQL REPLACE() is risky because it breaks PHP serialized length prefixes and can overflow column limits. Instead, use wp search-replace with a --dry-run first, always skipping the guid column since those permalinks must never change.