Merchlint – Duplicate SKU and GTIN Finder for WooCommerce

Description

Two products with the same SKU throw off stock levels, integrations and every export file your store
produces. Two products with the same GTIN tell a shopping service they are the same item, so one of
them quietly disappears from search. A product with no identifier at all usually drops out of the
feed altogether.

None of this breaks your store, which is why it goes unnoticed for years. Nothing in the WooCommerce
admin points at any of it.

This plugin checks three things and nothing else:

• Two products share the same SKU. Translations of one product are not counted as a duplicate —
  a multilingual store gives every translation the same code on purpose, and reporting that pair
  would be a false alarm. We read the translation groups of Polylang and WPML.
• Product with no GTIN, UPC, EAN or ISBN. Stays quiet in shops that do not use identifiers at
  all: if not one product has the field filled, you get a single sentence saying so instead of a
  list of your entire catalogue. Handmade goods, services and your own production carry no
  manufacturer’s barcode and need none.
• Two products share the same identifier.

What it does not do

It never writes to your catalogue. There is no “Fix it” button, and there will not be one: a
bulk change to product data is not something a report should do on your behalf. Every finding shows
the value that was read, so you can check the claim before you act on it.

It reads no order data, which makes the scan far cheaper than a full audit. The scan still runs
in a single request, so on a very large catalogue it can run into your host’s time limit — the
screen says so when that becomes likely, and the WP-CLI command has no such limit.

Evidence, not adjectives

Every finding shows the field that was read and the value found, with a link straight to the product
in your admin. A rule that could not run says so by name — on WooCommerce older than 9.2 the
identifier field does not exist at all, and the report says that rather than reporting every product
as faulty.

Where the audit engine comes from

The scanning engine is the one behind Merchlint, a full WooCommerce catalogue audit from the same
author. This plugin carries its own copy with its own class names, so both can run side by side.

Technical details