Testing a module before putting it into production

What a test copy genuinely shows

A faithful copy of the store, on a separate address, gives three things no product listing can: the module’s real effect on your data rather than on a demo catalogue, its cost in page generation time, and the freedom to do destructive things — disable, uninstall, start again — with no commercial consequence.

It is also the only place to check interaction with modules already installed. A module behaves differently alone and among fifteen others, and that difference is only observable on a copy of the site as it really is.

The three traps of a staging copy

The domain-locked licence. Many commercial modules check the domain name they run on. On a test address the module may refuse to activate, or activate in a degraded mode. Check first whether the licence covers a test installation: some publishers plan for it explicitly, others don’t.

Production data copied as is. A copy contains real addresses, real email addresses and real orders. Outgoing email must be cut and live payments disabled before the first action, otherwise a test order sends a real message to a real customer.

Environment differences. A module that works in test and not in production nearly always reveals a gap in PHP version, installed extensions or server configuration. A useful staging copy is an identical one, not an approximate one.