Installation Testing
Installation testing verifies that software installs, upgrades, and uninstalls correctly across the environments it's meant to support — checking for missing dependencies, permission issues, correct default configuration, and clean removal without leftover files or broken system state.
For consumer software this means testing the actual installer across supported operating systems and versions; for backend systems it might mean testing deployment scripts, container builds, or infrastructure provisioning. Either way, the goal is the same: confirm the "getting started" step doesn't fail before a user or system ever reaches the actual product.
Upgrade paths deserve particular attention — installing fresh is usually well tested, but upgrading from an older version while preserving existing data and configuration is a much less forgiving scenario, and a common source of production incidents when skipped.
