A formation testing method can include interconnecting multiple pressure sensors and multiple perforating guns in a perforating string, the pressure sensors being longitudinally spaced apart along the perforating string, firing the perforating guns and the pressure sensors measuring pressure variations in a wellbore after firing the perforating guns. Another formation testing method can include interconnecting multiple pressure sensors and multiple perforating guns in a perforating string, firing the perforating guns, thereby perforating a wellbore at multiple formation intervals, each of the pressure sensors being positioned proximate a corresponding one of the formation intervals, and each pressure sensor measuring pressure variations in the wellbore proximate the corresponding interval after firing the perforating guns.