If there is nothing in the specifications on testing, only the specified standards would apply unless you modify the contract.
In the U.S., UL 891 would typically apply for low voltage switchboards. If the specs require switchgear construction per ANSI standards, ANSI C37.20.1 and UL 1558 would apply. You must read the specs very carefully to determine which standards apply.
Any of these standards will require insulation resistance (megger) testing of the bus and control wiring, AC insulation strength (hipot) test, ground fault system test if applicable, operation of all circuit breakers and switches and functional testing of control schemes and interlocks.
NETA testing is much more comprehensive but would apply only if it is required by the specifications. NETA tests are normally intended to be performed after installation rather that at the factory.