How do you check for clogged fuel lines?

How do you check for clogged fuel lines?
Never seen a clogged fuel line unless it was kinked or crushed. Do a visual inspection for damage then replace the fuel filter and do a fuel pressure test.

Fuel lines can get clogged if foreign objects (rags etc.) have been dropped into the fuel tank.
Disconnect both ends and blow through.
It is not sufficient to diconnect the engine side and see if the fuel runs out. Most modern cars with fuel injection have a tank pump, which would stop the natural flow under gravity.