The most popular methods are to use a switched current source alternating from,sink to source at safe levels and looking at the response time for excessive capacitance which can signal an "almost short "in CMOS or a low voltage swing.
Backdriving junction points incircuit are often done by ATE but this won't detect leakage, just transfer function. Guard circuits are often used with outer coax, in low frequency current sources to null or reduce the effect of cable capacitance.