To test an ignition coil you need a spark tester with a adjustable gap.
The coil should jumpa a spark for 3/8 in or more in atmosphere.
But there can be other issues that cause no spark if you check with the coil connected to the engine.
To be really sure you have to test with a coil tester at bench.
You can Ohm test with a VOM but as I said in an other thread recently the prime winding of an ignition coil has a very low Ohm value, about 0,5-2,0 Ohm.
You are not able to check and see if the prime side is good or has a short cut in the winding with a VOM, a VOM tests resistance with a low voltage about 4-9 Volts depending on brand.
The ignition system put out 200+Volts to the coil prime winding.
With bad insulation between the windings in the coil the spark can jump inside it when you load it with high voltage.
