Ignition coil bench test?

Another method I have used is to drag the Coil negative wire over a long flat-bastard file,that itself is grounded back to the battery;letting it bounce along over the high-points . This method does not require a capacitor. A stream of sparks should issue from the coil tower to anything grounded back to the battery.
Watch out; it is very addictive to watch. It's like playing God; Look what I can do! Zzzzzzzzzz zzzz zzzz zzzzzz z zzzzzz z z z z zzz, oh look it's a mini-welder!