I've read a few of your posts, but to be honest - i'm very bad at what you're asking.
There is a feeling that you have specific knowledge in a particular area (с#?) , but are completely unfamiliar with xml for 7dtd.
Hi n2n1. How do you quickly and isolatedly test a C# method or class you just wrote ?
What is the effect in your understanding here? many things can be called effects!
Well....create a new (own) block/item and use your function in the block or item, with the appropriate rules...
Yes, sounds corny.
for example, if it is a block - you can declare this
class in a block in the same way as it is done in other blocks. Further - control should be transferred to your functions....as i understand...if what you wrote is a new class.
You need more specifics.
////I just coded a cool effect in 7D (actually just spawning a block at a given location), how do you test it ?
////
Okay, what commands (from xml) control your custom spawn now? (it's rhetoric)
(I just don't understand how you could write this without imagining how it would work)
Who will deal with the spawning of this block? Another block? item? entity? world generator?
You want to spawn the block at coordinates x,y,z? on a particular type of biome? in prefab?
////- Can I define a game command that would execute my effect ?
////
What are you talking about here? xml, dll, console ?
Regarding c# - i can't help, unfortunately.
If it is xml, then you can take for example some of the existing commands to do something like that...but i can't advise because the purpose of your C# code is shrouded in mystery.
PS:
If you have knowledge with c# coding maybe you could help me in this matter
https://7daystodie.com/forums/showthread.php?139016-Question-about-editing-class-methods-in-dnSpy