ModFinder.java

import net.fabricmc.loader.api.FabricLoader;
import net.fabricmc.loader.api.ModContainer;

import java.net.URISyntaxException;
import java.nio.file.Path;
import java.util.HashMap;
import java.util.Map;
import java.util.Optional;

public class ModFinder {
	private final Map<Path, ModContainer> modsByJarPath = new HashMap<>();

	public Optional<ModContainer> find(Class<?> clazz) {
		try {
			Path path = Path.of(clazz.getProtectionDomain().getCodeSource().getLocation().toURI());
			if (path.getFileSystem().getPathMatcher("glob:**/build/classes/*/main").matches(path))
				path = path.resolveSibling("../../resources/main").normalize();
			return Optional.ofNullable(modsByJarPath.computeIfAbsent(path, key -> {
				for (ModContainer mod : FabricLoader.getInstance().getAllMods()) {
					if (mod.getOrigin().getPaths().contains(key))
						return mod;
				}
				return null;
			}));
		} catch (URISyntaxException e) {
			return Optional.empty();
		}
	}
}