Yes, fiji does show the --js option. However ImageJ2 does not. And while I (now!) understand the technical reasons why the -macro option is not mentioned it makes for a very confusing user experience. Right now, for someone new to IJ it's very difficult to understand the relation between IJ1 and IJ2. The help of the commands not being complete adds to that.
We should document all the options supported by ImageJ itself on the Java side, not just those supported by the launcher itself. It is the ImageJ launcher, after all.
Since ImageJ2 makes these options extensible, one possibility would be for the launcher to invoke net.imagej.Main with --help when it is given --help, so that ImageJ itself can report its own help instructions in addition to those of the launcher.
@PaulVanSchayck writes:
We should document all the options supported by ImageJ itself on the Java side, not just those supported by the launcher itself. It is the ImageJ launcher, after all.
Since ImageJ2 makes these options extensible, one possibility would be for the launcher to invoke
net.imagej.Mainwith--helpwhen it is given--help, so that ImageJ itself can report its own help instructions in addition to those of the launcher.