FR: Add REPL package mode command

[marius311]

I think you can hook into / modify the package mode REPL, so it would be pretty awesome if I could put TestEnv in my startup.jl then have:

pkg> activate --test

or

pkg> activate --test Foo

[oxinabox]

that would be cool.
No idea if it is possible.

[marius311]

I did a tiny bit of digging, for an example how to add a new package command, see this

However, to add an option (--test) to an existing command (activate), would require overwriting the existing registered command here. Definitely possible, if slightly hacky. Maybe I'll hack on it more if I find the time, but in the meantime maybe this is useful to someone.

[oxinabox]

maybe easier is to add a new pkgmode command ] activate-test?