`list`: display purchaser Apple Account

[ncrash]

As of right now, list results look like this:

$ mas list
441258766 Magnet (1.9.13)
992076693 MindNode (2.4.3)
443987910 1Password (6.3.5)
489094439 iTeleport (6.1.8)

I think list results should display the purchased account of an app as well, like this:

$ mas list
441258766 daekwon.kang@gmail.com Magnet (1.9.13)
992076693 daekwon.kang@gmail.com MindNode (2.4.3)
443987910 daekwon.kang+ikr@gmail.com 1Password (6.3.5)
489094439 daekwon.kang+ikr@gmail.com iTeleport (6.1.8)

[grempe]

This would be very helpful. For example, other machines in my household were shared at one point and have apps installed from more than one account which makes installing upgrades painful since it requires multiple logins. This would be a great way to identify those apps, uninstall them, and install from the account of the single current user of the machine. I know of no way to identify these apps using the full MAS.

[rgoldberg]

If we support json output (#190), then users could configure output however they want by piping to other commands.

We could allow users to configure the normal, non-JSON output on a per-field basis, or we could modify the default output, and/or provide different output levels like --verbose, --all-fields, etc.

I would argue for outputting JSON via --json, and maybe for adding a --fields <comma-separated list of field names> for configuring the non-JSON (and possibly filtering JSON) output.

The main issue is that list sources its data from CKSoftwareMap.shared().allProducts() from the private CommereKit. The Swift property names for the fields are most likely different than the Apple web endpoint JSON property names for the same data. Either we'd have to use different field names for --json & for fields, or we'd have to maintain a map between the two, or we'd have to lookup data & its correct field names by querying the Apple web endpoint for the correct data instead of using the data from CommereKit.

What do you prefer?

I prefer keeping a consistent field & JSON interface to the user, and I prefer avoiding unnecessary web calls, so I prefer maintaining a map between field names, if different.