1335620 - Don't assume "uninstall" means "install"

Status: UNCONFIRMED

(Firefox Build System :: Mach Core, enhancement)

Description

[Maxime Buquet]

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:53.0) Gecko/20100101 Firefox/53.0
Build ID: 20170122162409

Steps to reproduce:

`./mach uninstall`


Actual results:

"We're assuming the 'uninstall' command is 'install' and we're executing it for you." happened.


Expected results:

An error telling me uninstall doesn't exist, or actually uninstalling files.

I understand "guessing" feature can be handy, but there are probably commands you don't want to run this way.

Comment 1

[Wes Kocher (:KWierso) (Not reading bugmail; email directly if needed)]

Attachment: Bug 1335620 - Don't assume "uninstall" means "install"

`mach install` is a command to install the package onto the device. People might assume that `mach uninstall` exists and does the opposite of `mach install`, but it doesn't.

When the user runs `mach uninstall`, mach helpfully looks for suggested similar commands, and picks `install` as the best option and immediately proceeds to run it.

This patch explicitly prevents mach from looking for suggestions when the entered command is `uninstall`.

Review commit: https://reviewboard.mozilla.org/r/180666/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/180666/

Comment 2

[Wes Kocher (:KWierso) (Not reading bugmail; email directly if needed)]

This patch explicitly prevents "uninstall" from looking up suggested alternatives. Maybe this should be a list of banned unknown commands?

If you accidentally type `mach uinstall`, it'll still suggest and auto-run `install`, which may or may not be desirable.
Thoughts?

Comment 4

[Gregory Szorc [:gps]]

Comment on attachment 8909063 [details]
Bug 1335620 - Don't assume "uninstall" means "install"

https://reviewboard.mozilla.org/r/180666/#review186162

It is a layering violation for mach's dispatch layer to know about the existence of any custom commands. This code is generic and is used by projects like Servo as well. We can't make assumptions about desired behavior.

The proper solution is to somehow declare which commands cannot match other similarly named commands. This could be an argument to @Command decorators. This could be a data structure that is somehow loaded into the mach driver (probably in mach_bootstrap.py). Either way, specific command names shouldn't be added to python/mach/.