Yarn ignores invalid command line arguments

[mprobst]

Do you want to request a feature or report a bug?

A bug.

What is the current behavior?

$ yarn install --parsing-command-line-arguments-is-hard
yarn install v0.19.1
[1/4] Resolving packages...
[2/4] Fetching packages...
[3/4] Linking dependencies...
[4/4] Building fresh packages...
[...]
Done in 12.71s.

If the current behavior is a bug, please provide the steps to reproduce.

yarn silently ignores unknown command line arguments. That's a usability problem, i.e. when users mistype an argument, the command silently proceeds but then fails to behave as expected, leaving a puzzled user. Combined with potentially dangerous arguments, this can be a bigger problem. Imagine installing an untrusted package that you'd like to inspect for security reasons, but misstyping --ignore-scripts.

What is the expected behavior?

$ yarn install --fried-chicken
yarn install v0.19.1
error Unknown argument "--fried-chicken".

Please mention your node.js, yarn and operating system version.

Node v5.3.0, Ubuntu.

[BYK]

I don't think this is a bug and it is a very good enhancement in terms of safety so marking as high-priority.

[joaoptpsa]

Me and a team of 2 others will attempt to fix this issue

[joaoptpsa]

So basically this issue is due to a issue in commander.js dependency, i created a PR for commander.js tj/commander.js#730 that would fix this, should it get accepted

[shadowspawn]

This is likely fixed from Commander v5: tj/commander.js#561

Update, Yarn 2 is using Clipanion: #4225 (comment)