yarn silently deletes packages with .git directory in node_modules on add

[pdxjohnny]

BUG

What is the current behavior?

/me is working on dependency of $package checked out to $PWD/node_modules/$dep
/me $ yarn add chart.js
/yarn rm -rf $PWD/node_modules/$dep
/yarn oh gee just deleted everything you hadn't pushed yet bummer huh

What is the expected behavior?

/me is working on dependency of $package checked out to $PWD/node_modules/$dep
/me $ yarn add chart.js
/yarn rm -rf $PWD/node_modules/$dep -i <- hey I'm about to nuke all your work. Should I do that?

[Kocal]

You should not update code in node_modules in this way.
If you want to, use yarn link

[pdxjohnny]

Would there be receptiveness to a PR making yarn warn before deletion, giving user the option to back out of an add and telling them to link if their changes are intentional.