How to remove unused dependencies from composer?

Question

I installed a package with composer, and it installed many other packages as dependencies.

Now I uninstalled the main package with composer remove packageautho

Answer 1

The right way to do this is:

composer remove jenssegers/mongodb --update-with-dependencies

I must admit the flag here is not quite obvious as to what it will do.

Update

composer remove jenssegers/mongodb

As of v1.0.0-beta2 --update-with-dependencies is the default and is no longer required.