Can bundler show me which gems in Gemfile have newer versions (eg. dry-run of bundle update)

Question

Is there a way to run bundle update in pretend mode, similar to the -p (pretend) flag for Rails generators or cap's -n (dry-run) flag?

I'm imagining something like:

$> bundle update -p
Fetching source index for http://rubygems.org/
The following gems have updated versions:
...
list of gems
...

Answer 1

Bundler 1.1 introduced a new 'outdated' feature, which is exactly what I was looking for. Pat Shaughnessy has a great write-up on the new features. In his words, bundle outdated:

displays the gems it would download and install, but without actually doing it. This gives me the freedom to inspect the list and update just the gems I would like to.

This should make it a snap to see what gems are due for an update without actually modifying your source and local gems. Thanks Bundler!

Answer 2

$ bundle update $ git diff Gemfile.lock $ git checkout Gemfile.lock 

Answer 3

I was looking specifically for how to only show the outdated gems that are in my gemfile. Looks like this does it: bundle outdated --only-explicit

That will 'Only list gems specified in your Gemfile, not their dependencies'

Source: https://bundler.io/man/bundle-outdated.1.html

Hopefully this is helpful for someone else.