How can you preview the updates that a "Bundle Update" will make?

Question

Sometimes I want to run bundle update but only to see which gems need updating. I don't necessarily want to deal with the issues associated with updating all of them but I want to do a quick check to see what's the state of the art.

Is there a way to simply get Bundler to list the gems that need to be updated together (ideally) with the version I'm currently running and what's the latest and greatest?

Answer 1

There is now a way to do this directly with bundler. You do not need to install any extra gems.

bundle outdated

will return something like this

Outdated gems included in the bundle:
  * acts-as-taggable-on (2.4.1 > 2.3.3)
  * addressable (2.3.4 > 2.3.3)
  * arel (4.0.0 > 3.0.2)
  * better_errors (0.8.0 > 0.7.2)
  * builder (3.2.0 > 3.0.4)
  * capybara (2.1.0 > 2.0.3)
  * chunky_png (1.2.8 > 1.2.7)
  * codemirror-rails (3.12 > 3.02)
  * coffee-rails (4.0.0 > 3.2.2)
  .....