In any Rails application you can see which rake tasks are available - either by running
rake -AT (or
rake --all --tasks) to see all tasks, or
rake -T (or
rake --tasks) to see all tasks with descriptions.
However, today I learnt you can also see where a rake task is defined by running
rake -W (or
rake --where). This is useful if a gem is adding a rake task and you want to look at the source.
All of these commands also take an optional pattern to filter the results.