There are a number of rake tools in a rails project a lot of people just don't know about. Here are a few of them.

Routes

rake routes

Every one knows about rake routes right? Well you can limit the results with a couple of methods. First limit by controllers:

% rake routes CONTROLLER=posts

rake routes with grep

But I usually resort to just piping to grep. Why? Because the 'term' can be a controller, action, path/url name, even an HTTP verb like 'DELETE'. I find this very effective when I am looking through someone elses work, finding a rarely used path, or jogging my memory on a complex url helper name.

% rake routes | grep term

Database

rake db:test:prepare

The following simply prepares the database for your tests. If you have test failing after you changed the database, and they are not failing in development, this is usually the task that needs to be run.

% rake db:test:prepare

rake db:migrate:status

Want a nice list of all the migrations with an up/down for which ones have and have not been run? This is nice after a pull and when your are running migrations up and down before a 'larger than it should be commit.' (I never do that...) None the less, it gives a nice high level persepective.

% rake db:migrate:status

database: project_development

 Status   Migration ID    Migration Name
--------------------------------------------------
   up     20111210105537  Create organizations
   up     20111213020956  Create positions
   up     20111213162045  Remove role from position
   up     20111213165355  Create roles
   down   20111214031957  Add permissions to roles

rake db:reset

I was afraid of this one for a long time. It was silly in hind site. All rake db:reset does is truncate all of the tables, re-run all of your migrations, and run rake db:seeds. If you want to clean out some crappy data in your development database and get it back to your starting poing (You use your seeds.rb file right?) then this is the way to go. It is great for experimenting. Go ahead try something new, risky, or plain stupid and you can get right back to where yoy were. No fuss.

% rake db:reset

Statistics

rake stats

Besides being interesting to look at, I love to watch the 'Code to Test Ratio:' on the bottom. If your ratio is about 1:1 you are probably only testing the 'happy path', which is better than nothing, but in reality there are a lot more things that can go wrong than go right.... I have found (thus far) that a ratio of about 1:2 or 1:3 is usually where I perfer to sit. I have the highest velocity (forward momentum) on the project here. I loose a bit of speed if I go above 3, because I am writing too many tests, but that is far preferrable (and sometimes neccessary depending on the complexity of the code) than the alternative. If I drop below, I greatly loose speed because I have have to manually test things and refactoring becomes painful.

% rake stats 
+----------------------+-------+-------+---------+---------+-----+-------+
| Name                 | Lines |   LOC | Classes | Methods | M/C | LOC/M |
+----------------------+-------+-------+---------+---------+-----+-------+
| Controllers          |   132 |   103 |       8 |      13 |   1 |     5 |
| Helpers              |    27 |    20 |       0 |       2 |   0 |     8 |
| Models               |   431 |   275 |      13 |      25 |   1 |     9 |
| Libraries            |     0 |     0 |       0 |       0 |   0 |     0 |
| Integration tests    |    34 |    24 |       1 |       1 |   1 |    22 |
| Functional tests     |   378 |   320 |       7 |       8 |   1 |    38 |
| Unit tests           |   533 |   417 |      19 |      10 |   0 |    39 |
+----------------------+-------+-------+---------+---------+-----+-------+
| Total                |  1535 |  1159 |      48 |      59 |   1 |    17 |
+----------------------+-------+-------+---------+---------+-----+-------+
  Code LOC: 398     Test LOC: 761     Code to Test Ratio: 1:1.9

Rake

rake -T

In conclusion, the last task to know about is: rake -T. You can list all of the described tasks with just the -T, but you can also add a term on to the end and search though the available tasks.

% rake -T
rake about                         # List versions of all Rails frameworks and the environment
rake assets:clean                  # Remove compiled assets
rake assets:precompile             # Compile all the assets named in config.assets.precompile
rake auth:used_privileges          # Lists all privileges used in controllers, views, models
...
% rake -T vlad
rake vlad:app:configure            # Write and symlink unicorn config file.
rake vlad:app:start                # Alias for vlad:start_app
rake vlad:app:symlink              # Symlink unicorn config file.
...

I hope this brief look at the rake tools available in a Rails project has been helpful, and encourages you to find other helpful tasks.