In a large application, running all the tests at once using rake spec can make it difficult to check the output of the test you're working on. Especially if you have many failing or pending tests. Run a single test by running rspec:
rspec spec/models/account.rb
You can be even more specific and run a specific example from a test file. For example, given the following tests:
11: describe "#deposit!" do
12: it "adds value to the balance" do
13: expect{account.deposit!(10)}.to change{account.balance}.by(10)
14: end
15: it "returns the balance" do
16: account.deposit!(10).should == account.balance
17: end
18: endrspec account_spect.rb:15 will only run the test it "returns the balance"
Running a specfic example file or test helps you focus, but don't forget to run the entire test suite with rake spec before making any commits. While the test you're might be passing, it's very possible your changes might have broken another test. Better to get that feedback immediately, rather than later.
When you run any rails application (the webserver, tests or rake tasks) ouput from the running code is saved to a log file. There are log files per environment: log/development.log, log/test.log and log/production.log
Take a moment to open up one of these log files in your editor and take a look at its contents. To keep an eye on what's new in your log files, use the *nix tool tail. Try running the following on your terminal:
tail -f log/test.log
Now run a test. Curious what -f means? Check the man page for the tail utility: man tail