Exercises

1.  Add a test for the email downcasing from Listing 6.23, as shown in Listing 6.31. By commenting out the before_save line, verify that Listing 6.31 tests the right thing.
2.  By running the test suite, verify that the before_save callback can be written as shown in Listing 6.32.
3.  Read through the Rails API entry for ActiveRecord::Base to get a sense of its capabilities.
4.  Study the entry in the Rails API for the validates method to learn more about its capabilities and options.
5.  Spend a couple of hours playing with Rubular.