Testing Grails services with easyb

The Grails easyb plugin has a nifty feature for obtaining instances of service classes. Simply call inject along with the name of your service (i.e. “dateService”) and it’ll auto-magically be available as a variable.

Before you can use this feature, you first must install the easyb plugin like so:

%>grails install-plugin easyb

You can place your .story files (or .specification ones) in any of the sub-directories found in the test directory. For example, if I have a service dubbed DateFormatService that I wish to verify in an easyb story, I can create a story dubbed DateProcessing.story in my test/integration directory.

The story is simple:

scenario "string dates should be converted correctly", {
  given "a date service object", {
    inject "dateFormatService"
  }

  and "and date string", {
    param = "10/07/2010"
  }

  then "the service should return date objects in various formats", {
    date = dateFormatService.day01(param)
    date.time.shouldBe 1285905600000 //i.e. 10/01/2010

    date2 = dateFormatService.day28(param)
    date2.time.shouldBe 1288238400000 //i.e. 10/28/2010
  }
}

Note, to validate java.util.Date instances, I simply convert them into longs and ensure the epoch time is correct. And as you can see from the code above, the call to inject "dateFormatService" makes a variable dubbed dateFormatService available.

By calling inject the entire dependency graph is formally injected too — that is, if service class Foo has a reference to service Bar, then when Foo is injected into an easyb story, Bar will have been pre-injected into Foo (which is distinctly different than calling new Bar().

Invoking the story from the command line is easy too:

%>grails test-app :easyb

This command runs any easyb file found — you can also run individual stories and directories of stories.

For more information on the easyb Grails plugin, check out the Grails plugin page — if you have questions, join the easyb mailing list, baby!