Take it easy with easyb

easyb is a behavior driven development framework for the Java platform. By using a specification based Domain Specific Language, easyb aims to enable executable, yet readable documentation.

Behavior driven development?

Behavior driven development (or BDD) isn't anything new or revolutionary-- it's just an evolutionary offshoot of test driven development, in which the word test is replaced by the word should. Semantics aside, a lot of people have found that the concept of should is a much more natural development driver than the concept of testing. In fact, when you think in terms of behavior (i.e. shoulds) you'll find that writing specifications is easier to do first, which is the intent of test driven development in the first place.


easyb specifications are written in Groovy and run via a Java runner that can be invoked via the command line, Maven 2, or Ant. What's more, easyb supports a few different styles of specifications ranging from RSpec's it to a story based DSL with givens, whens, and thens.

easyb is all about easy.

easyb in action

easyb enables you to verify behavior of normal Java objects, work-flows, etc (basically, anything you write in Java) in a more natural way-- for instance, imagine having a conversation with a customer who wants you to write something to validate zip codes.

"Could you please write something that lets my customers know when they've provided an invalid zip code?"
"Sure! So, given an invalid zip code, this validation service should notify someone that the zip code is incorrect?"
"Right on! Man, you are smart!"

Notice that nowhere in this conversation did anyone say test! Whether or not you write specifications first or afterwards is up to you; however, assuming that you've already written the zip code validator, you could construct a story like so:

  • Given that someone mistypes a zip code
  • And given the zip code validation service is up and running
  • When validate is invoked
  • Then the service should indicate the zip code is invalid

Using the text above, you can then construct an easyb story like so:

      given "an invalid zip code", {
        invalidzipcode = "221o1"

      and "given the zipcodevalidator is initialized", {
        zipvalidate = new ZipCodeValidator()

      when "validate is invoked with the invalid zip code", {
        value = zipvalidate.validate(invalidzipcode)

      then "the validator instance should return false", {
        value.shouldBe false

Is that easy or what? Notice the shouldBe call in the then phrase-- neat, huh?

Requirements, ideas, code-- they're all evolutionary in ways; consequently, you can refactor the scenario above if you find it helpful. For instance, the same scenario can be written more tersely like so:

     given "the zipcodevalidator is initialized", {
       zipvalidate = new ZipCodeValidator()

     then "the validator should return false with invalid zipcodes", {
       zipvalidate.validate("22o1o").shouldBe false

The point being that easyb helps bridge the gap between stakeholders and development by using a language that everyone can understand.

BDD in Java can't get any easier!