March 27, 2012 • Text Post

Cucumber-JVM 1.0.0

Today I am very excited to announce Cucumber-JVM 1.0.0.

Cucumber-JVM is a pure Java implementation of Cucumber, with native support for the most popular JVM languages: Java, Scala, Groovy, Clojure, Rhino, Jython and JRuby. Cucumber-JVM is the successor of Cuke4Duke, which was the Ruby implementation of Cucumber, running on JRuby. Cuke4Duke was a pain to use - it was hard to install and both slow and difficult to run.

Cucumber-JVM on the other hand is easy to install, and it’s fast and easy to run (thanks to its JUnit integration).

I will be giving an introduction to Cucumber-JVM at CukeUp! on April 4, and I am also working on documentation, but for now let me give you a quick glance of what you can do with it. We are going to create the following files:

.
|-- build.xml (Optional)
|-- pom.xml (Optional)
`-- src
    |-- main
    |   `-- java
    |       `-- cucumber
    |           `-- examples
    |               `-- java
    |                   `-- helloworld
    |                       `-- Hello.java
    `-- test
        |-- java
        |   `-- cucumber
        |       `-- examples
        |           `-- java
        |               `-- helloworld
        |                   |-- HelloStepdefs.java
        |                   `-- RunCukesTest.java
        `-- resources
            `-- cucumber
                `-- examples
                    `-- java
                        `-- helloworld
                            `-- helloworld.feature

Start by creating helloworld.feature:

Feature: Hello World
  Scenario: Say hello
    Given I have a hello app with "Howdy"
    When I ask it to say hi
    Then it should answer with "Howdy World"

Now, create a pom.xml if you want to use Maven or a build.xml if you want to use Ant. This is all you need to download Cucumber-JVM and run your features.

Next, create RunCukesTest.java which is used to run features from JUnit:

package cucumber.examples.java.helloworld;

import cucumber.junit.Cucumber;
import org.junit.runner.RunWith;

@RunWith(Cucumber.class)
@Cucumber.Options(format = {"pretty", "html:target/cucumber"})
public class RunCukesTest {
}

We are passing some options to Cucumber, telling it to generate a HTML report as well.

When you run ant download runcukes or mvn test you will see all of your steps showing up as undefined. Cucumber-JVM will print some snippets to get you started. Let’s add those snippets to HelloStepdefs.java and fill in the blanks:

package cucumber.examples.java.helloworld;

import cucumber.annotation.en.Given;
import cucumber.annotation.en.Then;
import cucumber.annotation.en.When;

import static org.junit.Assert.assertEquals;

public class HelloStepdefs {
    private Hello hello;
    private String hi;

    @Given("^I have a hello app with \"([^\"]*)\"$")
    public void I_have_a_hello_app_with(String greeting) {
        hello = new Hello(greeting);
    }

    @When("^I ask it to say hi$")
    public void I_ask_it_to_say_hi() {
        hi = hello.sayHi();
    }

    @Then("^it should answer with \"([^\"]*)\"$")
    public void it_should_answer_with(String expectedHi) {
        assertEquals(expectedHi, hi);
    }
}

Finally we need an implementation of our Hello World system in Hello.java:

package cucumber.examples.java.helloworld;

public class Hello {
    private final String greeting;

    public Hello(String greeting) {
        this.greeting = greeting;
    }

    public String sayHi() {
        return greeting + " World";
    }
}

Run Ant or Maven again, and all is green. If you would rather do all of this in Scala, Groovy, Clojure, Rhino, Jython, JRuby - or even Ioke - that’s easy too. You will find more examples here.

Some other features of Cucumber-JVM:

• Multiple output formats: HTML, JSON, JUnit and more.
• DI support: PicoContainer, Guice, Spring, Weld and OpenEJB.
• Automatic conversion of step definition arguments.
• I18n support for over 40 spoken languages
• Grails and Play support on its way.
• IntelliJ support is on the way.

Take it for a spin and let us know what you think!