Behavior Driven Development for java - what framework to use? [closed]

Question 1

Behavior Driven Development is just a technique that can be used without any tools. You can just write tests in BDD style - e.g. start test methods with should and introduce some separate feature with this method. When and then sections can be replaced with just comments, e.g.

@Test
public void should_do_something() {
    // given
    Something something = getSomething();

    // when
    something.doSomething();
    // then 
    assertSomething();

    // when
    something.doSomethingElse();
    // then 
    assertSomethingElse();
}

My opinion on the mentioned frameworks:

The problem with JBehave is that tests look like a complex spaceship. On the other hand it has pretty output for your specifications.
spock is really cool. Compact syntax, pretty output, a lot of features, written with the powerful groovy language, which means the possibility of usage in conjunction with geb. BUT it is groovy and it can be very important for someone.
scalatest (written with scala) and easyb (written with groovy) both have the same disadvantage as spock. The "... should ..." and "Given...Then" notation. Specifications are in .story files, and the step implementations are in Java classes. This approach work very well as a collaboration and communication tool to define the specs, but would usually be too much overhead for low-level coding.

I also think that the most successful BDD frameworks for Java are those that are not written in Java, since the Java language has no such flexibility for DSL (Domain Specific Language) creation that Groovy or Scala has.

Question 2

As the author of JGiven I have to disagree with sody that Java has not enough flexibility for DSL creation. In JGiven, BDD tests looks as follows:

@Test
public void users_can_login {
    given()
       .a_registered_user()
       .and().the_login_page_is_shown();

    when()
       .the_user_enters_correct_credentials()
       .and().the_login_button_is_pressed();

    then()
       .the_welcome_page_is_shown();
}

JGiven is used together with JUnit or TestNg and you write your tests in plain Java.

Question 3

Unless your product owner/qa/customer need to be able to read the tests, use Spock. It is very simple tool, but improves readability of tests. Thanks to it's powerful features you don't need Mockito, Hamcrest nor AssertJ. And it has superb parametrized tests. In fact, it is "just" a better JUnit - a general tool for automated execution of simple tasks, be it unit tests, integration tests or acceptance tests.

Fearing Groovy? Why? It is very similar to java. The more you learn it, the more expressive and shorter your code is. Your tests will be shorter and more readable. Groovy is gateway drug to the better side of JVM.

Don't like dynamic languages? Well, it is tests, and tests are run by CI server after every commit, right? If your code breaks, you will know it after few minutes. Don't have CI server or not running tests regularly? Then don't bother with choosing a test framework and go fix your process. Broken tests are useless and if you don't run the tests regularly, they will break soon.

Go with JBehave/Cucumber if you need it; Otherwise, use Spock.

Question 4

Another alternative would be Spectrum - see https://github.com/greghaskins/spectrum

Spectrum supports the RSpec/Mocha syntax and in its next release will also support Gherkin syntax, along with JUnit rule integration (so it interoperates with Mockito, Spring etc via the @Rule and @ClassRule members).

Full disclosure - I'm a contributor to this OS project

Example:

@RunWith(Spectrum.class)
public class TestSomething {{
    Supplier<Something> freshTestObject = let(Something::new);

    describe("The component", () -> {
        it("is tested by specs", () -> {
            // the "let` above gives us a new instance of the object
            // in each spec
            freshTestObject.get().doSomething();

            // using your favourite assertion framework
            assertThat(something.get().getSomething()).isEqualTo(42);
        });
    });
}}

Spectrum outputs a hierarchical test result in your JUnit console. The strength of it is in mixing the Java implementation of the spec execution in with the spec definition - this can be more direct than frameworks that rely on feature files and glue code to parse them, especially if there's a need to pass results from one step of the test to another.

Spectrum aims to be polyglot, so should seem familiar to users of several existing frameworks.

Question 5

Give Ginkgo4j a go. It uses Java 8's lamda's to mirror the approach used by Ruby's RSpec and Go's Ginkgo.

This library allows you to build expressive, content-rich tests.

```

package com.github.paulcwarren.ginkgo4j.examples;

import static com.github.paulcwarren.ginkgo4j.Ginkgo4jDSL.*;
import static org.hamcrest.CoreMatchers.is;
import static org.hamcrest.MatcherAssert.assertThat;

import org.junit.runner.RunWith;

import com.github.paulcwarren.ginkgo4j.Ginkgo4jRunner;

@RunWith(Ginkgo4jRunner.class)
public class BookTests {
    private Book longBook;
    private Book shortBook;
    {
        Describe("Book", () -> {
            BeforeEach(() -> {
                longBook = new Book("Les Miserables", "Victor Hugo", 1488);
                shortBook = new Book("Fox In Socks", "Dr. Seuss", 24);
       });

       Context("Categorizing book length", () -> {
           Context("With more than 300 pages", () -> {
               It("should be a novel", () -> {
                   assertThat(longBook.categoryByLength(), is("NOVEL"));
               });
           });

           Context("With fewer than 300 pages", () -> {
               It("should be a short story", () -> {
                   assertThat(shortBook.categoryByLength(), is("NOVELLA"));
              });
           });
       });
       });
     }
}

```

Also supports Spring.

(Full disclosure. I am the author of this library).

Question 6

Nice discussion! I did not know JGiven, but I will have a look in it.

In addition, I'm the author of COLA Tests, a new framework that supports full gherkin syntax (precisely the same as Cucumber), it's really easy to setup, specially when compared with JBehave and does not require JUnit runner.

Basically just use whatever libs you are already used to!

Here is an example Spring Controller Test (stories can be loaded from a file):

@RunWith(SpringJUnit4ClassRunner.class)
@WebAppConfiguration
@ContextConfiguration(classes = { WebAppContext.class })
public class HelloWorldControllerTest extends BaseColaTest {

    private final String stories =
        "Feature: Introduce REST endpoint\n"
            + "Scenario: Should say hello\n"
            + "Given a web endpoint\n"
            + "When hit by a get request\n"
            + "Then the HTTP status will be OK\n"
            + "And the body will say hello world";

    @Resource
    private WebApplicationContext webApplicationContext;
    private MockMvc mockMvc;
    private ResultActions result;

    @Given("a web endpoint")
    public void given() {
        mockMvc = MockMvcBuilders.webAppContextSetup(webApplicationContext).build();
    }

    @When("hit by a get request")
    public void when() throws Exception {
        result = mockMvc.perform(get("/helloWorld"));
    }

    @Then("the HTTP status will be OK")
    public void thenOk() throws Exception {
        result.andExpect(status().isOk());
    }

    @Then("the body will say hello world")
    public void thenHello() throws Exception {
        result.andExpect(content().string("Hello World!"));
    }
}