Instinct is a Behaviour Driven Development (BDD) framework for Java. Inspired by RSpec, Instinct provides:

The sections below illustrate using Instinct for the examples from Using Testing Frameworks with Groovy.

The Stack Example

Here is how you might use Instinct to test the Stack Example:

// require(url:'http://code.google.com/p/instinct', jar:'instinct-0.1.5.jar')
// require(url:'http://geekscape.org/static/boost.html', jar:'boost-982.jar')
// require(groupId:'org.jmock', artifactId:'jmock', version:'2.2.0')
import com.googlecode.instinct.marker.annotate.*
import com.googlecode.instinct.runner.TextRunner

class AlmostEmptyFixedStackContext {
    private stack

    @BeforeSpecification
    void initially() {
        stack = new FixedStack()
        stack.push 'anything'
        assert !stack.isEmpty()
    }

    @Specification
    void shouldRemainNotEmptyAfterPeek() {
        stack.peek()
        assert !stack.isEmpty()
    }

    @Specification
    void shouldBecomeEmptyAfterPop() {
        stack.pop()
        assert stack.isEmpty()
    }
}

class AlmostFullFixedStackContext {
    private stack

    @BeforeSpecification
    void initially() {
        stack = new FixedStack()
        (1..<FixedStack.MAXSIZE).each{ x -> stack.push x }
        assert !stack.isFull()
    }

    @Specification
    void shouldBecomeFullAfterPush() {
        stack.push 'anything'
        assert stack.isFull()
    }
}

class EmptyFixedStackContext extends GroovyTestCase {
    private stack = new FixedStack()

    @BeforeSpecification
    void preConditions() {
        assert stack.isEmpty()
    }

    @Specification
    void shouldNoLongerBeEmptyAfterPush() {
        stack.push 'anything'
        assert !stack.isEmpty()
    }

    @Specification
    void shouldComplainWhenSentPeek() {
        shouldFail(StackUnderflowException) {
            stack.peek()
        }
    }

    @Specification
    void shouldComplainWhenSentPop() {
        shouldFail(StackUnderflowException) {
            stack.pop()
        }
    }
}

class FullFixedStackContext extends GroovyTestCase {
    private stack

    @BeforeSpecification
    void initially() {
        stack = new FixedStack()
        (1..FixedStack.MAXSIZE).each{ x -> stack.push x }
        assert stack.isFull()
    }

    @Specification
    void shouldRemainFullAfterPeek() {
        stack.peek()
        assert stack.isFull()
    }

    @Specification
    void shouldNoLongerBeFullAfterPop() {
        stack.pop()
        assert !stack.isFull()
    }

    @Specification
    void shouldComplainOnPush() {
        shouldFail(StackOverflowException) {
            stack.push 'anything'
        }
    }
}

class NonEmptyFixedStackContext {
    private stack

    @BeforeSpecification
    void setUp() {
        stack = new FixedStack()
        ('a'..'c').each{ x -> stack.push x }
        assert !stack.isEmpty()
    }

    @Specification
    void shouldAddToTheTopWhenSentPush() {
        stack.push 'd'
        assert stack.peek() == 'd'
    }

    @Specification
    void shouldBeUnchangedWhenSentPushThenPop() {
        stack.push 'anything'
        stack.pop()
        assert stack.peek() == 'c'
    }

    @Specification
    void shouldReturnTheTopItemWhenSentPeek() {
        assert stack.peek() == 'c'
    }

    @Specification
    void shouldNotRemoveTheTopItemWhenSentPeek() {
        assert stack.peek() == 'c'
        assert stack.peek() == 'c'
    }

    @Specification
    void shouldReturnTheTopItemWhenSentPop() {
        assert stack.pop() == 'c'
    }

    @Specification
    void shouldRemoveTheTopItemWhenSentPop() {
        assert stack.pop() == 'c'
        assert stack.pop() == 'b'
    }
}

TextRunner.runContexts(
    AlmostEmptyFixedStackContext,
    AlmostFullFixedStackContext,
    EmptyFixedStackContext,
    FullFixedStackContext,
    NonEmptyFixedStackContext
)

which outputs:

AlmostEmptyFixedStackContext
- shouldBecomeEmptyAfterPop
- shouldRemainNotEmptyAfterPeek
AlmostFullFixedStackContext
- shouldBecomeFullAfterPush
EmptyFixedStackContext
- shouldComplainWhenSentPeek
- shouldNoLongerBeEmptyAfterPush
- shouldComplainWhenSentPop
FullFixedStackContext
- shouldComplainOnPush
- shouldNoLongerBeFullAfterPop
- shouldRemainFullAfterPeek
NonEmptyFixedStackContext
- shouldAddToTheTopWhenSentPush
- shouldBeUnchangedWhenSentPushThenPop
- shouldReturnTheTopItemWhenSentPop
- shouldReturnTheTopItemWhenSentPeek
- shouldNotRemoveTheTopItemWhenSentPeek
- shouldRemoveTheTopItemWhenSentPop

The Item Storer Example

Here is how you might use Instinct to integration test the Item Storer Example:

// require(url:'http://code.google.com/p/instinct', jar:'instinct-0.1.5.jar')
// require(url:'http://geekscape.org/static/boost.html', jar:'boost-982.jar')
// require(groupId:'org.jmock', artifactId:'jmock', version:'2.2.0')
import com.googlecode.instinct.marker.annotate.BeforeSpecification as initially
import com.googlecode.instinct.marker.annotate.Specification as spec
import static com.googlecode.instinct.runner.TextRunner.runContexts as check_specs_for

class a_default_storer {
    def storer

    @initially void create_new_storer() {
        storer = new Storer()
    }

    private check_persist_and_reverse(value, expectedReverse) {
        storer.put(value)

        def persisted = storer.get()
        assert persisted == value

        def reversed = storer.reverse
        assert reversed == expectedReverse
    }

    @spec def should_reverse_numbers() {
        check_persist_and_reverse 123.456, -123.456
    }

    @spec def should_reverse_strings() {
        check_persist_and_reverse 'hello', 'olleh'
    }

    @spec def should_reverse_lists() {
        check_persist_and_reverse([1, 3, 5], [5, 3, 1])
    }
}

check_specs_for a_default_storer

We have used some BDD-flavoured method naming conventions here, but they are not compulsory. Here is the output:

a_default_storer
- should_reverse_lists
- should_reverse_strings
- should_reverse_numbers