Specs and Fixtures/Contexts

This topic revisits the Specs BDD testing library. It is a continuation of the previous post Specs BDD Testing Framework.

This topic will look at how to setup fixtures in Specs. This is only a sample to give a feeling of Specs a much more complete guide is available on the Specs website.

1. jeichar: git-src$ scala -classpath ~/.m2/repository/org/scala-tools/testing/specs/1.6.1/specs-1.6.1.jar
3. scala> import org.specs._
4. import org.specs._
6. /*
7. This example demonstrates before and after actions similar to what is found in XUnit.
8. */
9. scala> object mySpec extends Specification {           
10.      | "my system" should {
11.      | doFirst{println("before")}  // ran once
12.      | 
13.      | doBefore{println("before")} // ran for each test
14.      | doAfter{println("after")} // ran for each test
15.      | 
16.      | "test spec 1" in { println("test1"); 1 must_== 1}
17.      | "test spec 2" in { println("test2"); 1 must_== 2}
18.      | 
19.      | doLast{println("last")} // ran once
20.      | }}
21. defined module mySpec
23. scala> mySpec.main(Array())                             
24. Specification "mySpec"
25.   my system should
26. before
27. before
28. test1
29. after
30.   + test spec 1
31. before
32. test2
33. after
34. last
35.   x test spec 2
36.     '1' is not equal to '2' (< console>:14)
38. Total for specification "mySpec":
39. Finished in 0 second, 307 ms
40. 2 examples, 2 expectations, 1 failure, 0 error

Example using Contexts there many more examples at: Shared contexts

1. scala> import org.specs._
2. import org.specs._
4. /*
5. This specification uses contexts instead of before and after actions.
7. My personal preference is to use contexts because they are more flexible and can have names associated with them.  In addition contexts can be shared between specifications and multiple contexts can be used within a single specification.  This example is kept very simple for demonstration purposes
8. */
9. scala> object StackSpecification extends Specification {
10.      |   var list : List[Int] = _
11.      |   val empty = beforeContext(list = Nil)  
12.      |   val nonEmpty = beforeContext(list = List(1,2,3))
13.      |   
14.      |   "A full stack" definedAs nonEmpty should { 
15.      |     "size of 3" in {
16.      |       list must haveSize (3)
17.      |     }
18.      |   }
19.      |   "A stack" when empty should { 
20.      |     "is empty" in {
21.      |       list must beEmpty
22.      |     }
23.      |   }
24.      | }
25. defined module StackSpecification
27. scala> StackSpecification.main(Array())
28. Specification "StackSpecification"
29.   A full stack should
30.   + size of 3
32.   Total for SUS "A full stack":
33.   Finished in 0 second, 42 ms
34.   1 example, 1 expectation, 0 failure, 0 error
36.   A stack should
37.   + is empty
39.   Total for SUS "A stack":
40.   Finished in 0 second, 4 ms
41.   1 example, 1 expectation, 0 failure, 0 error
43. Total for specification "StackSpecification":
44. Finished in 0 second, 85 ms
45. 2 examples, 2 expectations, 0 failure, 0 error

Specs BDD Testing framework

This is the second Scala test framework topic and focuses on the excellent Specs framework. The other topic was on ScalaTest, another excellent testing framework for Scala.

Specs is focussed on BDD testing (Behaviour Driven Design) and is the inspiration for ScalaTests WordSpec. From what I understand Specs was in-turn inspired by RSpec the Ruby BDD testing framework.

Specs has some truly unique features to it which we will encounter in future topics. But for now just the basics. The following example tests a couple of Scala's XML support in order to demonstract the general pattern followed when writing Specs' tests.

1. # scala -classpath ~/.m2/repository/org/scala-tools/testing/specs/1.6.1/specs-1.6.1.jar
3. scala> import org.specs._
4. import org.specs._
6. scala> object XmlSpec extends Specification {
7.      |  val sample = <library>
8.      |         <videos>
9.      |         <video type="dvd">Seven</video>
10.      |         <video type="blue-ray">The fifth element</video>
11.      |         <video type="hardcover">Gardens of the moon</video>
12.      |         </videos>
13.      |         <books>
14.      |         <book type="softcover">Memories of Ice</book>
15.      |         </books>
16.      |         </library>
17.      |  "Scala XML" should {
18.      |   "allow xpath-like selection" in {
19.      |    (sample \\ "video").size must be (3)    
20.      |   }
21.      |   "select child nodes" in {
22.      |    // This test fails because child is a sequence not a string
23.      |    // See the results of the tests
24.      |    sample.child must contain (<videos/>)
25.      |   }
26.      |  }
27.      |  }
28. defined module XmlSpec
30. scala> XmlSpec.main(Array[String]())
31. Specification "XmlSpec"
32.   Scala XML should
33.   + allow xpath-like selection
34.   x select child nodes <-- x indicates failure.
35.     'ArrayBuffer(
36.                    , <videos>
37.                    <video type="dvd">Seven</video>
38.                    <video type="blue-ray">The fifth element</video>
39.                    <video type="hardcover">Gardens of the moon</video>
40.                    </videos>, 
41.                    , <books>
42.                    <book type="softcover">Memories of Ice</book>
43.                    </books>, 
44.                    )' doesn't contain '<videos></videos>' (< console>:24)
46. Total for specification "XmlSpec":
47. Finished in 0 second, 52 ms
48. 2 examples, 2 expectations, 1 failure, 0 error