BDD - AND Specifications
The current project I am involved in, we are using BDD style of testing, where our specifications (tests) are both designing force and documentation for the implementation. One of the interesting cases we are running into, is when we need to express some complex conditions. For example
When a component is asked to perform some action on some object
- Should do A
- Should do B
Then we add complexity by trying to look into what is going to happen when
- instance of some object is valid
- instance of some object is invalid
So far it’s working nicely, and code looks like this
1: public class When_component_is_asked_to_perform_some_action_on_some_other_object : Component_Specs
<pre style="padding-right: 0px; padding-left: 0px; font-size: 8pt; padding-bottom: 0px; margin: 0em; overflow: visible; width: 100%; color: black; border-top-style: none; line-height: 12pt; padding-top: 0px; font-family: consolas, 'Courier New', courier, monospace; border-right-style: none; border-left-style: none; background-color: #f4f4f4; border-bottom-style: none"><span style="color: #606060"> 2:</span> {</pre>
<pre style="padding-right: 0px; padding-left: 0px; font-size: 8pt; padding-bottom: 0px; margin: 0em; overflow: visible; width: 100%; color: black; border-top-style: none; line-height: 12pt; padding-top: 0px; font-family: consolas, 'Courier New', courier, monospace; border-right-style: none; border-left-style: none; background-color: white; border-bottom-style: none"><span style="color: #606060"> 3:</span> [Observation]</pre>
<pre style="padding-right: 0px; padding-left: 0px; font-size: 8pt; padding-bottom: 0px; margin: 0em; overflow: visible; width: 100%; color: black; border-top-style: none; line-height: 12pt; padding-top: 0px; font-family: consolas, 'Courier New', courier, monospace; border-right-style: none; border-left-style: none; background-color: #f4f4f4; border-bottom-style: none"><span style="color: #606060"> 4:</span> <span style="color: #0000ff">public</span> <span style="color: #0000ff">void</span> Should_do_A() {}</pre>
<pre style="padding-right: 0px; padding-left: 0px; font-size: 8pt; padding-bottom: 0px; margin: 0em; overflow: visible; width: 100%; color: black; border-top-style: none; line-height: 12pt; padding-top: 0px; font-family: consolas, 'Courier New', courier, monospace; border-right-style: none; border-left-style: none; background-color: white; border-bottom-style: none"><span style="color: #606060"> 5:</span>  </pre>
<pre style="padding-right: 0px; padding-left: 0px; font-size: 8pt; padding-bottom: 0px; margin: 0em; overflow: visible; width: 100%; color: black; border-top-style: none; line-height: 12pt; padding-top: 0px; font-family: consolas, 'Courier New', courier, monospace; border-right-style: none; border-left-style: none; background-color: #f4f4f4; border-bottom-style: none"><span style="color: #606060"> 6:</span> [Observation]</pre>
<pre style="padding-right: 0px; padding-left: 0px; font-size: 8pt; padding-bottom: 0px; margin: 0em; overflow: visible; width: 100%; color: black; border-top-style: none; line-height: 12pt; padding-top: 0px; font-family: consolas, 'Courier New', courier, monospace; border-right-style: none; border-left-style: none; background-color: white; border-bottom-style: none"><span style="color: #606060"> 7:</span> <span style="color: #0000ff">public</span> <span style="color: #0000ff">void</span> Should_do_B() {}</pre>
<pre style="padding-right: 0px; padding-left: 0px; font-size: 8pt; padding-bottom: 0px; margin: 0em; overflow: visible; width: 100%; color: black; border-top-style: none; line-height: 12pt; padding-top: 0px; font-family: consolas, 'Courier New', courier, monospace; border-right-style: none; border-left-style: none; background-color: #f4f4f4; border-bottom-style: none"><span style="color: #606060"> 8:</span> }</pre>
<pre style="padding-right: 0px; padding-left: 0px; font-size: 8pt; padding-bottom: 0px; margin: 0em; overflow: visible; width: 100%; color: black; border-top-style: none; line-height: 12pt; padding-top: 0px; font-family: consolas, 'Courier New', courier, monospace; border-right-style: none; border-left-style: none; background-color: white; border-bottom-style: none"><span style="color: #606060"> 9:</span>  </pre>
<pre style="padding-right: 0px; padding-left: 0px; font-size: 8pt; padding-bottom: 0px; margin: 0em; overflow: visible; width: 100%; color: black; border-top-style: none; line-height: 12pt; padding-top: 0px; font-family: consolas, 'Courier New', courier, monospace; border-right-style: none; border-left-style: none; background-color: #f4f4f4; border-bottom-style: none"><span style="color: #606060"> 10:</span> <span style="color: #0000ff">public</span> <span style="color: #0000ff">class</span> And_some_other_object_is_valid : When_component_is_asked_to_perform_some_action_on_some_other_object</pre>
<pre style="padding-right: 0px; padding-left: 0px; font-size: 8pt; padding-bottom: 0px; margin: 0em; overflow: visible; width: 100%; color: black; border-top-style: none; line-height: 12pt; padding-top: 0px; font-family: consolas, 'Courier New', courier, monospace; border-right-style: none; border-left-style: none; background-color: white; border-bottom-style: none"><span style="color: #606060"> 11:</span> {</pre>
<pre style="padding-right: 0px; padding-left: 0px; font-size: 8pt; padding-bottom: 0px; margin: 0em; overflow: visible; width: 100%; color: black; border-top-style: none; line-height: 12pt; padding-top: 0px; font-family: consolas, 'Courier New', courier, monospace; border-right-style: none; border-left-style: none; background-color: #f4f4f4; border-bottom-style: none"><span style="color: #606060"> 12:</span> [Observation]</pre>
<pre style="padding-right: 0px; padding-left: 0px; font-size: 8pt; padding-bottom: 0px; margin: 0em; overflow: visible; width: 100%; color: black; border-top-style: none; line-height: 12pt; padding-top: 0px; font-family: consolas, 'Courier New', courier, monospace; border-right-style: none; border-left-style: none; background-color: white; border-bottom-style: none"><span style="color: #606060"> 13:</span> <span style="color: #0000ff">public</span> <span style="color: #0000ff">void</span> Should_happen_something_when_some_object_is_valid() {}</pre>
<pre style="padding-right: 0px; padding-left: 0px; font-size: 8pt; padding-bottom: 0px; margin: 0em; overflow: visible; width: 100%; color: black; border-top-style: none; line-height: 12pt; padding-top: 0px; font-family: consolas, 'Courier New', courier, monospace; border-right-style: none; border-left-style: none; background-color: #f4f4f4; border-bottom-style: none"><span style="color: #606060"> 14:</span>  </pre>
<pre style="padding-right: 0px; padding-left: 0px; font-size: 8pt; padding-bottom: 0px; margin: 0em; overflow: visible; width: 100%; color: black; border-top-style: none; line-height: 12pt; padding-top: 0px; font-family: consolas, 'Courier New', courier, monospace; border-right-style: none; border-left-style: none; background-color: white; border-bottom-style: none"><span style="color: #606060"> 15:</span> }</pre>
<pre style="padding-right: 0px; padding-left: 0px; font-size: 8pt; padding-bottom: 0px; margin: 0em; overflow: visible; width: 100%; color: black; border-top-style: none; line-height: 12pt; padding-top: 0px; font-family: consolas, 'Courier New', courier, monospace; border-right-style: none; border-left-style: none; background-color: #f4f4f4; border-bottom-style: none"><span style="color: #606060"> 16:</span>  </pre>
<pre style="padding-right: 0px; padding-left: 0px; font-size: 8pt; padding-bottom: 0px; margin: 0em; overflow: visible; width: 100%; color: black; border-top-style: none; line-height: 12pt; padding-top: 0px; font-family: consolas, 'Courier New', courier, monospace; border-right-style: none; border-left-style: none; background-color: white; border-bottom-style: none"><span style="color: #606060"> 17:</span> <span style="color: #0000ff">public</span> <span style="color: #0000ff">class</span> And_some_other_object_is_invalid : When_component_is_asked_to_perform_some_action_on_some_other_object</pre>
<pre style="padding-right: 0px; padding-left: 0px; font-size: 8pt; padding-bottom: 0px; margin: 0em; overflow: visible; width: 100%; color: black; border-top-style: none; line-height: 12pt; padding-top: 0px; font-family: consolas, 'Courier New', courier, monospace; border-right-style: none; border-left-style: none; background-color: #f4f4f4; border-bottom-style: none"><span style="color: #606060"> 18:</span> {</pre>
<pre style="padding-right: 0px; padding-left: 0px; font-size: 8pt; padding-bottom: 0px; margin: 0em; overflow: visible; width: 100%; color: black; border-top-style: none; line-height: 12pt; padding-top: 0px; font-family: consolas, 'Courier New', courier, monospace; border-right-style: none; border-left-style: none; background-color: white; border-bottom-style: none"><span style="color: #606060"> 19:</span> [Observation]</pre>
<pre style="padding-right: 0px; padding-left: 0px; font-size: 8pt; padding-bottom: 0px; margin: 0em; overflow: visible; width: 100%; color: black; border-top-style: none; line-height: 12pt; padding-top: 0px; font-family: consolas, 'Courier New', courier, monospace; border-right-style: none; border-left-style: none; background-color: #f4f4f4; border-bottom-style: none"><span style="color: #606060"> 20:</span> <span style="color: #0000ff">public</span> <span style="color: #0000ff">void</span> Should_happen_something_else_when_some_object_is_invalid() {}</pre>
<pre style="padding-right: 0px; padding-left: 0px; font-size: 8pt; padding-bottom: 0px; margin: 0em; overflow: visible; width: 100%; color: black; border-top-style: none; line-height: 12pt; padding-top: 0px; font-family: consolas, 'Courier New', courier, monospace; border-right-style: none; border-left-style: none; background-color: white; border-bottom-style: none"><span style="color: #606060"> 21:</span>  </pre>
<pre style="padding-right: 0px; padding-left: 0px; font-size: 8pt; padding-bottom: 0px; margin: 0em; overflow: visible; width: 100%; color: black; border-top-style: none; line-height: 12pt; padding-top: 0px; font-family: consolas, 'Courier New', courier, monospace; border-right-style: none; border-left-style: none; background-color: #f4f4f4; border-bottom-style: none"><span style="color: #606060"> 22:</span> }</pre>
The problem started when there were 10 passing tests instead of 6. Well, good that they all were passing, but what’s the catch? Apparently, the When_component_is_asked_to_perform_some_action_on_some_other_object class was running on it’s own, in addition to the AND specifications that included its’ observations by inheritance. Solution was simple, don’t let the testing framework instantiate the base specification.
1: public abstract class When_component_is_asked_to_perform_some_action_on_some_other_object : Component_Specs
<pre style="padding-right: 0px; padding-left: 0px; font-size: 8pt; padding-bottom: 0px; margin: 0em; overflow: visible; width: 100%; color: black; border-top-style: none; line-height: 12pt; padding-top: 0px; font-family: consolas, 'Courier New', courier, monospace; border-right-style: none; border-left-style: none; background-color: #f4f4f4; border-bottom-style: none"><span style="color: #606060"> 2:</span> {</pre>
<pre style="padding-right: 0px; padding-left: 0px; font-size: 8pt; padding-bottom: 0px; margin: 0em; overflow: visible; width: 100%; color: black; border-top-style: none; line-height: 12pt; padding-top: 0px; font-family: consolas, 'Courier New', courier, monospace; border-right-style: none; border-left-style: none; background-color: white; border-bottom-style: none"><span style="color: #606060"> 3:</span> [Observation]</pre>
<pre style="padding-right: 0px; padding-left: 0px; font-size: 8pt; padding-bottom: 0px; margin: 0em; overflow: visible; width: 100%; color: black; border-top-style: none; line-height: 12pt; padding-top: 0px; font-family: consolas, 'Courier New', courier, monospace; border-right-style: none; border-left-style: none; background-color: #f4f4f4; border-bottom-style: none"><span style="color: #606060"> 4:</span> <span style="color: #0000ff">public</span> <span style="color: #0000ff">void</span> Should_do_A() {}</pre>
<pre style="padding-right: 0px; padding-left: 0px; font-size: 8pt; padding-bottom: 0px; margin: 0em; overflow: visible; width: 100%; color: black; border-top-style: none; line-height: 12pt; padding-top: 0px; font-family: consolas, 'Courier New', courier, monospace; border-right-style: none; border-left-style: none; background-color: white; border-bottom-style: none"><span style="color: #606060"> 5:</span>  </pre>
<pre style="padding-right: 0px; padding-left: 0px; font-size: 8pt; padding-bottom: 0px; margin: 0em; overflow: visible; width: 100%; color: black; border-top-style: none; line-height: 12pt; padding-top: 0px; font-family: consolas, 'Courier New', courier, monospace; border-right-style: none; border-left-style: none; background-color: #f4f4f4; border-bottom-style: none"><span style="color: #606060"> 6:</span> [Observation]</pre>
<pre style="padding-right: 0px; padding-left: 0px; font-size: 8pt; padding-bottom: 0px; margin: 0em; overflow: visible; width: 100%; color: black; border-top-style: none; line-height: 12pt; padding-top: 0px; font-family: consolas, 'Courier New', courier, monospace; border-right-style: none; border-left-style: none; background-color: white; border-bottom-style: none"><span style="color: #606060"> 7:</span> <span style="color: #0000ff">public</span> <span style="color: #0000ff">void</span> Should_do_B() {}</pre>
<pre style="padding-right: 0px; padding-left: 0px; font-size: 8pt; padding-bottom: 0px; margin: 0em; overflow: visible; width: 100%; color: black; border-top-style: none; line-height: 12pt; padding-top: 0px; font-family: consolas, 'Courier New', courier, monospace; border-right-style: none; border-left-style: none; background-color: #f4f4f4; border-bottom-style: none"><span style="color: #606060"> 8:</span> }</pre>
<pre style="padding-right: 0px; padding-left: 0px; font-size: 8pt; padding-bottom: 0px; margin: 0em; overflow: visible; width: 100%; color: black; border-top-style: none; line-height: 12pt; padding-top: 0px; font-family: consolas, 'Courier New', courier, monospace; border-right-style: none; border-left-style: none; background-color: white; border-bottom-style: none"><span style="color: #606060"> 9:</span>  </pre>
<pre style="padding-right: 0px; padding-left: 0px; font-size: 8pt; padding-bottom: 0px; margin: 0em; overflow: visible; width: 100%; color: black; border-top-style: none; line-height: 12pt; padding-top: 0px; font-family: consolas, 'Courier New', courier, monospace; border-right-style: none; border-left-style: none; background-color: #f4f4f4; border-bottom-style: none"><span style="color: #606060"> 10:</span> <span style="color: #0000ff">public</span> <span style="color: #0000ff">class</span> And_some_other_object_is_valid : When_component_is_asked_to_perform_some_action_on_some_other_object</pre>
<pre style="padding-right: 0px; padding-left: 0px; font-size: 8pt; padding-bottom: 0px; margin: 0em; overflow: visible; width: 100%; color: black; border-top-style: none; line-height: 12pt; padding-top: 0px; font-family: consolas, 'Courier New', courier, monospace; border-right-style: none; border-left-style: none; background-color: white; border-bottom-style: none"><span style="color: #606060"> 11:</span> {</pre>
<pre style="padding-right: 0px; padding-left: 0px; font-size: 8pt; padding-bottom: 0px; margin: 0em; overflow: visible; width: 100%; color: black; border-top-style: none; line-height: 12pt; padding-top: 0px; font-family: consolas, 'Courier New', courier, monospace; border-right-style: none; border-left-style: none; background-color: #f4f4f4; border-bottom-style: none"><span style="color: #606060"> 12:</span> [Observation]</pre>
<pre style="padding-right: 0px; padding-left: 0px; font-size: 8pt; padding-bottom: 0px; margin: 0em; overflow: visible; width: 100%; color: black; border-top-style: none; line-height: 12pt; padding-top: 0px; font-family: consolas, 'Courier New', courier, monospace; border-right-style: none; border-left-style: none; background-color: white; border-bottom-style: none"><span style="color: #606060"> 13:</span> <span style="color: #0000ff">public</span> <span style="color: #0000ff">void</span> Should_happen_something_when_some_object_is_valid() {}</pre>
<pre style="padding-right: 0px; padding-left: 0px; font-size: 8pt; padding-bottom: 0px; margin: 0em; overflow: visible; width: 100%; color: black; border-top-style: none; line-height: 12pt; padding-top: 0px; font-family: consolas, 'Courier New', courier, monospace; border-right-style: none; border-left-style: none; background-color: #f4f4f4; border-bottom-style: none"><span style="color: #606060"> 14:</span>  </pre>
<pre style="padding-right: 0px; padding-left: 0px; font-size: 8pt; padding-bottom: 0px; margin: 0em; overflow: visible; width: 100%; color: black; border-top-style: none; line-height: 12pt; padding-top: 0px; font-family: consolas, 'Courier New', courier, monospace; border-right-style: none; border-left-style: none; background-color: white; border-bottom-style: none"><span style="color: #606060"> 15:</span> }</pre>
<pre style="padding-right: 0px; padding-left: 0px; font-size: 8pt; padding-bottom: 0px; margin: 0em; overflow: visible; width: 100%; color: black; border-top-style: none; line-height: 12pt; padding-top: 0px; font-family: consolas, 'Courier New', courier, monospace; border-right-style: none; border-left-style: none; background-color: #f4f4f4; border-bottom-style: none"><span style="color: #606060"> 16:</span>  </pre>
<pre style="padding-right: 0px; padding-left: 0px; font-size: 8pt; padding-bottom: 0px; margin: 0em; overflow: visible; width: 100%; color: black; border-top-style: none; line-height: 12pt; padding-top: 0px; font-family: consolas, 'Courier New', courier, monospace; border-right-style: none; border-left-style: none; background-color: white; border-bottom-style: none"><span style="color: #606060"> 17:</span> <span style="color: #0000ff">public</span> <span style="color: #0000ff">class</span> And_some_other_object_is_invalid : When_component_is_asked_to_perform_some_action_on_some_other_object</pre>
<pre style="padding-right: 0px; padding-left: 0px; font-size: 8pt; padding-bottom: 0px; margin: 0em; overflow: visible; width: 100%; color: black; border-top-style: none; line-height: 12pt; padding-top: 0px; font-family: consolas, 'Courier New', courier, monospace; border-right-style: none; border-left-style: none; background-color: #f4f4f4; border-bottom-style: none"><span style="color: #606060"> 18:</span> {</pre>
<pre style="padding-right: 0px; padding-left: 0px; font-size: 8pt; padding-bottom: 0px; margin: 0em; overflow: visible; width: 100%; color: black; border-top-style: none; line-height: 12pt; padding-top: 0px; font-family: consolas, 'Courier New', courier, monospace; border-right-style: none; border-left-style: none; background-color: white; border-bottom-style: none"><span style="color: #606060"> 19:</span> [Observation]</pre>
<pre style="padding-right: 0px; padding-left: 0px; font-size: 8pt; padding-bottom: 0px; margin: 0em; overflow: visible; width: 100%; color: black; border-top-style: none; line-height: 12pt; padding-top: 0px; font-family: consolas, 'Courier New', courier, monospace; border-right-style: none; border-left-style: none; background-color: #f4f4f4; border-bottom-style: none"><span style="color: #606060"> 20:</span> <span style="color: #0000ff">public</span> <span style="color: #0000ff">void</span> Should_happen_something_else_when_some_object_is_invalid() {}</pre>
<pre style="padding-right: 0px; padding-left: 0px; font-size: 8pt; padding-bottom: 0px; margin: 0em; overflow: visible; width: 100%; color: black; border-top-style: none; line-height: 12pt; padding-top: 0px; font-family: consolas, 'Courier New', courier, monospace; border-right-style: none; border-left-style: none; background-color: white; border-bottom-style: none"><span style="color: #606060"> 21:</span>  </pre>
<pre style="padding-right: 0px; padding-left: 0px; font-size: 8pt; padding-bottom: 0px; margin: 0em; overflow: visible; width: 100%; color: black; border-top-style: none; line-height: 12pt; padding-top: 0px; font-family: consolas, 'Courier New', courier, monospace; border-right-style: none; border-left-style: none; background-color: #f4f4f4; border-bottom-style: none"><span style="color: #606060"> 22:</span> }</pre>
Moral: passing tests is important. Having clean and manageable tests is no less important.