View source for INDEPENDENT TEST CASES

<div id="content_view" class="wiki" style="display: block"><span style="font-size: 14px">.................................................................................................................[[Main Page]] / Back to [[Design Patterns]] / Back to [[Test Automation Patterns]]</span>
=<span style="font-size: 16px">Pattern summary</span>=
<span style="font-size: 16px">Make each automated test case self-contained</span>
=<span style="font-size: 16px">Category</span>=
<span style="font-size: 16px">Design</span>
=<span style="font-size: 16px">Context</span>=
<span style="font-size: 16px">This pattern is necessary if you want to implement long lasting and efficient test automation.</span><br /> <span style="font-size: 16px">An exception is when one test specifically checks the results from the prior test (e.g., using a separate test to ensure data was written into a database and not just retrieved from working memory).</span><br /> <span style="font-size: 16px">It is not necessary for just writing disposable scripts.</span>
=<span style="font-size: 16px">Description</span>=
<span style="font-size: 16px">Automated test cases run independently of each other, so that they can be started separately and are not affected if tests running earlier have failed. The test may consist of a large number of different scripts or actions, some to set up the conditions needed for a test, others to execute the test steps. </span><br /> <br /> <span style="font-size: 16px">Automated tests should be short and well-defined. For example, if you have one long test that takes 30 minutes to run, maybe it fails after 5 minutes the first time, after 10 the next and after 15 the 3rd time. So far you have used half an hour and have 3 bugs (which you have fixed). But you are only half-way through the test. If you separate that test into 10 tests of 3 minutes each, you can start all of them. If you can run them in parallel, execution will only take 3 minutes. Maybe 3 or 4 of them fail, but you now know that all of the others have passed, so after you fix these, the whole set of tests should be passing, and it takes a lot less time.</span>
=<span style="font-size: 16px">Implementation</span>=
* <span style="font-size: 16px">Every test starts with a [[FRESH SETUP]] before performing any action. Each test has proprietary access to its resources.</span>
* <span style="font-size: 16px">If a test fails (stops before completion), it must reset the Software Under Test (SUT) and or the tool so that the following tests can run normally (see the pattern [[FAIL GRACEFULLY]])</span>
* <span style="font-size: 16px">A self contained test does NOT mean that just one test case tests the whole application! On the contrary each test should have [[ONE CLEAR PURPOSE ]]derived from one business rule.</span>
* <span style="font-size: 16px">If you [[PRIORITIZE TESTS]], you will also be able to run or rerun the tests independently from each other.</span>
=<span style="font-size: 16px">Possible problems</span>=
<span style="font-size: 16px">Manual tests are often performed sequentially in order to spare set-up time. They should be redesigned before automating to make sure that the automation is as efficient as possible.</span><br /> <span style="font-size: 16px">If the initial set-up is very complicated or takes too much time and there is no other option, then this pattern should not be used, instead use [[CHAINED TESTS]].</span>
=<span style="font-size: 16px">Issues addressed by this pattern</span>=
''<span style="font-size: 16px">[[FALSE FAIL]]</span>''<br /> ''<span style="font-size: 16px">[[FLAKY TESTS]]</span>''<br /> ''<span style="font-size: 16px">[[INEFFICIENT EXECUTION]]</span>''<br /> ''<span style="font-size: 16px">[[INFLEXIBLE AUTOMATION]]</span>''<br /> ''<span style="font-size: 16px">[[INTERDEPENDENT TEST CASES]]</span>''<br /> ''<span style="font-size: 16px">[[OBSCURE TESTS]]</span>''
=<span style="font-size: 16px">Experiences</span>=
<span style="font-size: 16px">If you have used this pattern, please add your name and a brief story of how you used this pattern: your context, what you did, and how well it worked - or how it didn't work!</span><br /> <br /> <span style="font-size: 14px">.................................................................................................................[[Main Page]] / Back to [[ Design Patterns]] / Back to [[Test Automation Patterns]]</span><br /> <span style="font-size: 14px">B5</span></div>