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Analysation of DSL modelling



Analyse feature combinations and interactions in DSL using the right QA Process. We may find certain combinations to be invalid. Record all the additional information regarding testing features such as short semantic descriptions, rationales for each feature, stakeholders and client programs interested in each feature, examples of systems with a given feature. Document constraints, default dependency rules, availability sites, binding sites, binding modes, open/closed attributes, and priorities.

Start with steps 1 and 2 in the form of a brainstorming session by writing down as many features as you can. Then try to cluster them and organize them into feature hierarchies while identifying the kinds of variability involved (i.e. alternative, optional etc.). Finally, refine the feature diagrams by checking different combinations of the variable features, adding new features, and writing down additional constraints. Maintain and update the initial feature models during the rest of the development cycle. You may also start new diagrams at any point during the development.

The feature diagram is very helpful during domain analysis. The DSL modelling for our openstreetmap example is not yet finished. In general it is unclear how to proceed once a feature diagram exists. I think in software engineering there is no “formula” which can be genetically applied on how to implement a piece of software from a design model. Like in software engineering there are engineering skills necessary to transfer a feature diagram into a DSL. One thing that definitely helps to bridge this gap is the decision on how to implement the DSL in the first place. Most of the testing professionals from reputed testing firms prefer using a python integration into the process because it helps in covering various aspects without compromising on the quality. It helps to implement a DSL in Python is covered in the next section.

In fact the implementations of commands for the external DSL and internal DSL are almost identical in this approach. This means no additional effort for the implementation of the commands. The best thing is that during the start phase when you work with three or four commands, these can be modified without the need to change the grammar of the external DSL.

DSL Automation

When automating test cases Professional Testing firms always have a look at the manual test cases first. Manual test cases should be described in a way that a relatively inexperienced tester, who has read the application user guide, can execute the test case and verify the results. I think DSLs for test automation usually start small with about three to five implemented commands. These commands are used to formulate a couple of test cases. I have to adjust the commands a couple of times during this process until they perfectly fit my needs. The language grows step by step along the project. During maintenance of the test suite it will often be necessary to adjust the implementation of the commands due to changes in the GUI of the system under test.

The sample shows a test case formulated in the external DSL. The test case is formulated in natural language which allows us to involve domain experts in the test automation project. The test case describes two different scenarios for location search. The first scenario is the search in the View tab which does not require the user to log in. The second scenario tests the location search in the Edit tab which requires a login.