Applying Quality Assurance to your Tests
Posted by Pete McBreen 27 Feb 2022 at 22:13
Although Brian Marick was not the originator of the concept, I first heard about Soap Opera Tests from Brian. Rather than a test covering a single, simple scenario, instead exaggerate and complicate the scenario to push the system to see where the failures can occur. This gets around the problem that is often seen in Agile projects where the team tries to simplify the problem domain by ignoring what could be considered to be edge-cases and just addressing the simple scenarios.
The lens of a Soap Opera can be useful to review the test suite for an application that goes beyond the simplistic code coverage that is often reported from unit tests and component tests within a deployment pipeline
- How many tests (outside of unit tests) have a trivial sequence of setup, do action, check result, teardown, (or to use the Agile terms, how many tests are of the form Given, When, Then) rather than a connected sequence of transactions that represents a complex scenario?
- For parameterized tests, how many are truly distinct tests rather than just equivalent values that exercise the exact same code path?
- Are the System tests already covered by the Component level tests already implemented by the developers? (Typically the developer written tests may consider some possible failures, but miss others)
- Do the System tests touch multiple parts of the architecture as part of a test scenario? (This is where a Soap Opera mindset helps, making sure that the test addresses what happens at team and component boundaries.)
- Do the System tests address the full scope of the system and cover all interacting systems? (A common failing is that of not testing that the data replicated to the associated data lake/swamp/warehouse accurately represents the system data.)
Overall whenever evaluating a test, it is useful to know what risk is it addressing. Ideally any descriptive text included in the automated test case should include information about the motivation for the test, why it is important and the consequences of skipping the test. My take is that System tests should not be just repeating what can already be done by unit and component level tests (e.g. view and controller tests in Phoenix Testing terminology), they have to go beyond those simple scenarios and probe the interfaces between the various components.
Basically all tests have to answer the economic question as to what is the value of this test case?