Code Coverage and Test Coverage

When assessing code quality, there are various metrics and methods to do so. However, when referring to quality and coverage metrics, there is often confusion between code coverage and test coverage. In this lesson, we’ll define and clarify what each of them means and focus on the definition and value of code coverage to front-end web application developers.

Test coverage

Test coverage refers to the level of testing against requirements that we cover via all types of testing (functional, nonfunctional, API, security, accessibility, and more).

Within test coverage, we can also identify the platform coverage metric, which includes the required permutations of browser/OS and mobile/OS platforms. Within the tool stack landscape, there are application life cycle management (ALM) solutions as well as other test management tools that can measure and provide high-level metrics around test coverage.

Typically, the QA manager would build a test plan that specifies all the testing efforts that are planned for the software version under test. As part of the plan, the QA manager will also provide test coverage goals and criteria.

Running all testing types that are required based on the test plan should ensure not only the high quality of the release but also a decent test coverage percentage. Based on the pass/fail ratio, decision-makers will know whether the product is ready to be released or whether it has quality risks.

In many practices, test coverage encapsulates the following pillars: