The Art of Software Testing, Second Edition

9.3. Testing Strategies

Developing a testing strategy for Internet-based applications requires a solid understanding of each of the hardware and software components that make up the application. As is critical to successful testing of standard applications, a specification document is needed to describe the expected functionality and performance of your Website. Without this document, you cannot design the appropriate tests.

You need to test components developed internally and those purchased from a third party. For the components developed in-house you should employ the tactics presented in earlier chapters. This includes creating unit/module tests and performing code reviews. You should integrate the components into your system only after verifying that they meet the design specifications and functionality outlined in the specification document.

If you purchase components, then you need to develop a series of system tests to validate that the items perform correctly independently of your application. Do not rely on the vendor's quality-control program to detect errors in its components. Ideally, you should complete this task independently of your application testing. Integrate these components only once you determine that they perform acceptably. Including a nonfunctional third-party component in your architecture makes it difficult to interpret test results and identify the source of errors. Generally, you will use black-box approaches for third-party components because you ...