What is inside the base of the pyramid?
The base of the pyramid contains those tests that are closest to the development of the feature. Although there are some discrepancies around this claim, it is usually where most tests should take place. The reason is that the earlier the issues are found, the cheaper it is to fix them. In this case, the monetary value of finding an issue is measured by the amount of time spent figuring out why it has happened (debugging) plus the amount of time spent fixing it and the context switch needed if the developer has moved on to a different task.
Tests closest to the feature’s development are sometimes referred to as “structural.” In the 2D test pyramid (or triangle), the tests that are located here are unit tests.
Most developers include testing tools and processes in their development, although, interestingly, some of the tools and processes are not even considered as part of quality by them. Some developers claim that...
