Bottom-up Integration Testing with the Technique of Metamorphic Testing

In previous studies on the application of Metamorphic Testing (MT), testing was usually conducted at the system level directly, without any well-planned integration strategy. This could lead to a difficulty in constructing Metamorphic Relations (MRs), as well as tracking and debugging the faults. On the other hand, traditional integration testing requires extra cost. In this paper, we combine the bottom-up integration approach with MT to address all the above problems. We use the Feature Selection (FS) system to illustrate our method and a 2-phase MT is conducted. With this 2-phase MT method, we can ease the MR identification and provide a clear hierarchy to easily track and isolate the faults for a complex system. Moreover, since such an integration approach is logically achieved with MRs, it does not need to have those specific set-ups as required in traditional integration testing.