We studied the programming and debugging processes of an autonomous mobile social robot with a focus on the programmers. This process is time-consuming in a populated environment where a mobile social robot is designed to interact with real pedestrians. From our observations, we identified two types of time-wasting behaviors among programmers: cherry-picking and a shortage of coverage in their testing. We developed a new tool, a test generator framework, to help avoid these testing time-wasters. This framework generates new testing scenarios to be used in a simulator by blending a user-prepared test with pre-stored pedestrian patterns. Finally, we conducted a user study to verify the effects of our test generator. The results showed that our test generator significantly reduced the programming and debugging time needed for autonomous mobile social robots.