Integrating testing into computing education has drawn increasing interest from both researchers and practitioners in recent years, fueled by the emergence of more robust testing paradigms and AI tools that make testing more accessible. Prior studies on this topic primarily focused on integrating testing into entry-level computer science (CS) courses. While these studies achieved some success, they are limited by their over-reliance on post-surveys for measuring impact and the lack of investigation into tool-agnostic pedagogical approaches that could effectively facilitate testing integration. To address these limitations, we investigated integrating behavior-driven development (BDD) into an intermediate-level algorithm course, using worked-out examples as instructional scaffolds to support student test case writing. BDD is a testing paradigm that emphasizes testing code behavior from the user’s perspective and has been widely adopted in industry due to its flexibility. Our results demonstrate that BDD can be successfully integrated into CS courses when worked-out examples are used as scaffolds to guide students in writing test cases. These findings contribute new insights into effective, tool-agnostic pedagogical strategies for integrating testing into the CS curriculum.