In the dynamic landscape of web development, ensuring the reliability and functionality of your NestJS modules is paramount. However, when dealing with modules that incorporate the powerful HttpService from @nestjs/axios, navigating the testing terrain can be a complex endeavour. In this blog post, we will delve into the challenges developers face when testing NestJS modules utilizing HttpService and explore the crucial role played by the RxJS TestScheduler in overcoming these hurdles. Additionally, we will unravel the intricacies of injecting HttpService into the test module, providing you with a comprehensive guide to fortify your testing strategies and ensure the robustness of your NestJS applications. Join me as we navigate through the pitfalls, armed with insights to enhance the efficacy of your testing suite.