From Hardware Dependencies to Testable Code: A PowerShell Refactoring Story

This story reveals a fundamental software engineering problem: when hardware I/O and business logic are intertwined, testing requires actual machines. By extracting the resource allocation algorithm into a pure function that accepts numerical parameters, the author eliminated the hardware dependency entirely. Now twelve test cases run on any CI system without a hypervisor. This pattern—separating concerns and injecting dependencies—is essential for building systems that are both testable and maintainable.