Adversaries study how you test to learn what you don’t test. They inventory static analyzers and coding standards (MISRA/C, CERT, CWE rulesets), dynamic tools (address/UB sanitizers, valgrind-class tools), fuzzers targeted at command parsers and protocols (e.g., CCSDS TC/TM, payload formats), property-based tests, mutation testing, coverage thresholds, and formal methods applied to mode logic or crypto. They also examine HIL setups, fault-injection frameworks, timing/jitter tests, and regression suites that gate release. Gaps, such as minimal negative testing on rare modes, weak corpus diversity, or untested rate/size limits, inform exploit design and the timing of inputs to evade FDIR or saturate queues.