combinatorial-testing

Shrink an exponential combination space (feature flags, config options, API parameters) down to a minimal test matrix that still guarantees every pair of values is covered — pairwise/all-pairs testing, escalating to orthogonal arrays when 3-way interaction coverage is needed. Use eagerly whenever the user has 4+ independent parameters or flags and wants a test suite for them, mentions "too many combinations to test", "feature flag combinations", "config options interacting badly", "pairwise testing", "all-pairs", "orthogonal array", or describes a system where multiple independent settings can combine in ways nobody has fully tested. Don't reach for this when parameters are tightly interdependent (that's a decision-tables problem) or when there are only 2-3 conditions (exhaustive enumeration is cheaper than setting up pairwise coverage).