G22: Logical to Physical Dependencies

The Problem of Silent Assumptions

G22: A logical dependency is an assumption your code makes about another module's state without declaring it in code. Module A uses a constant it assumes is defined in module B. If B changes that constant, A breaks silently at runtime, not at compile time. Logical dependencies are invisible to the compiler, the linter, and the reviewer — they are bugs waiting for a version bump. Physical dependencies are declared: your code imports the value, receives it as a parameter, or references a shared source — and the build system can verify it.

Making Dependencies Explicit

The rule: if your code's correctness depends on a value, that value must appear explicitly in your code — not be assumed. Strategies: (1) pass the value as a parameter; (2) inject the dependency; (3) import from a shared constants module. Every duplicated constant is a hidden logical dependency waiting to diverge. When you see the same magic number in two places, one of them will be updated and the other won't.