dependency-seam-detectionlisted

# Dependency Seam Detection Find hard-to-control dependencies and propose seams that make tests possible before refactor. ## Dependency smells - `new` inside business logic. - Static calls and singletons. - System clock, random, filesystem, environment, or global config. - Direct DB access, external services, queues, event buses, cache, threading, or async work. ## Seam options - Constructor injection. - Interface seam. - Object seam. - Wrapper or adapter. - Parameter injection. - Protected method seam. - Sprout method. - Sprout class. ## Seams and enabling points A seam is a place where behavior can be changed without editing the code at that place; every seam has an enabling point where the substitution is decided. Object seams (polymorphism, injection) are the default in OO code; link/classpath seams (test-time substitution of a dependency at the linker or classpath level) and preprocessing seams sit below them and matter when the code itself cannot be edited. ## Selection rule Prefer the least invasive technique that lets a test run: parameter or constructor injection before interface extraction, interface extraction before subclass-and-override, subclass-and-override before brute force. Dependency-breaking is medicine, not vitamins — a scar (a slightly awkward seam) is acceptable and gets cleaned up in a later refactor once tests exist. ## References - `references/dependency-breaking-catalog.md` — dependency-breaking catalog (WELC): four strategies, the individ