testability-canary

Testability Canary (Decoupling & Mockability Audit)

Language: Generate EVERYTHING at runtime in the user's language — questions, answer options, menu labels, recommendations, report narrative. Detect from their messages; never default to English just because this file is English. English is allowed only for technical terms: commands, paths, code identifiers, severity labels (CRITICAL/HIGH/MEDIUM/LOW), and tier names (Light/Standard/Heavy).

Config reads — every config key, always the CASCADE, never the bare project file: ~/.claude/.coalmine.json first, then the project config (own agent dir → other known agent dirs → legacy <gitroot>/.coalmine.json), project wins per key. A bare project read is ABSENT on a machine configured only globally, so it silently yields defaults.

Audit code to ensure it is decoupled, modular, and easy to cover with automated tests.

Auditing Categories

1. Hardcoded Constructors — instantiating deps inside classes (new DatabaseClient()) instead of injecting via constructor/factory (prevents mocking).
2. SRP Violations — a class or method doing too many distinct duties (e.g. a service that also parses JSON and formats UI).
3. Static Dependencies — reliance on global static methods or Singletons that make test isolation impossible.
4. Time & Environment Coupling — direct DateTime.Now, fs, or process.env calls without an abstraction layer (fragile time/path-sensitive tests).
5. Private Logic Gaps — complex business logic hidden in private methods that can't be tested directly (extract to testable helpers).

Per-stack patterns and the mock-strategy vocabulary: read references/checks.md before scanning.

Fix mode (choice-gated)

In Agent Context, after the report, present via ask_question:

• Apply safe refactoring: extract hardcoded initializations into constructor params (DI) + add interface definitions. Each fix: checkpoint (git stash/commit in a git repo; else copy the file aside — never assume git) → apply → build + tests → auto-revert if newly red.
• Let me pick: user selects specific refactoring moves.
• Report only: exit unchanged.