check-factoring

check-factoring

Role: review the shard's structure.

Failure model: the code is correct but lives in the wrong place, so a branch cannot reach it, a boundary leaks, or two copies drift apart.

The authority is skills/shared/references/architecture.md (Functional Core / Imperative Shell, dependency direction inward, the pure, shell, and native-wrapper split). The placement source is the descriptor's :architecture :modules map (see skills/shared/references/project-descriptor.md).

Look for

1. Dependency-direction violations. A pure function that calls an effectful one (IO, state, platform, persistence, a native handle); the effectful callee may sit in the same module or another; the rule is at the function, not the module, since modules are cut by domain and may hold both. An effectful function that threads another module's live state where only data should cross; a cycle between two modules that are therefore one domain or have the boundary drawn wrong. A pure function may not know an effect exists.
2. Pure/effect and native leakage. IO, a clock, a global, a native call, a persistence write, or state mutation inside a PURE FUNCTION. A module that mixes pure and effectful functions is NOT a leak; modules are domain-based. Or pure decision logic (query construction, view-spec computation, plan or transaction-data building) buried inside an effectful function where a test cannot reach it. Or domain logic inside a native wrapper (the wrapper marshals; it does not decide).
3. Native edge leakage. A wrapper that reaches into a handle's internals from the calling language, or that holds domain logic instead of marshalling data in and data out. Handles are opaque; the calling language passes them back, never inspects them.
4. Duplication. The same nontrivial logic in two units. Cite both sites. The high-risk case is a new variant of an existing path: a second codec beside the first, a second transport beside the first, a windowed path beside the headless one. Check that it shares the existing machinery rather than copying it. A duplicated path drifts; the two must match and silently will not. Cite the original it should have reused.
5. Oversized units. Files past the project's size gate (the descriptor's QA lane carries the threshold when one is set; absent one, roughly 800 lines for a file, 200 for a function). The carve-out: a file split along a domain seam is fine; a file growing by accretion is a finding.
6. Mixed concerns. A function that builds data and applies the effect; a native body that allocates, computes, and reports; a handler that decides and persists. The core and shell split exists to separate these.
7. Decisions trapped in effect loops. A semantic choice inlined in an event loop or a callback when it could be a returned value the caller switches on (description, not instruction). The inverse is equally a finding: a wrapper layer introduced only to fake purity or enable mocking, when a direct data read in decision code is correct.
8. Dead structure. Public functions with one caller; parameters every caller passes identically; a record or struct that wraps a map without adding behavior.