paulnsorensen Sliced Bread Review
Review the target change set against the Sliced Bread architecture. The full rationale lives at https://cheeselord.dev/sliced-bread-architecture/reference/sliced-bread/; this skill is the operational checklist.
Scope
Determine the review target from the invocation, in priority order:
- An explicit path, diff, branch, or PR named by the user.
- The current branch's diff against the default branch.
- Uncommitted changes (
git diff HEAD).
Review only the changed files plus any file a changed import points at.
The Five Checks
Run every check against every changed file. Cite file:line and quote the
offending import or definition for each finding.
1. Import direction
Arrows may only point in a permitted direction. Only the composition root
(app/bootstrap, main) may import concrete adapters, and nothing imports
entrypoints/. A slice may import a sibling slice's public seam directly.
The arrows describe permitted direction, not required directories — a repo with
no entrypoints/ layer is not in violation.
entrypoints/ -> app/ -> domains/* -> domains/common/
app/bootstrap -> adapters/ (composition root only)
adapters/ -> domains/* (implement domain ports)
Never:
app/use_cases/* -> adapters/*
domains/* -> adapters/ | app/ | entrypoints/
adapters/* -> app/ | entrypoints/
common/ -> sibling domains
anything -> entrypoints/
Any inversion of these arrows is a blocker; a use case importing a concrete adapter is medium.
2. Crust integrity
External consumers use a slice's public seam in the language's native form —
exported identifiers in Go, the package __init__ surface in Python, an index
module in TypeScript, a public class surface elsewhere — never its internals.
from domains.pricing import calculate_discount is fine;
from domains.pricing.discount_calculator import ... is a violation —
high with multiple consumers, low with one.
3. Model purity
Domain files import only stdlib, common/, and sibling slice public APIs.
A domain file importing an HTTP client, ORM, or queue is a violation; the fix
is a port (protocol) defined in the domain and implemented by an adapter.
Grade severity from the doctrine:severity-cases matrix under
Severity below, in first-match order.
4. Growth justification
New directories and abstractions require demonstrated pressure. Two concrete uses are the normal evidence threshold, not a hard requirement. An abstract base with one implementation, an event bus interface when no event exists yet, or a registry with one plugin is medium only when no concrete pressure justifies it. "Numeric thresholds" in the guards below means the advisory growth signals (~200 lines, 3+ concepts, 3+ clustered files), not gradeable limits. Suppress these false positives:
- A single consumer does not by itself prove premature abstraction; grade whether concrete pressure exists. Two consumers are normal evidence, not a hard requirement.
- New single-file concepts that stayed single files are correct; do not flag them.
- A dispatcher introduced to break a cross-slice cycle is demonstrated pressure, even with one event and one subscriber.
- Numeric thresholds are advisory signals, not gradeable violations; grade implementation share, public-surface size, and lifetime mixing.
- In a language whose only privacy mechanism is file placement, a subdirectory marking its contents internal is demonstrated pressure for that visibility boundary, even with a single file inside.
| ID | Given | Expected | Rationale |
|---|---|---|---|
growth-cycle-event |
An event dispatcher is introduced to break a cross-slice cycle. | allow |
The dispatcher removes a concrete cycle and is a canonical exception to the pressure-first growth signal. |
growth-positional-one-file |
A one-file positional crust marks internal visibility in a language without another privacy mechanism. | allow |
The directory is a visibility boundary rather than speculative growth structure, even when it contains one file. |
growth-single-unpressured |
A new abstraction has one concrete consumer and no demonstrated pressure. | medium |
The normal two-concrete-consumer signal has not been met, so the abstraction should be challenged as premature rather than treated as a blocker. |
Apply the reference-owned doctrine:growth-cases matrix in first-match order; do not infer outcomes from prose outside the matrix.
5. Event usage
Events exist for reverse dependencies: B reacts to A without A knowing B.
Cycles between slices must resolve via events typed in common/, not mutual
imports (high).
Events used as general-purpose messaging where a direct import is the natural
dependency are a medium finding.
Severity
The severities cited in the checks above derive from this table.
| Severity | Meaning |
|---|---|
| blocker | Inverted dependency arrow; infrastructure executing at import time in a domain file |
| high | Cross-slice internal import; circular slice dependency; crust bypass with multiple consumers |
| medium | Model-purity drift (infrastructure imported, not executed at import time); premature abstraction; events-as-messaging; adapter imported outside the composition root |
| low | Single-consumer crust bypass; naming drift |
| ID | Given | Expected | Rationale |
|---|---|---|---|
severity-import-exec |
A domain module executes infrastructure work while it is imported. | blocker |
Import-time side effects make every consumer pay infrastructure cost and can fail before application startup is controlled. |
severity-static-domain-infra |
A domain model has a static dependency on infrastructure. | medium |
The dependency violates model purity and increases change coupling, but a static edge alone is not an import-time execution failure. |
severity-static-concrete-adapter |
A use case or application service imports a concrete adapter instead of a domain port. | medium |
The application layer is coupled to infrastructure selection; dependency injection through a port restores the intended boundary. |
severity-other-forbidden-edge |
A dependency edge points in a forbidden direction and does not match a more specific severity case. | blocker |
Unmatched structural inversions break the slice dependency contract and require immediate correction. |
Apply the reference-owned doctrine:severity-cases matrix in first-match order; do not infer outcomes from prose outside the matrix.
Output
Report findings grouped by severity, most severe first. Each finding:
severity — check — file:line — quoted evidence — one-line fix. An empty
report is a valid outcome; never manufacture findings. Do not fix anything —
this skill reviews only.