code-review

name	code-review
description	Review changes since a fixed point along two axes — Standards (does the code follow this repo's documented coding standards?) and Spec (does the code match the originating shape, revision description, issue, or PRD?). Runs both reviews in parallel sub-agents and reports them side by side. Use when the user wants to review a branch, revision, PR, working-copy changes, or asks to "review since X".

Two-axis review of the diff between the working revision and a fixed point:

• Standards — does the code conform to this repo's documented coding standards?
• Spec — does the code faithfully implement the originating shape, revision description, issue, PRD, or approved chat proposal?

Both axes run as parallel sub-agents so they don't pollute each other's context, then this skill aggregates their findings.

Process

1. Pin the fixed point

Whatever the user said is the fixed point — a jj revision, commit SHA, branch/bookmark name, tag, main, HEAD~5, etc. If they didn't specify one, ask for it.

Detect the repository's VCS. Prefer jj when .jj/ is present; otherwise use Git.

In jj, call the current @ diff working-copy changes. Never call changes staged or unstaged: jj has no staging area, and its working copy is itself a commit.

• jj: capture jj diff --from <fixed-point> --to @ and the changed revisions via jj log -r '<fixed-point>::@'.
• Git: capture git diff <fixed-point>...HEAD (three-dot, so the comparison is against the merge-base) and the commits via git log <fixed-point>..HEAD --oneline.

Before going further, confirm the fixed point resolves and the diff is non-empty. A bad revision or empty diff should fail here — not inside two parallel sub-agents.

2. Identify the spec source

Look for the originating spec, in this order:

1. A path or source the user explicitly supplied.
2. In a jj repo, the descriptions of the changed revisions. Treat a loose revision description as a shaped spec: extract its stated problem, intent, constraints, and acceptance cues without demanding formal requirements. When several descriptions contribute, preserve which revision supplied each expectation.
3. The current conversation. If the user approved a substantive proposal with a short acknowledgement such as "yea this looks good", treat the immediately preceding proposal or plan as the spec. The acknowledgement itself is evidence of approval, not the spec content. Do not search unrelated or older chats unless the user points to them.
4. Issue references in revision or commit descriptions (#123, Closes #45, GitLab !67, etc.). Fetch them with the available issue-tracker integration or CLI.
5. A PRD/spec file under docs/, specs/, or .scratch/ matching the bookmark, branch, or feature.
6. If nothing is found, ask the user where the spec is. If they say there isn't one, skip the Spec sub-agent and report "no spec available".

The spec may be intentionally loose. Judge the implementation against what the shape actually commits to; do not invent requirements to make it look formal. Record ambiguities as ambiguities rather than failures.

3. Identify the standards sources

Anything in the repo that documents how code should be written, such as CODING_STANDARDS.md or CONTRIBUTING.md.

On top of whatever the repo documents, the Standards axis always carries the smell baseline below — a fixed set of Fowler code smells (Refactoring, ch.3) that applies even when a repo documents nothing. Two rules bind it:

• The repo overrides. A documented repo standard always wins; where it endorses something the baseline would flag, suppress the smell.
• Always a judgement call. Each smell is a labelled heuristic ("possible Feature Envy"), never a hard violation — and, like any standard here, skip anything tooling already enforces.

Each smell reads what it is → how to fix; match it against the diff:

• Mysterious Name — a function, variable, or type whose name doesn't reveal what it does or holds. → rename it; if no honest name comes, the design's murky.
• Duplicated Code — the same logic shape appears in more than one hunk or file in the change. → extract the shared shape, call it from both.
• Feature Envy — a method that reaches into another object's data more than its own. → move the method onto the data it envies.
• Data Clumps — the same few fields or params keep travelling together (a type wanting to be born). → bundle them into one type, pass that.
• Primitive Obsession — a primitive or string standing in for a domain concept that deserves its own type. → give the concept its own small type.
• Repeated Switches — the same switch/if-cascade on the same type recurs across the change. → replace with polymorphism, or one map both sites share.
• Shotgun Surgery — one logical change forces scattered edits across many files in the diff. → gather what changes together into one module.
• Divergent Change — one file or module is edited for several unrelated reasons. → split so each module changes for one reason.
• Speculative Generality — abstraction, parameters, or hooks added for needs the spec doesn't have. → delete it; inline back until a real need shows.
• Message Chains — long a.b().c().d() navigation the caller shouldn't depend on. → hide the walk behind one method on the first object.
• Middle Man — a class or function that mostly just delegates onward. → cut it, call the real target direct.
• Refused Bequest — a subclass or implementer that ignores or overrides most of what it inherits. → drop the inheritance, use composition.

4. Spawn both sub-agents in parallel

Use the host's sub-agent mechanism to start both reviewers concurrently. Use general-purpose agents and give each only the context for its axis. Do not run one review after the other or let either agent see the other report.

Standards sub-agent prompt — include:

• The full diff command and revision/commit list.
• The list of standards-source files you found in step 3, plus the smell baseline from step 3 pasted in full — the sub-agent has no other access to it.
• The brief: "Report — per file/hunk where relevant — (a) every place the diff violates a documented standard: cite the standard (file + the rule); and (b) any baseline smell you spot: name it and quote the hunk. Distinguish hard violations from judgement calls — documented-standard breaches can be hard, but baseline smells are always judgement calls, and a documented repo standard overrides the baseline. Skip anything tooling enforces. Under 400 words."

Spec sub-agent prompt — include:

• The diff command and revision/commit list.
• The path or fetched contents of the spec.
• The brief: "Report: (a) requirements the spec asked for that are missing or partial; (b) behaviour in the diff that wasn't asked for (scope creep); (c) requirements that look implemented but where the implementation looks wrong. Quote the spec line for each finding. Under 400 words."

If the spec is missing, skip the Spec sub-agent and note this in the final report.

5. Aggregate

Present the two reports under ## Standards and ## Spec headings, verbatim or lightly cleaned. Do not merge or rerank findings — the two axes are deliberately separate (see Why two axes).

End with a one-line summary: total findings per axis, and the worst issue within each axis (if any). Don't pick a single winner across axes — that's the reranking the separation exists to prevent.

Why two axes

A change can pass one axis and fail the other:

• Code that follows every standard but implements the wrong thing → Standards pass, Spec fail.
• Code that does exactly what the issue asked but breaks the project's conventions → Spec pass, Standards fail.

Reporting them separately stops one axis from masking the other.