Two-axis review of the diff between HEAD and a fixed point the user supplies:
- Standards: does the code conform to this repo's documented coding standards?
- Spec: does the code faithfully implement the originating issue / spec?
Both axes run as parallel sub-agents so they don't pollute each other's context, then this skill aggregates their findings.
The issue tracker should have been provided to you. If not, tell the user to run /setup-matt-pocock-skills.
Process
1. Pin the fixed point
Whatever the user said is the fixed point (a commit SHA, branch name, tag, main, HEAD~5, etc.). If they didn't specify one, ask for it.
Capture the diff command once: git diff <fixed-point>...HEAD (three-dot, so the comparison is against the merge-base). Also note the list of commits via git log <fixed-point>..HEAD --oneline.
Before going further, confirm the fixed point resolves (git rev-parse <fixed-point>) and the diff is non-empty. A bad ref 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:
- Issue references in the commit messages (
#123,Closes #45, GitLab!67, etc.), fetched via the workflow in the tracker doc. - A path the user passed as an argument.
- A spec file under
docs/,specs/, or.scratch/matching the branch name or feature. - If nothing is found, ask the user where the spec is. If they say there isn't one, the Spec sub-agent will skip and report "no spec available".
3. Identify the standards sources
Search the repo for every file that documents how code should be written. When CODING_STANDARDS.md or CONTRIBUTING.md exists, it must be on the list.
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. 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
Issue both sub-agent calls together, in the foreground, and aggregate the reports they return.
Standards sub-agent prompt should include:
- The full diff command and 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 should include:
- The diff command and 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, because 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.