CARD: scaffold-i-codemods — Scaffolded Edit Operations / Codemods (Go)

Band 1 — Identity & Recognition

02Classification: layer=H (weak-reader) + A (language-shape); mechanism=scaffold I.

03Intent: Offer a capability-demanding multi-file change as ONE parameterized, checked operation — converting an edit a weak agent cannot safely coordinate into a parameter-filling task. Go's tooling sits mid-way between Rust's (immature) and TypeScript's (rich): gofmt -r ships pattern rewrites in the toolchain itself; go/ast + go/format make structural codemods a stdlib exercise; golang.org/x/tools/go/analysis offers the framework tier.

04Also Known As: codemod; AST rewrite; gofmt -r; refactoring script; scripted migration; analysis-with-fix.

05Applicability / Recognition: Apply when — a common change touches many files atomically (add a cell, register a variant, rename across a seam); the edit's size is itself the failure driver (R2C-006); the weakest swarm tier cannot coordinate it by hand. Detector seed: a recurring change-type that reliably requires touching >1 file in lockstep → recognition fires.

Band 2 — Justification & Tradeoffs

06Motivation: A weak agent asked to "add a planner variant" must create the cell package, the conformance assertion, the directive tags, the registry arm, and the Example stub — five artefacts in lockstep. go-ai-native codemod add-cell --cell <cell> --spec-uri <uri> collapses the scaffolding half into two parameters: it writes doc.go with its //spec:scope directive, the cell source with its New constructor, and a smoke test carrying an executed Example — atomically, post-checked by the new package's own go test, rolled back on failure. The seam-conformance assertion and the registry arm stay the author's. This mirrors how constrained decoding lifts weak models (DR1-015): collapse the hard task into a constrained, parameterized one.

07Structure & Participants: Codemod (gofmt -r for pattern rewrites; a go/ast+go/format program or the shipped CLI verb for structural ones) · Parameters (the small named inputs) · Atomic application (all-or-nothing) · Post-check (go build + per-package go test green).

08Collaborations: Implements bulk application of Classes A/B/G in raids; emits Class F diagnostics on failure; the Class D oracle wraps it when it changes behavior.

09Goals / Non-Goals: Goals: convert capability-demanding multi-file edits into parameterized operations for the weak swarm. Non-Goals: NOT a general refactoring IDE; NOT for one-off changes; NOT semantic transforms without a Class-D wrap.

10Consequences: (+) the weakest tier can perform edits otherwise beyond it; (+) atomicity kills desync and phantom diffs; (+) gofmt -r gives the simplest rewrites for free, and go/format output is canonical by construction (no formatting drift). (−) codemods are code to maintain and test; (−) [E-hyp] risk: parameterizing a codemod may itself exceed the weakest models — the very build/use boundary in question.

11Alternatives: hand-editing (fails at scale for weak agents); a generator (Class A) when the artifact is derivable rather than transformed. Codemods are for TRANSFORMING existing code.

12Risks & Assumptions: assumes weak agents can correctly parameterize the operation — UNVALIDATED; this is the prime pilot question. If false, restrict the weakest tier to fixed-parameter invocations only. Go's tooling maturity removes the build-side risk for simple rewrites (gofmt -r is toolchain-native); complex semantic codemods remain authored one-offs. Sunset: if language/tooling makes the change trivial, the codemod retires.

13Evidence & Transfer-strength: first-principles from R3-013 (ownership graph bounds throughput) + R2C-006 (edit size drives failure) + DR1-015 (constraints lift weak models). Class: theory. Tag: [E-hyp].

Band 3 — Operation

trigger: WHEN a recurring change-type reliably requires >1 file edited in lockstep THEN apply
mode: raid            # bulk application; also offered as an on-demand command
routine:
  1. Identify the recurring multi-file change and its minimal parameters.
  2. Prefer `gofmt -r 'old -> new'` where the change is a pure expression rewrite; else implement a go/ast + go/format codemod (or use the shipped `go-ai-native codemod add-cell`).
  3. Add a post-check: result builds (`go build ./...`) and the touched packages' tests pass.
  4. Wrap behavior-changing codemods in a Class-D oracle.
  5. For the weakest tier, expose ONLY fixed-parameter invocations until the pilot validates free parameterization.
checker: the codemod's own post-check (go build + go test) ; conform `multi-file-change-has-codemod` (advisory, WISH until pilot-validated)
raid_role: layer=any; order=wraps-with:differential-oracle; batch=package
budget: active_rules=1; first_signal=codemod post-check (<60s/package)