refactor(engine): extract shared slug + folder helpers into slug-utils

[dhruva-reddy]

Summary

Pure factoring PR. Consolidates duplicated helpers that accumulated across the gitops engine as symptom-fixes piled up. Zero behavior change at every reachable call site. Tier 1 of an engine consolidation series — surfaced by the post-mortem on the recanonicalize PR (#32, base of this stack).

What gets deduplicated

Helper	Before	After
`slugify`	4 byte-identical copies (`pull.ts`, `dep-dedup.ts`, `audit.ts`, `setup.ts`)	1 in `src/slug-utils.ts`
`extractBaseSlug`	2 byte-identical copies (`pull.ts`, `dep-dedup.ts`)	1
`FOLDER_MAP`	2 byte-identical copies (`pull.ts`, `resources.ts`)	1 in `resources.ts`
`UUID_SUFFIX_RE`	Open-coded in 3 places	1 constant
recanonicalize precondition-2 (UUID prefix match)	Inlined regex + comparison	Extracted as `isEngineSuffixedSlug`

Why a separate module instead of "just import from pull.ts"

`src/slug-utils.ts` is config-free by design — no `./config.ts` import, no side effects at load. `config.ts` asserts `argv[2]` / `VAPI_TOKEN` at module load and `process.exit(1)`s under unit tests. Any test that imports a slug helper transitively via `pull.ts` would otherwise have to prime `process.argv` and `process.env.VAPI_TOKEN` (see `tests/recanonicalize.test.ts:7-8`).

The prior `dep-dedup.ts` comment claimed its local duplicates were "intentionally copied for testability" but `new-file-gate.ts` imported the helper from `pull.ts` anyway — so the testability claim didn't actually hold. The new `slug-utils.ts` makes it real: zero imports, importable from any test without ceremony.

Two-form contract: loose vs. strict

The helpers split into two semantically distinct forms that callers were previously mixing:

• `extractBaseSlug(resourceId): string` — loose. Best-effort strip of an engine-shape suffix; returns input unchanged on no-match. Used by `audit.ts`, `new-file-gate.ts`, `pull.ts`, `dep-dedup.ts` where there's no UUID handy to verify against.
• `isEngineSuffixedSlug(stateKey, uuid): {base, suffix} | null` — strict. Returns the parts only when the captured 8-hex matches the UUID's first 8 hex chars. Used by `recanonicalize.ts` to PROVE a key was engine-generated (rules out user-named resources coincidentally ending in `-abcd1234`).

Regex tightening (intentional)

Shared `UUID_SUFFIX_RE` uses `^(.+)-([0-9a-f]{8})$` (non-empty base). Prior pull/dep-dedup copies used `^(.*)-...` (allowed empty base). Strict improvement:

• Engine-generated keys always have a non-empty base (`generateResourceId` produces `${slug}-${uuid8}` or `resource-${uuid8}`, both non-empty)
• The only input class affected is the synthetic `-<8hex>` shape
• Reachable call sites (`pull.ts:resourceIdMatchesName`, `audit.ts:checkSiblingBaseSlug`, `new-file-gate.ts:detectOrphanYamls`, `dep-dedup.ts:findExistingResourceByName`) all use `slugify(name)` upstream — `name` is non-empty by callsite guards, so `localSlug` is never `""`. Old behavior returned "no match"; new behavior returns "no match." No-op.
• Pinned by `tests/slug-utils.test.ts:57-62` regression test

Files changed

File	Change	LOC
`src/slug-utils.ts`	NEW (config-free utilities)	+77
`tests/slug-utils.test.ts`	NEW (20 cases)	+170
`src/pull.ts`	Delete `FOLDER_MAP`, `slugify`, `extractBaseSlug` locals; import from new modules	-30
`src/dep-dedup.ts`	Delete locals; import from `slug-utils`; re-export for back-compat	-29
`src/audit.ts`	Delete local `slugify`; re-route `extractBaseSlug` import	-12
`src/setup.ts`	Delete local `slugify`; import from `slug-utils`	-9
`src/new-file-gate.ts`	Re-route `extractBaseSlug` import (kept testability boundary clean)	+-7
`src/recanonicalize.ts`	Swap inlined precondition-2 check for `isEngineSuffixedSlug`	-16

Net: +275 / -85 → +190. New file weight is mostly the test suite (170 lines) — source-code net is +105 / -85 = +20.

Test plan

• `npm run build` (tsc --noEmit) — clean
• `npm test` — 228/228 pass (208 prior + 20 new)
• `npx @biomejs/biome check --write` — clean
• Byte-equivalence: 4 `slugify` copies + 2 `extractBaseSlug` copies verified byte-identical to the new shared definitions (modulo `export` keyword)
• Behavior preservation traced: every `extractBaseSlug` call site audited against the regex tightening — no observable change in realistic flows
• Testability boundary: `tests/slug-utils.test.ts` does NOT prime `process.argv` / `VAPI_TOKEN` — proves the module is config-free
• Back-compat: `dep-dedup.ts` re-exports `slugify` and `extractBaseSlug` so `tests/dep-dedup.test.ts` keeps importing via that path unchanged

Code review

In-branch review by code-reviewer subagent. No blocking findings. Four L-level cleanups addressed in-branch:

• L1: removed dead `extractBaseSlug` re-export in `pull.ts` (no consumers)
• L2: renamed stale "Slug helpers" section banner in `audit.ts` → "Resource name extraction"
• L3: updated `new-file-gate.ts` JSDoc reference from "pull.ts helper" → "slug-utils helper"
• L4: renamed `pull.ts` "Naming & Slug Generation" banner → "Resource naming" (slug generation moved out)

Stack

This is PR 1 of 2 in the engine-consolidation series. PR 2 stacks on this one and folds `ensureToolExists` / `ensureStructuredOutputExists` (both ~94 lines, structurally identical) into a generic `reconcileStateKeyForResource` helper. Reviewable alone — PR 2 is sequencing, not technical dependency.

Related

• VapiAI/gitops fix(push,pull): recanonicalize stale UUID-suffixed state keys — root-cause duplicate generation #32 (recanonicalize stale UUID-suffixed state keys — base of this stack)
• VapiAI/gitops fix: dedup dependency auto-apply to prevent duplicate tool mints (Gap #10) #23 (tool name-based dedup — symptomatic fix fix(gitops): restore 7 P0 regressions surfaced in feat/optimization-gitops-flow audit; add regression tests #10 in improvements.md, will be folded into the generic helper in PR 2)
• VapiAI/gitops feat(push): orphan-YAML gate — halt push when local files lack state entries #30 (orphan-YAML gate — uses `extractBaseSlug` for rename-source pairing)

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Note: this PR supersedes #33, which was auto-closed by GitHub when its base branch (the stack parent, now merged as #32) was deleted on merge.