---
id: 03-a-structural-eslint-rules
epic: conformance-system-v1
title: Structural ESLint rules (feature-must-have-manifest, usecase-must-have-test-file, required-cores-installed)
type: technical-story
status: done
feature: core-eslint
depends-on: [02-boot-assertions]
blocks: [03-b-ast-aware-eslint-rules]
---

## Goal
Stand up the custom ESLint rule plugin in `@repo/core-eslint` and ship three
structural conformance rules that don't require cross-file AST analysis.
Editor + CLI feedback fires in <1s.

## Why
Boot-time assertion catches drift in bound use cases, but cannot catch:
- Features that exist on disk but have no manifest at all
- Use-case files lacking a sibling test file
- Manifest declaring required cores that aren't in `pnpm-workspace.yaml`

Structural ESLint rules surface these in the editor, before code is even
saved past lint-on-save.

## Done when
- Custom rule plugin exists at `packages/core-eslint/plugin.js`
- Three rules registered: `conformance/feature-must-have-manifest`,
  `conformance/usecase-must-have-test-file`,
  `conformance/required-cores-installed`
- Each rule has RuleTester tests with positive + negative cases
- `base.js` registers the plugin and enables the rules
- `pnpm lint` passes for the current monorepo state (rules tuned to today's
  reality — see Out of scope)

## In scope
- Custom rule plugin module at `packages/core-eslint/plugin.js`
- Rule modules in `packages/core-eslint/rules/*.js`
- Manifest text parser (`_manifest-source.js`) — regex-based, sufficient for
  literal `as const` manifests
- Workspace.yaml reader (`_workspace.js`)
- Rule integration into `base.js`
- Tests for each rule using ESLint's RuleTester

## Out of scope
- Cross-file AST analysis rules (`no-undeclared-event-publish`,
  `no-undeclared-audit`) — milestone iii.b
- Enforcement on features that don't yet have a manifest — `feature-must-have-manifest`
  ships as a WARNING today (only auth has a manifest); flips to ERROR after
  blog/media/navigation/marketing-pages get manifests
- Manifest parser based on TypeScript compiler API — regex is sufficient for
  literal manifests; the AST path comes in iii.b

## Tasks
- [x] Story 03.a scaffold
- [x] Manifest source helper (`_manifest-source.js`)
- [x] Workspace helper (`_workspace.js`)
- [x] `feature-must-have-manifest` rule + tests
- [x] `usecase-must-have-test-file` rule + tests
- [x] `required-cores-installed` rule + tests
- [x] Plugin module + `exports` entry in `package.json`
- [x] Wire plugin into `base.js`
- [x] Verify `pnpm lint` passes against the monorepo
- [x] Final verification + story closeout