# AGENTS.md — blog

Articles collection + content use cases (get article, list articles, create, publish, unpublish). Provides the Articles Payload collection and tRPC procedures for content management and retrieval.

## What it owns

- **Entities** — Article type, article-related errors (ArticleNotFound, InvalidSlug)
- **Use cases** — Get article, list articles, create, publish, unpublish, delete
- **Repository interface** — `IArticlesRepository` for article persistence
- **Mock repository** — In-memory article store for tests
- **Payload repository** — Real Payload-backed article repository (constructor-injected at boot)
- **Payload collection** — Articles collection definition + hooks (publish timestamp, slugify)
- **tRPC router** — Procedures for list, get-by-slug, create, publish
- **DI container** — Per-feature InversifyJS container with blog symbols
- **UI components** — Article-specific components (ArticleCard, ArticleList, etc.)

## Public exports

From `package.json`:
- `.` — Article type + blog errors + UI components
- `./api` — tRPC router (`blogRouter`)
- `./cms` — Payload Articles collection
- `./di/bind-production` — `bindProductionArticles()` to wire Payload repo at boot

## What it must NOT import

- Any other feature package (`@repo/auth`, `@repo/media`, etc.)
- Any app package
- `@repo/core-api`, `@repo/core-cms`, `@repo/core-trpc`, `@repo/core-ui` directly; only import from `@repo/core-shared` and use DI for Payload config

## Layer rules

### `src/` files use relative imports

Avoid `@/` in source code:

```typescript
// ✓ Correct
import type { IArticlesRepository } from "../repositories/articles.repository.interface.js";

// ✗ Wrong (don't do this in src/)
import { Article } from "@/entities/article.js";
```

### Tests use @/ alias

Test files use `@/`:

```typescript
// ✓ Correct
import { getArticleUseCase } from "@/application/use-cases/get-article.use-case.js";
```

### DI container is per-feature

Tests rebind their own container:

```typescript
import { container as blogContainer, BLOG_SYMBOLS } from "@/di/container.js";
import { MockArticlesRepository } from "@/infrastructure/repositories/mock-articles.repository.js";

beforeEach(() => {
  blogContainer.unbindAll();
  blogContainer.bind(BLOG_SYMBOLS.IArticlesRepository).to(MockArticlesRepository);
});
```

## Test conventions

- **Unit tests** colocated with source: `*.test.ts` suffix
- **Feature tests** in `tests/` folder: `*.feature.test.ts` suffix (cross-layer tests like publish flow)
- **Vitest environment** — `node`
- **Alias** — `@/` resolves to `src/`
- **Run** — `pnpm test --filter @repo/blog`

Covered areas: article CRUD use cases, slug validation, publish/unpublish flows, DI container binding.

## Tests

- **Factories:** `src/__factories__/article.factory.ts` — use `articleFactory.build({ overrides })` to construct test data with stable defaults.
- **Contract suite:** `src/__contracts__/articles-repository.contract.ts` — runs against every repository implementation (mock + payload).
- **Unit tests:** colocated as `*.test.ts` next to the source file.
- **Feature integration:** `tests/articles.feature.test.ts` — full slice through tRPC router → controller → use case → mock repo.

```bash
pnpm test --filter @repo/blog           # all tests for this feature
pnpm test --filter @repo/blog -- --watch # watch mode
```

See `docs/guides/tdd-workflow.md` for the cycle.

## Structure

```
src/
  entities/
    article.ts               # Article schema + type
    errors.ts                # ArticleNotFound, InvalidSlug, etc.
  application/
    repositories/
      articles.repository.interface.ts
    use-cases/
      get-article.use-case.ts
      list-articles.use-case.ts
      publish-article.use-case.ts
  infrastructure/
    repositories/
      payload-articles.repository.ts   # constructor-injected: Config
      mock-articles.repository.ts
  di/
    symbols.ts               # BLOG_SYMBOLS
    container.ts             # blogContainer
    bind-production.ts       # bindProductionArticles(container, config)
  interface-adapters/
    controllers/
      articles.controller.ts # input validation
  integrations/
    cms/
      collections/
        articles.ts          # Payload CollectionConfig
      hooks/
        after-publish.ts     # revalidate, effects
      index.ts
    api/
      router.ts              # tRPC procedures
      index.ts
  ui/
    article-card.tsx
    article-list.tsx
    query.ts                 # typed tRPC query helpers
  index.ts                   # re-exports: Article, UI components
tests/
  publish-article.feature.test.ts
```