feat(blog): add createArticleUseCase (test red until DI + mock repo exist)

packages/blog/src/application/use-cases/create-article.use-case.test.ts

@@ -0,0 +1,45 @@
+import { beforeEach, describe, expect, it } from "vitest";
+import { blogContainer } from "@/di/container";
+import { BLOG_SYMBOLS } from "@/di/symbols";
+import type { IArticlesRepository } from "@/application/repositories/articles-repository.interface";
+import { MockArticlesRepository } from "@/infrastructure/repositories/mock-articles.repository";
+import { createArticleUseCase } from "./create-article.use-case";
+
+describe("createArticleUseCase", () => {
+  let repo: MockArticlesRepository;
+
+  beforeEach(() => {
+    if (blogContainer.isBound(BLOG_SYMBOLS.IArticlesRepository)) {
+      blogContainer.unbind(BLOG_SYMBOLS.IArticlesRepository);
+    }
+    repo = new MockArticlesRepository();
+    blogContainer
+      .bind<IArticlesRepository>(BLOG_SYMBOLS.IArticlesRepository)
+      .toConstantValue(repo);
+  });
+
+  it("creates an article in draft status with auto-generated slug", async () => {
+    const result = await createArticleUseCase({
+      title: "Hello World",
+      content: "body",
+      authorId: "u1",
+    });
+    expect(result.title).toBe("Hello World");
+    expect(result.slug).toBe("hello-world");
+    expect(result.status).toBe("draft");
+    expect(result.id).toBeTruthy();
+
+    const stored = await repo.getArticle(result.id);
+    expect(stored).toBeDefined();
+  });
+
+  it("uses provided slug when supplied", async () => {
+    const result = await createArticleUseCase({
+      title: "Whatever",
+      content: "body",
+      authorId: "u1",
+      slug: "custom-slug",
+    });
+    expect(result.slug).toBe("custom-slug");
+  });
+});

packages/blog/src/application/use-cases/create-article.use-case.ts

@@ -0,0 +1,36 @@
+import type { Article } from "@/entities/article";
+import { blogContainer } from "@/di/container";
+import { BLOG_SYMBOLS } from "@/di/symbols";
+import type { IArticlesRepository } from "@/application/repositories/articles-repository.interface";
+
+function generateSlug(title: string): string {
+  return title
+    .toLowerCase()
+    .replace(/[^a-z0-9]+/g, "-")
+    .replace(/^-+|-+$/g, "");
+}
+
+export async function createArticleUseCase(input: {
+  title: string;
+  content: unknown;
+  authorId: string;
+  slug?: string;
+}): Promise<Article> {
+  const repo = blogContainer.get<IArticlesRepository>(
+    BLOG_SYMBOLS.IArticlesRepository,
+  );
+
+  const now = new Date();
+  const article: Article = {
+    id: crypto.randomUUID(),
+    title: input.title,
+    slug: input.slug ?? generateSlug(input.title),
+    content: input.content,
+    status: "draft",
+    authorId: input.authorId,
+    createdAt: now,
+    updatedAt: now,
+  };
+
+  return repo.createArticle(article);
+}