feat(core-eslint): use-case name helper (file slug → manifest key)

packages/core-eslint/rules/_usecase-name.test.js

@@ -0,0 +1,19 @@
+import { describe, it, expect } from "vitest";
+import { useCaseNameFromFile } from "./_usecase-name.js";
+
+describe("useCaseNameFromFile", () => {
+  it("converts kebab-case slug to camelCase", () => {
+    expect(useCaseNameFromFile("/repo/packages/auth/src/application/use-cases/sign-in.use-case.ts")).toBe("signIn");
+    expect(useCaseNameFromFile("/repo/packages/auth/src/application/use-cases/sign-up.use-case.ts")).toBe("signUp");
+    expect(useCaseNameFromFile("/repo/packages/blog/src/application/use-cases/get-article-by-slug.use-case.ts")).toBe("getArticleBySlug");
+  });
+
+  it("handles single-word slugs", () => {
+    expect(useCaseNameFromFile("/repo/packages/x/src/application/use-cases/login.use-case.ts")).toBe("login");
+  });
+
+  it("returns null for non-use-case files", () => {
+    expect(useCaseNameFromFile("/repo/packages/auth/src/index.ts")).toBeNull();
+    expect(useCaseNameFromFile("/repo/packages/auth/src/feature.manifest.ts")).toBeNull();
+  });
+});