Add paid-access and usage limit helpers for clean-pdf

src/lib/clean-pdf/__tests__/access.test.ts

@@ -0,0 +1,43 @@
+import { describe, expect, it } from "vitest";
+import { decidePaidAccess, monthStartUtc } from "@/lib/clean-pdf/access";
+
+const now = new Date("2026-07-06T10:00:00Z");
+const freeSlug = "obsidian-start";
+
+describe("decidePaidAccess", () => {
+  it("платный enrollment без срока — да", () => {
+    expect(decidePaidAccess({ role: "student", banned: false, freeSlug, now,
+      enrollments: [{ courseSlug: "zotero", expiresAt: null }] })).toBe(true);
+  });
+
+  it("только бесплатный курс — нет", () => {
+    expect(decidePaidAccess({ role: "student", banned: false, freeSlug, now,
+      enrollments: [{ courseSlug: "obsidian-start", expiresAt: null }] })).toBe(false);
+  });
+
+  it("без enrollments — нет", () => {
+    expect(decidePaidAccess({ role: "student", banned: false, freeSlug, now, enrollments: [] })).toBe(false);
+  });
+
+  it("истёкший платный — нет, живой срок — да", () => {
+    expect(decidePaidAccess({ role: "student", banned: false, freeSlug, now,
+      enrollments: [{ courseSlug: "zotero", expiresAt: new Date("2026-01-01") }] })).toBe(false);
+    expect(decidePaidAccess({ role: "student", banned: false, freeSlug, now,
+      enrollments: [{ courseSlug: "zotero", expiresAt: new Date("2027-01-01") }] })).toBe(true);
+  });
+
+  it("admin и curator — да даже без курсов", () => {
+    expect(decidePaidAccess({ role: "admin", banned: false, freeSlug, now, enrollments: [] })).toBe(true);
+    expect(decidePaidAccess({ role: "curator", banned: false, freeSlug, now, enrollments: [] })).toBe(true);
+  });
+
+  it("бан всё перекрывает", () => {
+    expect(decidePaidAccess({ role: "admin", banned: true, freeSlug, now, enrollments: [] })).toBe(false);
+  });
+});
+
+describe("monthStartUtc", () => {
+  it("возвращает первое число месяца 00:00 UTC", () => {
+    expect(monthStartUtc(new Date("2026-07-06T23:59:59Z")).toISOString()).toBe("2026-07-01T00:00:00.000Z");
+  });
+});