Harden CMS security and theme contrast

src/lib/auth/session-user.test.ts

@@ -0,0 +1,28 @@
+import { describe, expect, it } from "vitest";
+import { databaseUserId, sessionUserId } from "@/lib/auth/session-user";
+
+describe("sessionUserId", () => {
+  it("returns a positive safe integer from a valid session id", () => {
+    expect(sessionUserId("42")).toBe(42);
+  });
+
+  it.each([undefined, null, "", "0", "-1", "1.5", "abc", Number.MAX_SAFE_INTEGER + 1])(
+    "rejects invalid session id %s",
+    (value) => {
+      expect(sessionUserId(value)).toBeNull();
+    },
+  );
+});
+
+describe("databaseUserId", () => {
+  it("converts a safe positive database id", () => {
+    expect(databaseUserId(42n)).toBe(42);
+  });
+
+  it.each([0n, -1n, BigInt(Number.MAX_SAFE_INTEGER) + 1n])(
+    "rejects unsafe database id %s",
+    (value) => {
+      expect(databaseUserId(value)).toBeNull();
+    },
+  );
+});