Timeline: repair oldest/newest metrics if we fetch nothing

ts/test-node/updater/curve_test.ts

@@ -0,0 +1,17 @@
+// Copyright 2019-2020 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+
+import { assert } from 'chai';
+
+import { keyPair, sign, verify } from '../../updater/curve';
+
+describe('updater/curve', () => {
+  it('roundtrips', () => {
+    const message = Buffer.from('message');
+    const { publicKey, privateKey } = keyPair();
+    const signature = sign(privateKey, message);
+    const verified = verify(publicKey, message, signature);
+
+    assert.strictEqual(verified, true);
+  });
+});