Compute provisioning URL in separate function

ts/test-both/util/getProvisioningUrl_test.ts

@@ -0,0 +1,23 @@
+// Copyright 2021 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+
+import { assert } from 'chai';
+import { size } from '../../util/iterables';
+
+import { getProvisioningUrl } from '../../util/getProvisioningUrl';
+
+describe('getProvisioningUrl', () => {
+  it('returns a URL with a UUID and public key', () => {
+    const uuid = 'a08bf1fd-1799-427f-a551-70af747e3956';
+    const publicKey = new Uint8Array([9, 8, 7, 6, 5, 4, 3]);
+
+    const result = getProvisioningUrl(uuid, publicKey);
+    const resultUrl = new URL(result);
+
+    assert(result.startsWith('tsdevice:/?'));
+    assert.strictEqual(resultUrl.protocol, 'tsdevice:');
+    assert.strictEqual(size(resultUrl.searchParams.entries()), 2);
+    assert.strictEqual(resultUrl.searchParams.get('uuid'), uuid);
+    assert.strictEqual(resultUrl.searchParams.get('pub_key'), 'CQgHBgUEAw==');
+  });
+});