Add preliminary message backup harness

ts/test-mock/backups/backups_test.ts

@@ -0,0 +1,116 @@
+// Copyright 2023 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+
+import createDebug from 'debug';
+import Long from 'long';
+
+import * as durations from '../../util/durations';
+import type { App } from '../playwright';
+import { Bootstrap } from '../bootstrap';
+
+export const debug = createDebug('mock:test:backups');
+
+describe('backups', function (this: Mocha.Suite) {
+  this.timeout(100 * durations.MINUTE);
+
+  let bootstrap: Bootstrap;
+  let app: App;
+
+  beforeEach(async () => {
+    bootstrap = new Bootstrap();
+    await bootstrap.init();
+    app = await bootstrap.link();
+  });
+
+  afterEach(async function (this: Mocha.Context) {
+    if (!bootstrap) {
+      return;
+    }
+
+    await bootstrap.maybeSaveLogs(this.currentTest, app);
+    await app.close();
+    await bootstrap.teardown();
+  });
+
+  it('exports and imports backup', async function () {
+    const { contacts, phone, desktop, server } = bootstrap;
+    const [friend] = contacts;
+
+    for (let i = 0; i < 5; i += 1) {
+      const theirTimestamp = bootstrap.getTimestamp();
+
+      // eslint-disable-next-line no-await-in-loop
+      await friend.sendText(desktop, `msg ${i}`, {
+        timestamp: theirTimestamp,
+      });
+
+      const ourTimestamp = bootstrap.getTimestamp();
+
+      // eslint-disable-next-line no-await-in-loop
+      await server.send(
+        desktop,
+        // eslint-disable-next-line no-await-in-loop
+        await phone.encryptSyncSent(desktop, `respond ${i}`, {
+          timestamp: ourTimestamp,
+          destinationServiceId: friend.device.aci,
+        })
+      );
+
+      const reactionTimestamp = bootstrap.getTimestamp();
+
+      // eslint-disable-next-line no-await-in-loop
+      await friend.sendRaw(
+        desktop,
+        {
+          dataMessage: {
+            timestamp: Long.fromNumber(reactionTimestamp),
+            reaction: {
+              emoji: '👍',
+              targetAuthorAci: desktop.aci,
+              targetTimestamp: Long.fromNumber(ourTimestamp),
+            },
+          },
+        },
+        {
+          timestamp: reactionTimestamp,
+        }
+      );
+    }
+
+    const comparator = await bootstrap.createScreenshotComparator(
+      app,
+      async (window, snapshot) => {
+        const leftPane = window.locator('#LeftPane');
+        const contactElem = leftPane.locator(
+          `[data-testid="${friend.toContact().aci}"] >> "respond 4"`
+        );
+
+        debug('Waiting for messages to come through');
+        await contactElem.waitFor();
+
+        await snapshot('main screen');
+
+        debug('Going into the conversation');
+        await contactElem.click();
+        await window
+          .locator('.ConversationView .module-message >> "respond 4"')
+          .waitFor();
+
+        await snapshot('conversation');
+      },
+      this.test
+    );
+
+    const backupPath = bootstrap.getBackupPath('backup.bin');
+    await app.exportBackupToDisk(backupPath);
+    await app.close();
+
+    // Restart
+    await bootstrap.unlink();
+    app = await bootstrap.link({
+      ciBackupPath: backupPath,
+    });
+
+    await comparator(app);
+  });
+});