Test & Debug - React Native SDK

Clean Up Tests

When testing the Realm React Native SDK, you must close realms with Realm.close() after you're done with them to prevent memory leaks.

You should also delete the realm file with Realm.deleteFile() during clean up to keep your tests idempotent.

The below example uses the Jest testing framework. It uses Jest's built-in beforeEach() and afterEach() hooks for test set up and tear down, respectively.

const config = {
  schema: [Car],
};
let realm;
beforeEach(async () => {
  realm = await Realm.open(config);
});
afterEach(() => {
  if (!realm.isClosed) {
    realm.close();
  }
  if (config) {
    Realm.deleteFile(config);
  }
});
test("Close a Realm", async () => {
  expect(realm.isClosed).toBe(false);
  realm.close();
  expect(realm.isClosed).toBe(true);
});

Safari Developer Tools

If you're a macOS user, you can use Safari Developer Tools to debug the iOS version of your React Native app with Realm.

To set up Safari Developer Tools with your React Native app, refer to the official documentation.

Flipper

Flipper is a platform for debugging React Native apps. You can currently only only use Flipper with the Realm React Native SDK Hermes release. Hermes is a JavaScript engine optimized for React Native.

Chrome Developer Tools

While Realm works with the Chrome Developer Tools on React Native, the debugger's performance degrades significantly when using it with Realm. This is due to the blocking nature of the RPC calls made by Realm.

If you are able, you should use the Safari Developer Tools or Flipper instead of the Chrome Developer Tools.