chore: Replace Segment SDK Anonymous ID patch by plugin

[NicolasMassart]

What is this about?

The user ID sent in events depends on the event type: anonymous or not.
Current implementation patches Segment SDK to allow this behaviour.
A Segment SDK plugin can be used instead.

Scenario

No response

Design

No response

Technical Details

Replace the patch with a Segment SDK plugin
Create a custom plugin.

It makes it easier to maintain and allows to update the SDK with less risk.

Steps

1. Create a new file for the plugin: Create a new file, for example, MetaMaskPrivacyPlugin.ts.

2. Implement the plugin: Implement the plugin by extending the Segment SDK's Plugin class and overriding the necessary methods.

3. Register the plugin: Register the plugin with the Segment client.

Example implementation

Important

The following is untested code just to explain the idea.
It requires changes and testing (and unit testing)

Plugin file

MetaMetricsPrivacySegmentPlugin.ts

import { Plugin, SegmentEvent, EventType } from '@segment/analytics-react-native';

class MetaMetricsPrivacySegmentPlugin extends Plugin {
  configure(analytics) {
    this.analytics = analytics;
  }

  async execute(event: SegmentEvent): Promise<SegmentEvent> {
    // We only update id in track events, otherwise return event as is.
    if( event.type !== EventType.TrackEvent){
      return event;
    }

    const isAnonymousEvent = isTrackEvent && event.properties?.anonymous;

    delete event.properties?.anonymous;

    const hasProperties = event.properties && Object.entries(event.properties).length > 0;

    const userInfo = await this.analytics.userInfo.get(true);
    const userId = isAnonymousEvent && hasProperties ? userInfo.anonymousId : userInfo.userId ?? userInfo.anonymousId;

    return {
      ...event,
      userId,
    };
  }
}

export default MetaMaskPrivacyPlugin;

Register the plugin in app/core/Analytics/MetaMetrics.ts

const segmentClient = isE2E ? undefined : createClient(config);
segmentClient.add(new MetaMetricsPrivacySegmentPlugin());

Threat Modeling Framework

No response

Acceptance Criteria

No response

Stakeholder review needed before the work gets merged

• Engineering (needed in most cases)
• Design
• Product
• QA (automation tests are required to pass before merging PRs but not all changes are covered by automation tests - please review if QA is needed beyond automation tests)
• Security
• Legal
• Marketing
• Management (please specify)
• Other (please specify)

References

https://segment.com/docs/connections/sources/catalog/libraries/mobile/react-native/#writing-your-own-plugins