metametrics tracks too many events

What is this about?

MetaMetrics trackEvents sends too many events in some cases.

It's like it's doing both anonymous and non anonymous tracking at the same time, resulting in 3 events instead of 1.

Example:

Onboaring phase: when not checking marketing checkbox

 INFO  TRACK event saved {"event": "Terms of Use Shown", "properties": {}, "type": "track"}
 INFO  IDENTIFY event saved {"traits": {"Batch account balance requests": "ON", "Enable OpenSea API": "ON", "NFT Autodetection": "OFF", "Theme": "light", "applicationVersion": "7.23.0", "currentBuildNumber": "1333", "deviceBrand": "Apple", "is_metrics_opted_in": true, "operatingSystemVersion": "17.5", "platform": "ios", "security_providers": "blockaid", "token_detection_enable": "ON"}, "type": "identify", "userId": "19f4001c-68a6-4b62-9f1d-d8f6ff92718e"}
 INFO  TRACK event saved {"event": "Wallet Setup Started", "properties": {}, "type": "track"}
 INFO  TRACK event saved {"event": "Analytics Preference Selected", "properties": {"is_metrics_opted_in": true, "location": "onboarding_metametrics", "updated_after_onboarding": false}, "type": "track"}
 INFO  TRACK event saved {"event": "Analytics Preference Selected", "properties": {"is_metrics_opted_in": true, "location": "onboarding_metametrics", "updated_after_onboarding": false}, "type": "track"}
 INFO  TRACK event saved {"event": "Analytics Preference Selected", "properties": {}, "type": "track"}
 INFO  TRACK event saved {"event": "Welcome Message Viewed", "properties": {}, "type": "track"}
 INFO  TRACK event saved {"event": "Onboarding Started", "properties": {}, "type": "track"}
 INFO  Sent 1 events
 INFO  Sent 7 events

We should not have so many "Analytics Preference Selected" events, 1 and 2 seems to be an anonymous and a non-anonymous events (not sure of the order, 1 and 2 may be reverted).

But if we consider they are in the right order, in the following, event 2 is wrong and should not exist as the event was sent using trackEvent and not trackAnonymousEvent. See app/components/UI/OptinMetrics/index.js onConfirm()

1: this is an anonymous event (UUID Zero), properly not showing in user events

 INFO  TRACK event saved {"event": "Analytics Preference Selected", "properties": {"is_metrics_opted_in": true, "location": "onboarding_metametrics", "updated_after_onboarding": false}, "type": "track"}

2: event with props, should be anonymous (UUID Zero) but it's not, showing up in user (see screenshot first event)

 INFO  TRACK event saved {"event": "Analytics Preference Selected", "properties": {"is_metrics_opted_in": true, "location": "onboarding_metametrics", "updated_after_onboarding": false}, "type": "track"}

3: anonymous event (no props), see second event in screenshot

 INFO  TRACK event saved {"event": "Analytics Preference Selected", "properties": {}, "type": "track"}

Scenario

No response

Design

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Technical Details

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Threat Modeling Framework

No response

Acceptance Criteria

clarify and document the reason for this behaviour
fix and document it if necessary

Stakeholder review needed before the work gets merged

[X] 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)
[X] Other (please specify)
- @worldlyjohn Data team

References

See @worldlyjohn comment on this PR https://github.com/MetaMask/metamask-mobile/pull/9905#issuecomment-2155321704

MetaMask / metamask-mobile