POC: deduplicate dry4swift findings

[marandaneto]

💡 Motivation and Context

POC for using dry4swift to identify structural duplicate Swift code and apply low-risk deduplication in the iOS SDK.

This PR intentionally focuses on mechanical/refactor-only changes where shared helpers reduce duplicate implementation patterns without changing public behavior.

Key examples:

• shared integration install/uninstall state handling
• shared survey enum string decoding helper
• shared remote-config cached value/dictionary helpers
• shared SDK helpers for autocapture/rageclick, feature events, and exception capture
• shared URLSession request execution and a few small replay/survey UI helpers

The initial dry4swift candidate count was reduced from 203 to 120 after the POC refactors.

💚 How did you test it?

• make format
• make test — 559 tests passed
• Re-ran dry4swift locally to compare duplicate candidate counts

📝 Checklist

• I reviewed the submitted code.
• I added tests to verify the changes.
• I updated the docs if needed.
• No breaking change or entry added to the changelog.

If releasing new changes

• Ran pnpm changeset to generate a changeset file

[marandaneto]

PoC for https://github.com/marandaneto/dry4swift

[github-actions]

posthog-ios Compliance Report

Date: 2026-05-27 15:56:54 UTC
Duration: 4553ms

⚠️ Some Tests Failed

1/16 tests passed, 15 failed

---

Feature_Flags Tests

⚠️ 1/16 tests passed, 15 failed

View Details

Test	Status	Duration
Request Payload.Request With Person Properties Device Id	❌	106ms
Request Payload.Flags Request Uses V2 Query Param	❌	150ms
Request Payload.Flags Request Hits Flags Path Not Decide	❌	147ms
Request Payload.Flags Request Omits Authorization Header	❌	126ms
Request Payload.Token In Flags Body Matches Init	❌	97ms
Request Payload.Groups Round Trip	❌	77ms
Request Payload.Groups Default To Empty Object	❌	111ms
Request Payload.Person Properties Distinct Id Auto Populated When Caller Omits It	❌	106ms
Request Payload.Disable Geoip False Propagates As Geoip Disable False	❌	102ms
Request Payload.Disable Geoip Omitted Defaults To False	❌	111ms
Request Payload.Flag Keys To Evaluate Contains Only Requested Key	❌	100ms
Request Lifecycle.No Flags Request On Init Alone	✅	62ms
Request Lifecycle.No Flags Request On Normal Capture	❌	2239ms
Request Lifecycle.Two Flag Calls Produce Two Remote Requests	❌	122ms
Request Lifecycle.Mock Response Value Is Returned To Caller	❌	112ms
Side Effect Events.Get Feature Flag Captures Feature Flag Called Event	❌	116ms

Failures

request_payload.request_with_person_properties_device_id

404, message='Not Found', url='http://host.docker.internal:8080/get_feature_flag'

request_payload.flags_request_uses_v2_query_param

404, message='Not Found', url='http://host.docker.internal:8080/get_feature_flag'

request_payload.flags_request_hits_flags_path_not_decide

404, message='Not Found', url='http://host.docker.internal:8080/get_feature_flag'

request_payload.flags_request_omits_authorization_header

404, message='Not Found', url='http://host.docker.internal:8080/get_feature_flag'

request_payload.token_in_flags_body_matches_init

404, message='Not Found', url='http://host.docker.internal:8080/get_feature_flag'

request_payload.groups_round_trip

404, message='Not Found', url='http://host.docker.internal:8080/get_feature_flag'

request_payload.groups_default_to_empty_object

404, message='Not Found', url='http://host.docker.internal:8080/get_feature_flag'

request_payload.person_properties_distinct_id_auto_populated_when_caller_omits_it

404, message='Not Found', url='http://host.docker.internal:8080/get_feature_flag'

request_payload.disable_geoip_false_propagates_as_geoip_disable_false

404, message='Not Found', url='http://host.docker.internal:8080/get_feature_flag'

request_payload.disable_geoip_omitted_defaults_to_false

404, message='Not Found', url='http://host.docker.internal:8080/get_feature_flag'

request_payload.flag_keys_to_evaluate_contains_only_requested_key

404, message='Not Found', url='http://host.docker.internal:8080/get_feature_flag'

request_lifecycle.no_flags_request_on_normal_capture

Expected 0 /flags requests, got 2

request_lifecycle.two_flag_calls_produce_two_remote_requests

404, message='Not Found', url='http://host.docker.internal:8080/get_feature_flag'

request_lifecycle.mock_response_value_is_returned_to_caller

404, message='Not Found', url='http://host.docker.internal:8080/get_feature_flag'

side_effect_events.get_feature_flag_captures_feature_flag_called_event

404, message='Not Found', url='http://host.docker.internal:8080/get_feature_flag'

[marandaneto]

@ioannisj @turnipdabeets wdyt? this could be in CI as well

[ioannisj]

@ioannisj @turnipdabeets wdyt? this could be in CI as well

Had me at installIfNeeded()

[ioannisj]

No familiar at all with dry4swift and can't find it online? Is this under github.com/dryproject?

[marandaneto]

dry4swift

https://github.com/marandaneto/dry4swift

i have made a similar pr for python PostHog/posthog-python#623