chore!: rename getFeatureFlagResult sendEvent to sendFeatureFlagEvent

[turnipdabeets]

💡 Motivation and Context

Stacked on #637 (v6).

v6 renames the config option sendFeatureFlagEvents to sendFeatureFlagEvent (#636 / #638), but the per-call parameter on getFeatureFlagResult is still sendEvent, so one concept has two names. This renames it so everything matches:

• PostHogConfig.sendFeatureFlagEvent (Flutter)
• iOS getFeatureFlagResult(_ key:, sendFeatureFlagEvent:)
• Android getFeatureFlagResult(key, sendFeatureFlagEvent: Boolean?)
• the canonical option name in sdk-specs

v6 users already have to touch this setting for the config rename, so this is a hard rename in the major with no deprecation shim.

Migration:

// before
await Posthog().getFeatureFlagResult('my-flag', sendEvent: false);
// after
await Posthog().getFeatureFlagResult('my-flag', sendFeatureFlagEvent: false);

The parameter is also renamed on PosthogFlutterPlatformInterface.getFeatureFlagResult and its IO/web implementations (v6 is breaking for platform implementers anyway, same as #645).

Wire key: the method-channel argument key stays 'sendEvent'. Renaming it would touch the Kotlin and Swift plugins and the web handler for no user-facing benefit, the same choice as #645.

The getFeatureFlagPayload removal note in the #637 changeset now points to sendFeatureFlagEvent: false, so the v6 changelog doesn't recommend a name it also removes.

💚 How did you test it?

• flutter analyze: no issues
• flutter test: all 781 tests pass (existing getFeatureFlagResult tests updated to the new name; the IO tests still assert the 'sendEvent' wire key)
• dart format --set-exit-if-changed: clean
• scripts/check-api-dart.sh --update: api/posthog_flutter.api.json regenerated (3 param renames)

📝 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

🤖 Agent context

Autonomy: Human-driven (agent-assisted)

Written with Claude Code. Dart-only rename. Native plugins and the web handler are unchanged because the wire key is kept.

🤖 Generated with Claude Code

[github-actions]

posthog-flutter Compliance Report

Date: 2026-10-07 15:57:55 UTC
Duration: 96554ms

✅ All Tests Passed!

45/45 tests passed

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Capture Tests

✅ 29/29 tests passed

View Details

Test	Status	Duration
Format Validation.Event Has Required Fields	✅	130ms
Format Validation.Event Has Uuid	✅	113ms
Format Validation.Event Has Lib Properties	✅	112ms
Format Validation.Distinct Id Is String	✅	111ms
Format Validation.Token Is Present	✅	113ms
Format Validation.Custom Properties Preserved	✅	112ms
Format Validation.Event Has Timestamp	✅	113ms
Retry Behavior.Retries On 503	✅	5326ms
Retry Behavior.Does Not Retry On 400	✅	2113ms
Retry Behavior.Does Not Retry On 401	✅	2115ms
Retry Behavior.Respects Retry After Header	✅	8120ms
Retry Behavior.Implements Backoff	✅	15439ms
Retry Behavior.Retries On 500	✅	5221ms
Retry Behavior.Retries On 502	✅	5221ms
Retry Behavior.Retries On 504	✅	5221ms
Retry Behavior.Max Retries Respected	✅	15437ms
Deduplication.Generates Unique Uuids	✅	118ms
Deduplication.Preserves Uuid On Retry	✅	5220ms
Deduplication.Preserves Uuid And Timestamp On Retry	✅	10330ms
Deduplication.Preserves Uuid And Timestamp On Batch Retry	✅	5225ms
Deduplication.No Duplicate Events In Batch	✅	117ms
Deduplication.Different Events Have Different Uuids	✅	113ms
Compression.Sends Gzip When Enabled	✅	112ms
Batch Format.Uses Proper Batch Structure	✅	111ms
Batch Format.Flush With No Events Sends Nothing	✅	107ms
Batch Format.Multiple Events Batched Together	✅	118ms
Error Handling.Does Not Retry On 403	✅	2113ms
Error Handling.Does Not Retry On 413	✅	2114ms
Error Handling.Retries On 408	✅	5221ms

Feature_Flags Tests

✅ 16/16 tests passed

View Details

Test	Status	Duration
Request Payload.Request With Person Properties Device Id	✅	9ms
Request Payload.Flags Request Uses V2 Query Param	✅	7ms
Request Payload.Flags Request Hits Flags Path Not Decide	✅	6ms
Request Payload.Flags Request Omits Authorization Header	✅	7ms
Request Payload.Token In Flags Body Matches Init	✅	7ms
Request Payload.Groups Round Trip	✅	6ms
Request Payload.Groups Default To Empty Object	✅	7ms
Request Payload.Person Properties Distinct Id Auto Populated When Caller Omits It	✅	7ms
Request Payload.Disable Geoip False Propagates As Geoip Disable False	✅	8ms
Request Payload.Disable Geoip Omitted Defaults To False	✅	7ms
Request Payload.Flag Keys To Evaluate Contains Only Requested Key	✅	7ms
Request Lifecycle.No Flags Request On Init Alone	✅	2ms
Request Lifecycle.No Flags Request On Normal Capture	✅	109ms
Request Lifecycle.Two Flag Calls Produce Two Remote Requests	✅	11ms
Request Lifecycle.Mock Response Value Is Returned To Caller	✅	7ms
Side Effect Events.Get Feature Flag Captures Feature Flag Called Event	✅	110ms