fix(flags): align presence operator semantics

[marandaneto]

💡 Motivation and Context

sdk-specs PR #49 defines omitted properties as inconclusive because SDK property maps contain partial context. The Rust local evaluator returned false for missing is_set properties and true for missing is_not_set properties.

This change returns InconclusiveMatchError when either presence operator's key is omitted. Present keys remain conclusive, including null and other falsey values.

💚 How did you test it?

• cargo fmt --all -- --check
• cargo test --lib test_is_set_operator
• cargo test --lib test_is_not_set_operator
• cargo test --lib (231 tests passed)
• Autoreview completed with no actionable findings.

📝 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 sampo add to generate a changeset file

🤖 Agent context

Autonomy: Human-driven (agent-assisted)

Pi coding agent worker subagents implemented and validated the focused matcher change. The bundled autoreview tool reviewed the final committed diff against origin/main.

[github-actions]

posthog-rs-v0 Compliance Report

Date: 2026-08-26 07:50:58 UTC
Duration: 15564ms

✅ All Tests Passed!

46/46 tests passed

---

Capture Tests

✅ 29/29 tests passed

View Details

Test	Status	Duration
Format Validation.Event Has Required Fields	✅	158ms
Format Validation.Event Has Uuid	✅	167ms
Format Validation.Event Has Lib Properties	✅	166ms
Format Validation.Distinct Id Is String	✅	158ms
Format Validation.Token Is Present	✅	161ms
Format Validation.Custom Properties Preserved	✅	160ms
Format Validation.Event Has Timestamp	✅	157ms
Retry Behavior.Retries On 503	✅	5162ms
Retry Behavior.Does Not Retry On 400	✅	2161ms
Retry Behavior.Does Not Retry On 401	✅	2159ms
Retry Behavior.Respects Retry After Header	✅	5095ms
Retry Behavior.Implements Backoff	✅	15105ms
Retry Behavior.Retries On 500	✅	5093ms
Retry Behavior.Retries On 502	✅	5098ms
Retry Behavior.Retries On 504	✅	5099ms
Retry Behavior.Max Retries Respected	✅	15099ms
Deduplication.Generates Unique Uuids	✅	100ms
Deduplication.Preserves Uuid On Retry	✅	5025ms
Deduplication.Preserves Uuid And Timestamp On Retry	✅	10034ms
Deduplication.Preserves Uuid And Timestamp On Batch Retry	✅	5040ms
Deduplication.No Duplicate Events In Batch	✅	25ms
Deduplication.Different Events Have Different Uuids	✅	22ms
Compression.Sends Gzip When Enabled	✅	23ms
Batch Format.Uses Proper Batch Structure	✅	24ms
Batch Format.Flush With No Events Sends Nothing	✅	26ms
Batch Format.Multiple Events Batched Together	✅	107ms
Error Handling.Does Not Retry On 403	✅	2093ms
Error Handling.Does Not Retry On 413	✅	2096ms
Error Handling.Retries On 408	✅	5081ms

Feature_Flags Tests

✅ 17/17 tests passed

View Details

Test	Status	Duration
Request Payload.Request With Person Properties Device Id	✅	76ms
Request Payload.Flags Request Uses V2 Query Param	✅	57ms
Request Payload.Flags Request Hits Flags Path Not Decide	✅	22ms
Request Payload.Flags Request Omits Authorization Header	✅	42ms
Request Payload.Token In Flags Body Matches Init	✅	36ms
Request Payload.Groups Round Trip	✅	48ms
Request Payload.Groups Default To Empty Object	✅	46ms
Request Payload.Disable Geoip False Propagates As Geoip Disable False	✅	33ms
Request Payload.Disable Geoip Omitted Defaults To False	✅	28ms
Request Payload.Flag Keys To Evaluate Contains Only Requested Key	✅	38ms
Request Lifecycle.No Flags Request On Init Alone	✅	23ms
Request Lifecycle.No Flags Request On Normal Capture	✅	46ms
Request Lifecycle.Two Flag Calls Produce Two Remote Requests	✅	42ms
Request Lifecycle.Mock Response Value Is Returned To Caller	✅	41ms
Retry Behavior.Retries Flags On 502	✅	235ms
Retry Behavior.Retries Flags On 504	✅	247ms
Side Effect Events.Get Feature Flag Captures Feature Flag Called Event	✅	50ms

[github-actions]

posthog-rs-v1 Compliance Report

Date: 2026-08-26 07:51:07 UTC
Duration: 23052ms

✅ All Tests Passed!

111/111 tests passed

---

Capture_V1 Tests

✅ 94/94 tests passed

View Details

Test	Status	Duration
Endpoint And Method.Targets V1 Endpoint	✅	151ms
Endpoint And Method.Does Not Use Legacy Endpoints	✅	150ms
Required Headers.Has Authorization Bearer Header	✅	149ms
Required Headers.Has Content Type Json	✅	149ms
Required Headers.Has Posthog Sdk Info Format	✅	149ms
Required Headers.Has Posthog Attempt Header	✅	149ms
Required Headers.Has Posthog Request Id	✅	149ms
Required Headers.Has Posthog Request Timestamp	✅	147ms
Required Headers.Has User Agent	✅	154ms
Body Format.Body Has Created At And Batch	✅	147ms
Body Format.No Api Key In Body	✅	142ms
Body Format.No Sent At In Body	✅	142ms
Event Format.Event Has Required Root Fields	✅	143ms
Event Format.Event Uuid Is Valid	✅	141ms
Event Format.Event Timestamp Is Rfc3339	✅	141ms
Event Format.Distinct Id Is String	✅	142ms
Event Format.Distinct Id At Root Not Properties	✅	140ms
Event Format.Custom Properties Preserved	✅	142ms
Event Format.Set Properties Preserved	✅	140ms
Event Format.Set Once Properties Preserved	✅	138ms
Event Format.Groups Properties Preserved	✅	130ms
Event Format.Sdk Generates Uuid If Not Provided	✅	141ms
Event Format.Event Has Required Root Fields Batch	✅	168ms
Event Format.Event Uuid Is Valid Batch	✅	169ms
Event Format.Event Timestamp Is Rfc3339 Batch	✅	169ms
Event Format.Distinct Id Is String Batch	✅	167ms
Event Format.Distinct Id At Root Not Properties Batch	✅	167ms
Event Format.Custom Properties Preserved Batch	✅	167ms
Event Format.Set Properties Preserved Batch	✅	187ms
Event Format.Set Once Properties Preserved Batch	✅	166ms
Event Format.Groups Properties Preserved Batch	✅	136ms
Event Format.Sdk Generates Uuid If Not Provided Batch	✅	151ms
Batch Behavior.Multiple Events In Single Batch	✅	184ms
Batch Behavior.Batch Envelope Smoke	✅	179ms
Batch Behavior.Flush With No Events Sends Nothing	✅	98ms
Batch Behavior.Flush At Triggers Batch	✅	1127ms
Batch Behavior.Created At Reflects Batch Creation Time	✅	119ms
Deduplication.Generates Unique Uuids	✅	183ms
Deduplication.Different Events Same Content Different Uuids	✅	154ms
Deduplication.Preserves Uuid On Retry	✅	5134ms
Deduplication.Preserves Timestamp On Retry	✅	5077ms
Deduplication.Preserves Uuid And Timestamp On Batch Retry	✅	5136ms
Deduplication.No Duplicate Events In Batch	✅	119ms
Header Behavior On Retry.Attempt Header Starts At One	✅	67ms
Header Behavior On Retry.Attempt Header Increments On Retry	✅	10079ms
Header Behavior On Retry.Request Id Preserved On Retry	✅	5059ms
Header Behavior On Retry.Different Requests Have Different Request Ids	✅	2068ms
Header Behavior On Retry.Request Timestamp Changes On Retry	✅	5065ms
Response Format Validation.Success Response Has Uuid Keyed Results	✅	67ms
Response Format Validation.Success Response Has Ok For Each Event	✅	41ms
Response Format Validation.Success No Retry After When All Ok	✅	29ms
Response Format Validation.Success Retry After Present When Retry Events	✅	29ms
Response Format Validation.Success No Retry After When Drop Only	✅	28ms
Response Format Validation.Response Echoes Request Id	✅	25ms
Retry Behavior.Retries On 408	✅	5029ms
Retry Behavior.Retries On 500	✅	5024ms
Retry Behavior.Retries On 503	✅	5025ms
Retry Behavior.Retries On 504	✅	5023ms
Retry Behavior.Retryable Errors Have Retry After	✅	2027ms
Retry Behavior.Respects Retry After On Retryable Error	✅	8024ms
Retry Behavior.Does Not Retry On 400	✅	2032ms
Retry Behavior.Does Not Retry On 401	✅	2044ms
Retry Behavior.Does Not Retry On 402	✅	2040ms
Retry Behavior.Does Not Retry On 413	✅	2024ms
Retry Behavior.Does Not Retry On 415	✅	2024ms
Retry Behavior.Non Retryable Errors Have No Retry After	✅	2025ms
Retry Behavior.Implements Backoff	✅	15031ms
Retry Behavior.Max Retries Respected	✅	15033ms
Partial Batch Handling.Handles 200 Full Success	✅	2035ms
Partial Batch Handling.Handles 200 With All Ok	✅	3049ms
Partial Batch Handling.Does Not Retry Dropped Events	✅	3036ms
Partial Batch Handling.Does Not Retry Limited Events	✅	3026ms
Partial Batch Handling.Prunes Ok Events On Partial Retry	✅	5027ms
Partial Batch Handling.Prunes Dropped Events On Partial Retry	✅	5025ms
Partial Batch Handling.Retries Only Retry Events From Partial	✅	5026ms
Partial Batch Handling.Partial Retry Preserves Uuids	✅	5024ms
Partial Batch Handling.Partial Retry Attempt Header Increments	✅	5034ms
Partial Batch Handling.Partial Retry Request Id Preserved	✅	5035ms
Partial Batch Handling.Respects Retry After On Partial	✅	5024ms
Partial Batch Handling.Unknown Result Treated As Terminal	✅	3024ms
Partial Batch Handling.Mixed Ok Drop Limited No Retry	✅	3033ms
Compression.Sends Gzip Content Encoding	✅	34ms
Compression.No Content Encoding When Disabled	✅	22ms
Compression.Compressed Body Is Decompressible	✅	21ms
Error Handling.Does Not Retry On Unknown 4Xx	✅	2023ms
Event Options.Cookieless Mode Override	✅	23ms
Event Options.Disable Skew Correction Override	✅	22ms
Event Options.Process Person Profile Override	✅	21ms
Event Options.Product Tour Id Override	✅	21ms
Event Options.Unset Options Omitted	✅	21ms
Event Options.Options Override In Batch	✅	22ms
Geoip And Historical Migration.Geoip Disable Injected Into Properties	✅	21ms
Geoip And Historical Migration.Historical Migration Set In Body	✅	21ms
Geoip And Historical Migration.Historical Migration Absent By Default	✅	21ms

Feature_Flags Tests

✅ 17/17 tests passed

View Details

Test	Status	Duration
Request Payload.Request With Person Properties Device Id	✅	14ms
Request Payload.Flags Request Uses V2 Query Param	✅	14ms
Request Payload.Flags Request Hits Flags Path Not Decide	✅	14ms
Request Payload.Flags Request Omits Authorization Header	✅	15ms
Request Payload.Token In Flags Body Matches Init	✅	15ms
Request Payload.Groups Round Trip	✅	17ms
Request Payload.Groups Default To Empty Object	✅	14ms
Request Payload.Disable Geoip False Propagates As Geoip Disable False	✅	14ms
Request Payload.Disable Geoip Omitted Defaults To False	✅	16ms
Request Payload.Flag Keys To Evaluate Contains Only Requested Key	✅	14ms
Request Lifecycle.No Flags Request On Init Alone	✅	11ms
Request Lifecycle.No Flags Request On Normal Capture	✅	26ms
Request Lifecycle.Two Flag Calls Produce Two Remote Requests	✅	16ms
Request Lifecycle.Mock Response Value Is Returned To Caller	✅	14ms
Retry Behavior.Retries Flags On 502	✅	216ms
Retry Behavior.Retries Flags On 504	✅	217ms
Side Effect Events.Get Feature Flag Captures Feature Flag Called Event	✅	23ms

[greptile-apps]

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