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fix: filter read_events by event_type to prevent projection stalls#373

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jwilger merged 1 commit intomainfrom
fix/read-events-event-type-filtering
Apr 15, 2026
Merged

fix: filter read_events by event_type to prevent projection stalls#373
jwilger merged 1 commit intomainfrom
fix/read-events-event-type-filtering

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@jwilger-ai-bot jwilger-ai-bot commented Apr 15, 2026

Summary

  • read_events silently drops events that fail deserialization via .ok(), and the LIMIT/.take() is applied before the deserialization filter. When a batch consists entirely of non-matching event types, the projection pipeline sees zero events and stops — permanently stuck.
  • All three backends now filter by event_type at the query/scan level so non-matching events never consume batch slots.
  • The projection pipeline explicitly passes E::event_type_name() in the EventFilter, and all backends fall back to it when no explicit filter is set.

Changes

File Change
eventcore-types/src/projection.rs Add event_type: Option<String> to EventFilter with builder and accessor
eventcore-memory/src/lib.rs Store event_type in GlobalLogEntry, filter before .take()
eventcore-postgres/src/lib.rs Add WHERE event_type = $N to all 4 SQL query branches
eventcore-sqlite/src/lib.rs Add AND event_type = ?N to all 4 SQL query branches
eventcore/src/projection_pipeline.rs Set event_type from E::event_type_name() in ReadEvents effect
eventcore/tests/mixed_event_type_projection_test.rs New test proving the bug and validating the fix
Cargo.lock Update rustls-webpki 0.103.10 → 0.103.12 (security advisory fix)

Test plan

  • New test read_events_returns_matching_events_when_preceded_by_other_types — seeds 5 AlphaEvents + 1 BetaEvent, calls read_events::<BetaEvent> with batch size 3, asserts 1 event returned (was 0 before fix)
  • New test run_projection_processes_events_when_other_event_types_exist — full run_projection integration test with mixed event types
  • All 195 existing tests pass
  • cargo clippy, cargo fmt, cargo audit all clean

Closes #372

@jwilger-ai-bot
fix: filter read_events by event_type to prevent projection stalls
cebc1aa 
When `read_events` is called, the LIMIT/take is applied before
deserialization filtering. If the events table contains events of mixed
types, non-matching events consume batch slots. When an entire batch
consists of non-matching types, the projection pipeline sees zero events
and stops — permanently stuck behind a block of unrelated events.

All three backends (postgres, sqlite, memory) already store event_type
during append. This commit adds event_type filtering at the query/scan
level so non-matching events never consume batch slots:

- Add `event_type` field to `EventFilter` with builder/accessor methods
- In-memory backend: store event_type in GlobalLogEntry, filter before
  .take()
- PostgreSQL backend: add WHERE event_type = $N to all SQL branches
- SQLite backend: add AND event_type = ?N to all SQL branches
- Projection pipeline: set event_type from E::event_type_name() in the
  ReadEvents effect
- All backends fall back to E::event_type_name() when no explicit filter
  is set

Closes #372
@jwilger jwilger enabled auto-merge (squash) April 15, 2026 18:21
@jwilger jwilger merged commit d516c24 into main Apr 15, 2026
18 checks passed
@jwilger jwilger deleted the fix/read-events-event-type-filtering branch April 15, 2026 18:25
@jwilger jwilger mentioned this pull request Apr 15, 2026
Merged
jwilger-ai-bot pushed a commit that referenced this pull request Apr 17, 2026
@jwilger
chore: release v0.7.1 (#375)
807bb8a 
## 🤖 New release

* `eventcore-macros`: 0.7.0 -> 0.7.1
* `eventcore-types`: 0.7.0 -> 0.7.1 (✓ API compatible changes)
* `eventcore-postgres`: 0.7.0 -> 0.7.1 (✓ API compatible changes)
* `eventcore-sqlite`: 0.7.0 -> 0.7.1 (✓ API compatible changes)
* `eventcore`: 0.7.0 -> 0.7.1 (✓ API compatible changes)
* `eventcore-memory`: 0.7.0 -> 0.7.1 (✓ API compatible changes)
* `eventcore-testing`: 0.7.0 -> 0.7.1 (✓ API compatible changes)
* `eventcore-examples`: 0.7.0 -> 0.7.1

<details><summary><i><b>Changelog</b></i></summary><p>

## `eventcore-macros`

<blockquote>

##
[0.7.0](eventcore-macros-v0.6.0...eventcore-macros-v0.7.0)
- 2026-04-13

### Bug Fixes

- improve error message consistency, context, and safety across all
crates ([#352](#352))

### Features

- enhance require! macro to accept typed error values
([#335](#335))
- add required event_type_name() to Event trait for stable storage
([#344](#344))

### Miscellaneous Tasks

- adopt han plugins, blueprints, and project conventions
([#330](#330))
- consolidate workspace lints and enforce strict lint policy
([#351](#351))

### Refactoring

- expose projection config via free function API, then reduce public
surface ([#357](#357))
</blockquote>

## `eventcore-types`

<blockquote>

##
[0.7.1](eventcore-types-v0.7.0...eventcore-types-v0.7.1)
- 2026-04-15

### Bug Fixes

- filter read_events by event_type to prevent projection stalls
([#373](#373))
</blockquote>

## `eventcore-postgres`

<blockquote>

##
[0.7.1](eventcore-postgres-v0.7.0...eventcore-postgres-v0.7.1)
- 2026-04-15

### Bug Fixes

- filter read_events by event_type to prevent projection stalls
([#373](#373))

### Features

- add load-testing/stress-testing suite
([#370](#370))
</blockquote>

## `eventcore-sqlite`

<blockquote>

##
[0.7.1](eventcore-sqlite-v0.7.0...eventcore-sqlite-v0.7.1)
- 2026-04-15

### Bug Fixes

- filter read_events by event_type to prevent projection stalls
([#373](#373))
</blockquote>

## `eventcore`

<blockquote>

##
[0.7.1](eventcore-v0.7.0...eventcore-v0.7.1)
- 2026-04-15

### Bug Fixes

- filter read_events by event_type to prevent projection stalls
([#373](#373))

### Features

- add load-testing/stress-testing suite
([#370](#370))
</blockquote>

## `eventcore-memory`

<blockquote>

##
[0.7.1](eventcore-memory-v0.7.0...eventcore-memory-v0.7.1)
- 2026-04-15

### Bug Fixes

- filter read_events by event_type to prevent projection stalls
([#373](#373))
</blockquote>

## `eventcore-testing`

<blockquote>

##
[0.7.1](eventcore-testing-v0.7.0...eventcore-testing-v0.7.1)
- 2026-04-15

### Features

- add load-testing/stress-testing suite
([#370](#370))
</blockquote>

## `eventcore-examples`

<blockquote>

##
[0.7.0](eventcore-examples-v0.6.0...eventcore-examples-v0.7.0)
- 2026-04-13

### Bug Fixes

- improve error message consistency, context, and safety across all
crates ([#352](#352))

### Features

- add required event_type_name() to Event trait for stable storage
([#344](#344))
- add TestScenario GWT testing helpers to eventcore-testing
([#346](#346))

### Miscellaneous Tasks

- consolidate workspace lints and enforce strict lint policy
([#351](#351))

### Refactoring

- replace into_inner() with into() for nutype domain types
([#334](#334))
- expose projection config via free function API, then reduce public
surface ([#357](#357))
</blockquote>


</p></details>

---
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[release-plz](https://github.com/release-plz/release-plz/).
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PostgreSQL read_events silently drops events that fail deserialization

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