Binary eio v3 + Engine IO v3, v4 Interop JS integration tests by sanjomo · Pull Request #228 · socketio4j/netty-socketio

sanjomo · 2026-07-30T18:04:37Z

Description

Brief description of the changes in this PR.

Type of Change

Bug fix (non-breaking change which fixes an issue)
New feature (non-breaking change which adds functionality)
Breaking change (fix or feature that would cause existing functionality to not work as expected)
Documentation update
Code refactoring
Test improvements
Build/tooling changes

Related Issue

Closes #(issue number)

Changes Made

Testing

All existing tests pass
New tests added for new functionality
Tests pass locally with mvn test
Integration tests pass (if applicable)

Checklist

Code follows project coding standards
Self-review completed
Code is commented where necessary
Documentation updated (if needed)
Commit messages follow conventional format
No merge conflicts
All CI checks pass

Additional Notes

Any additional information, screenshots, or context that reviewers should know.

Summary by CodeRabbit

New Features
- Added APIs for removing connection and disconnection listeners.
- Added binary-safe event serialization.
- Added a clustered example with distributed rooms, broadcasts, acknowledgments, and typed payloads.
Bug Fixes
- Improved Engine.IO v2–v4 polling and WebSocket compatibility, including binary attachments and response content types.
- Improved per-connection packet handling and distributed event reliability.
- Improved graceful shutdown handling for Redis and Kafka event stores.
Tests
- Expanded JavaScript interoperability, distributed scenarios, protocol compatibility, and resource-leak coverage.

Add correct Engine.IO version handling and robust binary framing support across transports. Introduce Packet.withEngineIOVersion to avoid mutating shared Packet instances during broadcasts; update Namespace, SingleRoomBroadcastOperations, EncoderHandler, PacketEncoder and PacketDecoder to emit/parse EIOv2/v3 polling wrappers, EIOv3 'b4' base64 text, WebSocket prefixes (0x04) and EIOv4 text/plain behavior. Enhance packet decoding with transport-aware logic and multi-packet separator handling. Enable safe polymorphic Jackson typing in Kafka/Hazelcast/NATS serializers/deserializers. Add many integration tests and JS interop fixtures (js-interop resources, test clients), update test containers/configs (Hazelcast image/xsd, Kafka consumer group/offsets), improve logging and example to show Hazelcast-backed clustering. Update .gitignore and bump dependencies in examples/pom.xml.

coderabbitai · 2026-07-30T18:04:58Z

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📝 Walkthrough

Walkthrough

The PR adds Engine.IO v2–v4 transport-aware packet processing, per-client packet isolation, shared event serialization, JavaScript and distributed integration tests, CI Node.js setup, Hazelcast updates, and a clustered Hazelcast-backed example.

Changes

Protocol and serialization

Layer / File(s)	Summary
Engine.IO codec and packet isolation `netty-socketio-core/src/main/java/com/socketio4j/socketio/protocol/`, `.../handler/`, `.../namespace/*`	Packet handling preserves per-client Engine.IO versions and supports transport-specific v2/v3/v4 framing, binary wrappers, polling separators, and attachment decoding.
Distributed event serialization and lifecycle `netty-socketio-core/src/main/java/com/socketio4j/socketio/store/`, `.../SocketIOServer.java`, `.../listener/`, `.../namespace/*`	A shared Jackson mapper serializes and restores `byte[]` values across event stores. Listener removal APIs, null-event handling, and Redisson shutdown handling are updated.

Interoperability and tests

Layer / File(s)	Summary
JavaScript client interoperability `netty-socketio-core/src/test/resources/js-interop/`, `.../integration/JsClientInteropTest.java`, `.../integration/ProtocolScenariosIntegrationTest.java`, `.../integration/EIOv3`	Node clients and Java tests cover Socket.IO versions 1–4, transports, acknowledgements, binary payloads, objects, POJOs, and Engine.IO v3 scenarios.
Distributed integration coverage `netty-socketio-core/src/test/java/com/socketio4j/socketio/integration/Distributed*`	Distributed tests add deterministic room synchronization, EIO v3 forwarding, JavaScript client matrices, and Hazelcast, Kafka, NATS, Redis Streams, and Redis PubSub backends.
Protocol robustness and resource tests `netty-socketio-core/src/test/java/com/socketio4j/socketio/{protocol,handler,transport,leak,namespace}/*`	Tests cover malformed packets, buffer leaks, concurrent room joins, invalid URLs, HTTP headers, WebSocket frames, server restarts, and memory-store cleanup.

Build and example

Layer / File(s)	Summary
CI and clustered example `.github/workflows/build.yml`, `.gitignore`, `pom.xml`, `netty-socketio-examples/netty-socketio-core-example/*`, `netty-socketio-core/src/test/resources/hazelcast-test-config.xml`	CI installs Node.js interop dependencies, Hazelcast versions and module opens are updated, and the example runs two Hazelcast-backed Socket.IO servers.

Estimated code review effort: 5 (Critical) | ~120 minutes

Possibly related PRs

socketio4j/netty-socketio#25: Updates Hazelcast versions in the Maven build.
socketio4j/netty-socketio#92: Refactors DistributedCommonTest room synchronization and assertions.
socketio4j/netty-socketio#213: Updates PacketDecoder and Engine.IO v3 binary attachment handling.

Suggested labels: enhancement

Suggested reviewers: neatguycoding

🚥 Pre-merge checks | ✅ 3 | ❌ 2

❌ Failed checks (2 warnings)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 17.71% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.
Description check	⚠️ Warning	The description retains the template but provides no concrete summary, selected change type, testing results, checklist status, or additional context.	Complete the description with the actual changes, related issue, selected change type, test results, checklist status, and relevant reviewer notes.

✅ Passed checks (3 passed)

Check name	Status	Explanation
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Title check	✅ Passed	The title clearly identifies the main EIO v3 protocol and JavaScript interoperability test changes.

✨ Finishing Touches 💡 1

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Commit on current branch

🧪 Generate unit tests (beta)

Create PR with unit tests
Commit unit tests in branch binary-eio-v3

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Add missing listener removals (ClientListeners/Namespace/SocketIOServer). Harden EncoderHandler/PacketDecoder parsing for Engine.IO polling: skip leading 0x1E delimiters, validate legacy length-prefixed polling wrappers, guard against unknown EngineIOVersion and use safe equals checks. Change PacketEncoder to emit 0x1E only for EIOv4 and use standard Base64 for EIOv4 polling attachments so browser clients decode '+' and '/'. Tweak EventMessageJsonSupport ObjectMapper to avoid empty-bean failures and related types. Add and update integration/unit tests and JS test client scenarios. Update test hazelcast container image and example pom dependency. Several test cleanup/logging robustness fixes.

Adjust polling encoding and HTTP headers to correctly support Engine.IO v4. EncoderHandler now selects text/plain for v4 polling (and for non-binary payloads), and PacketEncoder was rewritten to handle EIO v4 multi-packet polling (0x1E delimiter) with STANDARD Base64 for attachments, while preserving v2/v3 binary envelope behavior. Buffer handling, length-prefixing and resource releases were improved and unsupported versions now throw. Unit tests updated to reflect v4/v3 differences, JSONP behavior, and use StandardCharsets.

PacketDecoder: treat PONG like PING (read text payload), fix polling length-header digit validation, and add explicit ERROR body parsing with JSON fallback. Tests: significantly expand PacketDecoderTest and PacketEncoderTest to cover Engine.IO V2/V3/V4, binary attachments, XHR2 polling binary frames, ping/pong, ACKs and ERRORs. Integration tests and JS interop fixtures updated to improve distributed room/isolation/leave checks and to fail/pass cleanly; added connect/event presence assertions in JsClientInteropTest. Minor test whitespace cleanup. These changes improve protocol compatibility and increase test coverage for binary and cross-version behaviors.

Suppress XREAD error noise during shutdown in RedisStreamEventStore by checking the running flag and detecting Redisson shutdown (exception type/cause/message). Add a suite of robustness and edge-case unit tests: WrongUrlHandlerTest, ByteBufLeakTest (Netty PARANOID leak detection), PacketDecoderFuzzingTest, SocketSslServerRestartTest (rapid restarts), WebSocketTransportTest (binary frame + mocks), HttpTransportTest (polling headers), MemoryStoreTest (session expunge), and NamespaceTest (concurrent room joins). Also adjust test helpers/mocks where needed.

Remove an unused JsonTypeInfo import from Packet.java. Rework PacketDecoder branching for polling payloads: move the Base64 polling ('b') handling (and its separator-slicing logic) into the else-if branch and place the fallback binary polling payload in the final else branch. This clarifies control flow and ensures the polling attachment paths are handled correctly.

@OverRide

Use try-with-resources and finally to properly release ByteBuf/InputStream resources in PacketDecoder and PacketEncoder to prevent leaks and correctly handle JSONP framing. Add @OverRide annotations to PacketDecoderFuzzingTest lifecycle methods. Add Apache-2.0 license headers to JS test resource files. These changes improve resource safety and clarity without altering protocol behavior.

coderabbitai · 2026-07-31T18:30:16Z

Note

Autofix is a beta feature. Expect some limitations and changes as we gather feedback and continue to improve it.

Fixes Applied Successfully

Fixed 2 file(s) based on 2 unresolved review comments.

Files modified:

netty-socketio-core/src/test/java/com/socketio4j/socketio/SocketSslServerRestartTest.java
netty-socketio-core/src/test/java/com/socketio4j/socketio/protocol/PacketDecoderFuzzingTest.java

Commit: 73254cb437855750a8864fd185413fef0a55f405

The changes have been pushed to the binary-eio-v3 branch.

Time taken: 2m 32s

Fixed 2 file(s) based on 2 unresolved review comments. Co-authored-by: CodeRabbit <noreply@coderabbit.ai>

server always gets immutable copy of config so changing port have no effect

coderabbitai · 2026-08-01T04:24:15Z

Note

Docstrings generation - SUCCESS
Generated docstrings for this pull request at #229

@sanjomo

Docstrings generation was requested by @sanjomo. * #228 (comment) The following files were modified: * `netty-socketio-core/src/main/java/com/socketio4j/socketio/SingleRoomBroadcastOperations.java` * `netty-socketio-core/src/main/java/com/socketio4j/socketio/SocketIOServer.java` * `netty-socketio-core/src/main/java/com/socketio4j/socketio/handler/EncoderHandler.java` * `netty-socketio-core/src/main/java/com/socketio4j/socketio/handler/InPacketHandler.java` * `netty-socketio-core/src/main/java/com/socketio4j/socketio/listener/ClientListeners.java` * `netty-socketio-core/src/main/java/com/socketio4j/socketio/namespace/Namespace.java` * `netty-socketio-core/src/main/java/com/socketio4j/socketio/protocol/JacksonJsonSupport.java` * `netty-socketio-core/src/main/java/com/socketio4j/socketio/protocol/Packet.java` * `netty-socketio-core/src/main/java/com/socketio4j/socketio/protocol/PacketDecoder.java` * `netty-socketio-core/src/main/java/com/socketio4j/socketio/protocol/PacketEncoder.java` * `netty-socketio-core/src/main/java/com/socketio4j/socketio/store/event/EventMessageJsonSupport.java` * `netty-socketio-core/src/main/java/com/socketio4j/socketio/store/hazelcast/HazelcastPubSubEventStore.java` * `netty-socketio-core/src/main/java/com/socketio4j/socketio/store/kafka/serialization/EventMessageDeserializer.java` * `netty-socketio-core/src/main/java/com/socketio4j/socketio/store/kafka/serialization/EventMessageSerializer.java` * `netty-socketio-core/src/main/java/com/socketio4j/socketio/store/nats_pubsub/EventMessageCodec.java` * `netty-socketio-core/src/main/java/com/socketio4j/socketio/store/redis_stream/RedisStreamEventStore.java` * `netty-socketio-core/src/test/java/com/socketio4j/socketio/store/CustomizedHazelcastContainer.java` * `netty-socketio-examples/netty-socketio-core-example/src/main/java/com/socketio4j/example/core/CoreExampleMain.java`

devin-ai-integration

Devin Review found 1 new potential issue.

View 17 additional findings in Devin Review.

+    @AfterAll
+    static void stopKafka() {
+        TestResourceCleanup.runAll("Kafka test container cleanup",
+                () -> { if (KAFKA != null && KAFKA.isRunning()) KAFKA.close(); });


+    @AfterAll
+    static void stopNats() {
+        TestResourceCleanup.runAll("NATS test container cleanup",
+                () -> { if (NATS_CONTAINER != null && NATS_CONTAINER.isRunning()) NATS_CONTAINER.stop(); });


+                () -> { if (node2 != null) node2.stop(); },
+                () -> { if (kafkaEventStore1 != null) kafkaEventStore1.shutdown(); },
+                () -> { if (kafkaEventStore2 != null) kafkaEventStore2.shutdown(); },
+                () -> { if (KAFKA != null && KAFKA.isRunning()) KAFKA.close(); });


+    uses: ./.github/workflows/build.yml
+    with:
+      javaVersion: "21"
+      interopVersions: "full"
+
+  publish:


+        okWebSocket.send(ByteString.of(new byte[]{(byte) 0xFF, (byte) 0xFF, (byte) 0xFF}));
+
+        // 4. Send valid Engine.IO PING packet to verify server Netty pipeline is still healthy
+        CountDownLatch pongLatch = new CountDownLatch(1);


sanjomo added 3 commits July 30, 2026 20:19

Add lossless JSON byte[] support and tests

dc28d25

Update build.yml

cc5676c