Files
sdk/pkg/dds
Ben Konyi ab6780d13e [dds][dart_runtime_service] Dynamically allocate ChromeDriver ports and fix SSE test flakiness
This change addresses flakiness in SSE tests caused by port conflicts
and race conditions during connection teardown.

Key changes:
- Dynamically allocates ChromeDriver ports in `sse_smoke_test.dart` and `sse_client_test.dart` instead of using a hardcoded port (4444). This avoids conflicts when tests run in parallel on CI bots.
- Adds support for locating ChromeDriver via the `CHROMEDRIVER_PATH` environment variable in both test suites.
- Updates `sse_smoke_driver.dart` to introduce a brief delay before closing connections. This ensures the client-side SseClient has sufficient time to flush its final POST request to the server, avoiding "Bad state: No element" errors.
- Modifies `test_helper.dart` to filter out `--mark_main_isolate_as_system_isolate` from arguments forwarded to spawned testee processes. This is necessary under modern `dart test` runners to ensure processes pause at start as expected.

Change-Id: Idf45cd69f366ec6b6f81cfed955aea337b277dcc
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/508343
Auto-Submit: Ben Konyi <bkonyi@google.com>
Reviewed-by: Mark Zhou <markzipan@google.com>
Commit-Queue: Mark Zhou <markzipan@google.com>
2026-06-02 12:46:31 -07:00
..

pub package package publisher

A package used to spawn the Dart Developer Service (DDS), which is used to communicate with a Dart VM Service instance and provide extended functionality to the core VM Service Protocol.

Functionality

Existing VM Service clients can issue both HTTP, websocket, and SSE requests to a running DDS instance as if it were an instance of the VM Service itself. If a request corresponds to an RPC defined in the VM Service Protocol, DDS will forward the request and return the response from the VM Service. Requests corresponding to an RPC defined in the DDS Protocol will be handled directly by the DDS instance.

SSE Support

For certain web clients it may be preferable or required to communicate with DDS using server-sent events (SSE). DDS has an SSE handler listening for requests on /$debugHandler.

SSE and package:vm_service example

import 'package:sse/sse.dart';
import 'package:vm_service/vm_service.dart';

void main() {
  // Establish connection with DDS using SSE.
  final ddsChannel = SseClient('${ddsUri}\$debugHandler');

  // Wait for ddsChannel to be established
  await ddsChannel.onOpen.first;

  // Initialize VmService using the sink and stream from ddsChannel.
  final vmService = VmService(
    ddsChannel.stream,
    (e) => ddsChannel.sink.add(e),
  );

  // You're ready to query DDS and the VM service!
  print(await vmService.getVersion());
}