ab6780d13e
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>