Flaky CI Failure: browser-sdk Dm 'should stream messages' — expected 2 streamed messages but got 1

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Flaky CI Failure: browser-sdk Dm 'should stream messages' — expected 2 streamed messages but got 1

Workflow: Test
Failed run: https://github.com/xmtp/libxmtp/actions/runs/29293048133
Commit: 41b9afb
Failed jobs: test-browser-sdk / Test (browser-sdk) shard 3

Summary

The Dm > should stream messages test in test/Dm.test.ts failed an assertion that the stream received 2 messages. Only 1 message was received before the stream completed, suggesting a race condition in message streaming where the second message arrives after the stream consumer has already stopped listening. All other 196 browser-sdk tests passed in this run.

Error Details

FAIL  chromium  test/Dm.test.ts > Dm > should stream messages
AssertionError: expected 1 to be 2 // Object.is equality

- Expected
+ Received

- 2
+ 1

 ❯ test/Dm.test.ts:186:18

    184|     expect(message).toBeDefined();
    185|   }
    186|   expect(count).toBe(2);
       |                  ^
    187|   expect(streamedMessages).toEqual(["gm", "gm2"]);

error: recipe `test-browser-sdk-ci` failed on line 41 with exit code 1

Analysis

This is a test code failure (likely a race condition / flaky streaming test), not an infrastructure failure. The test streams DM messages and asserts 2 messages are received, but only 1 arrives within the test's window. This pattern — stream consumers missing the last message — is consistent with timing sensitivity in streaming tests. A similar flaky pattern has been observed in the node-sdk streaming tests (#3831). The affected area is test/Dm.test.ts around line 186 in the browser-sdk test suite.

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Reported by Flaky Failure Watcher