Race condition: "Taking longer than usual to connect"

[Curiousite]

Version

NPM: "botframework-webchat": "^4.6.0"

botframework-webchat:bundle:variant = full
botframework-webchat:bundle:version = 4.6.0
botframework-webchat:core:version = 4.6.0
botframework-webchat:ui:version = 4.6.0

Describe the bug

When Web-chat loses connection to the server but connection is reestablished within 15 seconds (before the "Taking longer than usual to connect" message is shown) then the message will appear after the chat is connected again and never disappear.

The error appears to originate from a call to "sleep" within detectSlowConnectionSaga.js, where the RECONNECT_FULFILLED status in connectivitystatus.js is overwritten by CONNECT_STILL_PENDING, hence showing the message.

Steps to reproduce

1. Establish a connection
2. Go offline
3. Reconnect within 15 seconds

Expected behavior

The slow-connection-warning-message should not appear after 15 seconds if connection is already reestablished.

[cwhitten]

Hi @Curiousite. Thank you for the issue and the contribution! We'll review the pull request soon. See #2656 for updates.

[compulim]

I have repro-ed the issue in test and found the main cause in this code instead, detectSlowConnectionSaga.js.

The code did not take account into RECONNECT_FULFILLED or RECONNECT_REJECTED.

I am working on a proper fix and test case.

export default function* detectSlowConnectionSaga() {
  for (;;) {
    yield take([CONNECT_PENDING, RECONNECT_PENDING]);

    const connectivityRace = yield race({
-     fulfilled: take(CONNECT_FULFILLED),
+     fulfilled: take([CONNECT_FULFILLED, RECONNECT_FULFILLED]),
-     rejected: take(CONNECT_REJECTED),
+     rejected: take([CONNECT_REJECTED, RECONNECT_REJECTED]),
      slow: call(() => sleep(SLOW_CONNECTION_AFTER))
    });

    if ('slow' in connectivityRace) {
      yield put({ type: CONNECT_STILL_PENDING });
    }
  }
}