TypeError: Cannot read properties of null (reading 'status') at SSE._onStreamFailure

[vojtabohm]

This error happens when the connection to a server is refused. For example if you don't have proper CSP or the server just refuses.

In the method:

this._onStreamFailure = function(e) {
    const event = new CustomEvent('error');
    event.responseCode = this.xhr.status;
    event.data = e.currentTarget.response;
    this.dispatchEvent(event);
    this._markClosed();
  }

The xhr object seems to be null:
at SSE._onStreamFailure (webpack-internal:///./node_modules/sse.js/lib/sse.js:155:35)

[mpetazzoni]

Thanks for reporting! I'll take a look 👀

[vojtabohm]

Thank you for such a quick fix, man! 🫡

[vojtabohm]

Could I ask, how can I try-catch this in my codebase? I am trying to wrap the entire EventSource creation + callback setup in a try catch but when this library fails (reading .status on a null object) it still is thrown as a runtime exception and I cannot gracefully fail in the UI.

@mpetazzoni

[mpetazzoni]

You might be able to do that with https://developer.mozilla.org/en-US/docs/Web/API/Window/error_event ?

[vojtabohm]

You're right, I am able to catch it with that :) Thanks! Now it's about stopping the propagation inside Electron so it doesn't appear to the user. But I understand this is out of scope of this repo. If anyone knows how to do this, please let me know.