notify callback parameters name are confusing

Describe the bug

When calling bugnsag.notify, I pass a a callback to add metadata. These pieces of metadata don’t seem to be sent to bugsnag. Stepping through teh code, it looks like they should be getting added, though printing the event object at the end of the callback shows that they were not.

Steps to reproduce

in a react native app add:

 captureError(params: CaptureErrorParams): void {
    const { error, message, extra, sendToServer } = params;

    const addMessageAsContext: (error: any, event: Event) => void = (
      _error,
      event
    ) => {
      event.context = message;

      //convert the dictionary into metadata
      if (params.extra != null) {
        for (const [sectionKey, sectionData] of Object.entries(params.extra)) {
          for (const [key, value] of Object.entries(sectionData)) {
            event.addMetadata(sectionKey, key, value);
          }
        }
      }

      //eslint-disable-next-line no-console
      console.log('callback: ', event.getMetadata('great'));   <======prints undefined
    };

 this.bugsnagClient.notify(
          JSON.stringify(error),
          undefined,
          addMessageAsContext
        );
}


    captureError({
      message: 'message',
      error: new Error('error name'),
      extra: { great: { details: 'detailed answer' } },
    });

I stepped through addMetadata and it seems that state[section] = assign({}, state[section], updates) has no effect. I added console.log(state) right after it and it still has the original content, no trace of the extra metadata: {"app": {"name": "xxx"}, "device": {"simulator": true, "thermalState": "nominal", "timezone": "GMT+1", "wordSize": 64}}

Environment

• Bugsnag version: “@bugsnag/react-native”: “^7.16.0”,
• Browser framework version (if any):
  • React:“react”: “17.0.2”,
• Device (e.g. iphonex): simulator

[otusweb]

Thanks for clarifying @imjoehaines . It’s a case of not understanding the parameter’s names on my end then.

I understood onError to be a callback called when an error was thrown while sending the event to the server. cb just did not mean anything to me, so I used it.

Can I suggest renaming those parameters:

• onReadyToSend instead of onError, or anything that relates that it is called before the event is sent to offer configuration opportunity
• onSent instead of cb or anything that indicates this is called when the event has been sent

Thanks for helping me figure it out

[imjoehaines]

Hey @otusweb, there are two different kinds of callbacks that notify accepts:

• onError is a callback that runs before sending the event to Bugsnag, so you can make changes to the event. This is explained here in the docs
• cb is a callback that runs when the event has been enqueued for delivery, so it’s too late to change the event here. The documentation for this is in the JS docs

Generally you’ll want to use the onError callback as it allows you to make changes to the event before sending it

I hope that clears things up!