Error-handling post-processing snippet

[bbenligiray]

The user wants a callback when the API call errors. We had this functionality, but it was removed at the design phase.

A simple way of emulating the same feature is having an error-handling post-processing step. Normally, when the API response is non-2XX, the Airnode always calls back fail(). We can have an errorHandlingPostProcessing snippet that only gets invoked when the API returns a non-2XX code and post-processes the API response to call back fulfill() with that.

[aTeoke]

@bbenligiray who is the user and what is the urgency please? Should it be ASAP or can be moved after 1.0 milestone? Thanks

[dcroote]

This was a user on discord. I would say low priority because the user themselves admitted / recognized "my use-case is very niche" and there are creative workarounds that @bbenligiray mentioned, like a proxy or FailedRequest watcher, that could suffice if the feature is badly needed.

[bbenligiray]

I think we should have this or something analogous at some point, but it shouldn't be included in our foreseeable plans. So I created the issue to document it for the future.