Should HTTP 400+ be considered errors?

[DavidBruant]

The current d3.json function would not consider a 404 or a 500 an error, but doesn't forward the status code to verify it either. This might lead to hard-to-debug code.

Happy to send a PR if there is consensus

[mbostock]

Yes, this is a bug; we should check the response status code. If people want to parse the responses for non-success status codes, it should be reasonable for them to just use the Fetch API directly (since this module is already a very thin layer on top of fetch).

The logic in d3-request was something like:

if (!status && hasResponse(xhr)
    || status >= 200 && status < 300
    || status === 304) {
  …
}

I think what we want in d3-fetch is to check response.ok.

[DavidBruant]

<3

[mbostock]

Fixed in 1.0.1. Thanks for the feedback!