Skip to content
lamina

fetch-failed

All codes

  • Type: error
  • Kind: io (the host failed to supply bytes; often transient)

What happened

A range source of @lamina/pdf (httpRangeSource) couldn’t get bytes it asked for: the request failed (network error, CORS refusal, DNS) or the server answered with a status other than 200 or 206, or with a 206 whose Content-Range (or length) doesn’t match the range asked for: a Content-Range the browser hides because CORS doesn’t expose it looks the same. It is also raised when a callbackSource’s read returns a different number of bytes than it was asked for.

Why

Opening a remote file range by range depends on the server: it must allow the Range request (and, across origins, expose Content-Range, Content-Length and ETag through CORS), and must not compress the response (Content-Encoding breaks byte ranges). lamina never retries on its own; the error says the bytes are not available.

How to fix

Check that the URL is reachable from where the code runs and that the server sends Access-Control-Allow-Origin, Access-Control-Allow-Headers: Range and Access-Control-Expose-Headers: Content-Range, Content-Length, ETag. Serve PDFs without Content-Encoding. Retry the call yourself if the failure was transient.

Example

const doc = await Document.openRange(httpRangeSource(url)); // throws { code: "fetch-failed", data: { status: 403 } }

Data fields

  • reason: network, status, content-range or length (lamina’s own words). The URL is never included.
  • status: the HTTP status, when there was a response.
  • expected, got: for length, the bytes asked for and the bytes returned.