This relates to...

interceptors.decompress() currently attempts to initialize a decoder for HEAD responses when the server includes a supported Content-Encoding.

Because a valid HEAD response contains no response body, the decoder receives no compressed data and response.body.text() rejects with:

Z_BUF_ERROR: unexpected end of file

The interceptor also removes Content-Encoding and Content-Length, even though those headers describe the corresponding GET representation and are valid metadata on a HEAD response.

Rationale

HTTP HEAD responses must not include response content, but their representation headers describe the response that would have been returned for a corresponding GET.

Undici’s Fetch implementation already skips response decoding for HEAD. The decompression interceptor should do the same rather than creating an empty decoder and removing representation metadata.

Changes

Features

N/A

Bug Fixes

• Bypass the decompression interceptor for HEAD requests.
• Preserve Content-Encoding and Content-Length on encoded HEAD responses.
• Ensure the response body resolves to an empty string instead of rejecting with Z_BUF_ERROR.
• Add a public API regression test using Client.compose(interceptors.decompress()).

Breaking Changes and Deprecations

None.

Testing

node --test test/interceptors/decompress.js
npm run test:interceptors
npm run lint

Status

• I have read and agreed to the Developer's Certificate of Origin
• Tested
• Benchmarked (optional)
• Documented
• Review ready
• In review
• Merge ready