fix: support Connection header with connection-specific header names per RFC 7230 #4775
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…per RFC 7230 Per RFC 7230 Section 6.1, the Connection header can contain a comma-separated list of connection option tokens (header names) that should be removed by proxies before forwarding the message. Previously, undici only allowed 'close' or 'keep-alive' as Connection header values. This change allows any valid HTTP token as a connection option, enabling RFC-compliant requests like: Connection: X-Custom-Header Connection: close, X-Custom-Header Fixes: #4774 Signed-off-by: Matteo Collina <hello@matteocollina.com>
metcoder95
reviewed
Jan 27, 2026
lib/core/request.js
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| if (value === 'close') { | ||
| const tokens = value.split(',').map(t => t.trim().toLowerCase()) |
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We are iterating over them twice, can we do it at one pass?
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You could actually lowercase before split.
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Done! Refactored to lowercase before split and combined validation + close-check in a single loop.
- Lowercase before split as suggested - Combine validation and close-check in single loop Signed-off-by: Matteo Collina <hello@matteocollina.com>
The previous test used 'asd' as an invalid connection header value, but 'asd' is a valid HTTP token per RFC 7230. Updated to use a truly invalid value (token with spaces) instead. Signed-off-by: Matteo Collina <hello@matteocollina.com>
Codecov Report✅ All modified and coverable lines are covered by tests. Additional details and impacted files@@ Coverage Diff @@
## main #4775 +/- ##
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- Coverage 93.27% 93.26% -0.02%
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Files 109 109
Lines 34001 34009 +8
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+ Hits 31713 31717 +4
- Misses 2288 2292 +4 ☔ View full report in Codecov by Sentry. 🚀 New features to boost your workflow:
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metcoder95
approved these changes
Jan 29, 2026
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Summary
closeorkeep-alivewere accepted, now any valid HTTP token is allowedrequest.reset = trueifcloseis present in the token listTest plan
closeandkeep-alivevaluesFixes #4774