fix(mock): preserve fetch FormData boundary on net-connect fallback#5262
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SAY-5 wants to merge 2 commits intonodejs:mainfrom
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fix(mock): preserve fetch FormData boundary on net-connect fallback#5262SAY-5 wants to merge 2 commits intonodejs:mainfrom
SAY-5 wants to merge 2 commits intonodejs:mainfrom
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When MockAgent is active, fetch sends request.body.source so body matchers see the original input. For FormData sources, the dispatcher then re-extracts the body via extractBody() and generates a fresh multipart boundary, while the content-type header retains the boundary fetch produced earlier. Servers that consult content-type and the body's leading boundary line see a mismatch. Skip the source override for FormData and dispatch the prepared async iterator instead. Source matching against FormData was not usable through matchValue anyway. Fixes nodejs#5241 Signed-off-by: SAY-5 <saiasish.cnp@gmail.com> Signed-off-by: Sai Asish Y <saiasish.cnp@gmail.com>
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| req.on('data', (c) => chunks.push(c)) | ||
| req.on('end', () => { | ||
| const body = Buffer.concat(chunks).toString('utf8') | ||
| const headerMatch = /boundary=(.+)$/.exec(req.headers['content-type'] || '') |
Codecov Report✅ All modified and coverable lines are covered by tests. Additional details and impacted files@@ Coverage Diff @@
## main #5262 +/- ##
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Coverage 93.27% 93.28%
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Files 110 110
Lines 36366 36391 +25
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+ Hits 33922 33946 +24
- Misses 2444 2445 +1 ☔ View full report in Codecov by Sentry. 🚀 New features to boost your workflow:
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metcoder95
reviewed
May 7, 2026
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FYI the only failing checks are pre-existing flakes unrelated to this PR's MockAgent FormData change:
main branch has had similar failures during this window. Happy to rebase if a maintainer would like a re-run. |
SAY-5
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This relates to...
Fixes #5241
Rationale
When fetch sends a
FormDatabody through aMockAgentthat falls through to net connect, mock body matching wants the original request source, but the real dispatch path must keep fetch's already-encoded body so the multipart boundary stays aligned with thecontent-typeheader.Changes
request.body.source || request.body.streampath for MockAgent requests.FormDatarequest misses the mock intercept and passes through to the original dispatcher.Features
N/A
Bug Fixes
Breaking Changes and Deprecations
N/A
Status