fix: revive dead FormData Content-Type warning (#6067)#6070
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harrishancock merged 3 commits intomainfrom Feb 13, 2026
Merged
fix: revive dead FormData Content-Type warning (#6067)#6070harrishancock merged 3 commits intomainfrom
harrishancock merged 3 commits intomainfrom
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harrishancock
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Feb 13, 2026
jasnell
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Feb 13, 2026
jasnell
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Feb 13, 2026
jasnell
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jasnell
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The logWarning() in Body::Body that warns when a FormData body is paired with a custom Content-Type header was dead code. The comparison used ConstMimeType::operator==(kj::StringPtr), which compared the full substring after '/' against the subtype -- so 'form-data; boundary=...' never matched 'form-data'. Fix the comparison by parsing the content-type string into a MimeType first, then comparing against MimeType::FORM_DATA. The MimeType equality operator correctly ignores MIME parameters like boundary. Also remove ConstMimeType::operator==(kj::StringPtr) entirely -- it was a footgun with only this one (buggy) caller, and any future use would hit the same parameter-ignoring trap. Co-Authored-By: Claude <noreply@anthropic.com>
Several logWarning() call sites were guarded by isInspectorEnabled(), which only returns true when the Chrome DevTools inspector is connected. This meant warnings were silently dropped for streaming tail workers and --verbose stderr logging. Add IoContext::hasWarningHandler() that returns true if the inspector, a streaming tail worker tracer, OR --verbose logging is active. Replace all isInspectorEnabled() guards on warning paths with hasWarningHandler(). Co-Authored-By: Claude <noreply@anthropic.com>
Add a two-worker test that exercises several logWarning() code paths and verifies the warnings are visible to a streaming tail worker: - FormData body with a custom Content-Type header (Body::Body) - Null-body status with zero-length body (Response constructor) The "trigger" worker generates warnings in its fetch() handler, invoked via a service binding from its test() entrypoint. The "tail" worker collects streaming tail events and asserts that all expected warning substrings appear within a polling timeout. Co-Authored-By: Claude <noreply@anthropic.com>
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harrishancock
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jasnell
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The
logWarning()inBody::Bodythat warns when aFormDatabody is paired with a custom Content-Type header was dead code. The comparison usedConstMimeType::operator==(kj::StringPtr), which compared the full substring after '/' against the subtype — so 'form-data; boundary=...' never matched 'form-data'.Fix the comparison by parsing the content-type string into a
MimeTypefirst, then comparing againstMimeType::FORM_DATA. TheMimeTypeequality operator correctly ignores MIME parameters like boundary.Also remove
ConstMimeType::operator==(kj::StringPtr)entirely — it was a footgun with only this one (buggy) caller, and any future use would hit the same parameter-ignoring trap.Add a streaming tail worker test that verifies the warning is emitted and captured in the tracing system when a Request is constructed with a
FormDatabody and a custom Content-Type header.Fixes #6067