Multipart and binary qualification

Historical baseline: verified implementation. Results below apply only to this baseline and the recorded environment; they are not a statement of current support or release status.

See the media follow-up for the subsequent changes.

Local verification: 2026-09-20 (Asia/Shanghai), macOS arm64, Node 24.16.0, pnpm 10.34.5. No remote publication was performed.

ChangesCopy Anchor Link

• Retain File names when replacing multipart part media types.
• Preserve explicit text media parameters and reject unsupported generated charsets.
• Resolve multipart media ranges from concrete Blob/File types.
• Accept binary views in core without widening their byte ranges.
• Verify multipart and binary fidelity through installed HTTP consumers and Chromium.

Verified locallyCopy Anchor Link

• pnpm check passed: format, typed lint, generated fixtures, TypeScript, coverage, build, publint, attw, installed-package consumers and type budgets.
• 319 tests passed across 28 files. Coverage: statements 95.98%, branches 94.05%, functions 98.08%, lines 97.05%.
• Core transitive gzip is 1974 / 2048 bytes; the budget was not increased.
• Multipart tests preserve filenames for matching, differing and empty File types, retain repeated file parts, reject unsupported text charsets before transport, check UTF-8 and pre-encoded non-UTF-8 bytes, select per-file concrete types and reject missing/mismatched/wildcard type evidence.
• Core and strict binary tests verify Uint8Array, DataView and Node Buffer slices send only the selected bytes.
• Installed-package real HTTP checks inspect part headers, original filenames, textual/binary payload bytes and core binary slices from the packed public API.
• Chromium real HTTP checks verify per-file image range selection, filenames, explicit UTF-8 part headers, Unicode text and binary slices, alongside existing CORS, cookies, cancellation and streaming checks.

Versioned package rehearsalCopy Anchor Link

A temporary source copy with pending Changesets generated version 0.1.0 and its changelog, updated the lockfile with lifecycle scripts disabled, built all public entries and passed pnpm test:package. The 31-file openapi-chain-0.1.0.tgz passed installed ESM/CJS, generated NodeNext and real HTTP consumer checks, including the new multipart assertions. The rehearsal reused local development dependencies and did not consume the working repository's Changesets.

BoundariesCopy Anchor Link

See binary and multipart support. Generated text uses UTF-8; other encodings require pre-encoded bytes or a whole-body extension. Parameterized text parts use native Blob-backed FormData parts, which include a filename. Parameterized media ranges and multiple choices require application serialization. These changes do not add arbitrary MIME generation, request streaming defaults or complete JSON Schema validation.

Remote Node/OS matrix results, npm OIDC configuration, published provenance and registry-installed consumers remain unverified for this baseline. After push/publication authorization, run the existing gated release workflow and verify those results against the exact published version. Local qualification and a version rehearsal do not establish public delivery.