Files
hyperframes/packages
JamesandClaude Opus 4.7 bd5c489eec feat(producer): fail-closed font fetch flag in deterministicFonts
Part of Phase 2 of the distributed rendering plan (determinism hardening).
See DISTRIBUTED-RENDERING-PLAN.md §5.3 (banned in distributed mode) and
§9.3 (typed non-retryable failures).

Today `injectDeterministicFontFaces(html)` swallows external font-fetch
failures: a failed Google Fonts CSS request or woff2 download returns
empty arrays, the composition warns via `warnUnresolvedFonts`, and Chrome
falls back to system fonts. That fallback would silently desync chunk
workers in distributed mode (workers run in a Linux container that
doesn't have macOS / Windows system fonts), so distributed renders need
to fail closed.

This change adds an options bag to `injectDeterministicFontFaces`:

  injectDeterministicFontFaces(html, {
    failClosedFontFetch?: boolean;  // default false
    fetchImpl?: typeof fetch;       // default global fetch
  })

When `failClosedFontFetch === true`, any non-OK CSS response, any non-OK
woff2 response, and any network error during either fetch throws a typed
`FontFetchError` with `code === FONT_FETCH_FAILED`. When `false` (the
default), behavior is unchanged.

`fetchImpl` lets unit tests inject failing-fetch stubs without going over
the network.

The in-process caller (`htmlCompiler.ts`) continues to call
`injectDeterministicFontFaces(html)` without options and gets the legacy
behavior. Phase 3's `plan()` will pass `failClosedFontFetch: true`.

Producer regression baselines remain byte-identical: no caller flips the
flag.

10 unit tests at packages/producer/src/services/
deterministicFonts-failClosed.test.ts pin both branches (default
swallows network error / 404; locked throws FontFetchError with correct
code, URL, and family name) plus the "no fetch happens for bundled
fonts" carve-out.

This is part of a stack of 10 PRs; this is PR 10 of 10.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-13 04:36:12 +00:00
..
2026-05-13 01:35:21 +00:00
2026-05-13 01:35:21 +00:00