Field signal ts=1784039841 (win32/x64, CLI 0.7.57): shifted-DOM-image-
layer bug at frame 120 reproduces with BOTH PRODUCER_FORCE_SCREENSHOT=true
AND HF_DE_PARALLEL_ROUTER=false set. First case where both known escape
hatches fail simultaneously. Standalone 1920x1080 GSAP paused timeline,
absolute PNG layers, 4 independent scenes.
Ships a skipped regression fixture to codify the shape. NOT a fix — no
root cause identified. The composition is preserved so a future
diagnostic pass has a real, checked-in repro and a proposed fix can be
validated against the same shape the field reported.
Skip mechanism (belt-and-suspenders):
1. meta.json tagged `field-signal-reproducer` and `known-broken`;
producer/package.json test:regression* scripts add the tag to
--exclude-tags alongside the existing `transparency` skip.
2. Not registered in any .github/workflows/regression.yml shard's
args, so the CI regression sweep won't pick it up either.
Un-skip when a fix lands: drop the tags from meta.json AND add the
fixture id to a shard's args in the workflow. See src/README.md for
the field-signal envelope and diagnostic starting points.
Stack: PR #8 of 9 (base via/gpu-parity-gate).
Signed-off-by: Via
canvas.drawElementImage is an unlaunched Dev/Canary-only Blink feature
(~151+). The CLI's pinned CHROME_VERSION fallback was still 131.0.6778.85 —
a puppeteer 24→25.2.1 bump that pinned it to Chrome Dev 151.0.7912.0 was
written on 2026-06-29 but never merged (orphaned local commit, no PR). Any
render on that pin, or on the shared puppeteer-cache binary, or on system
Chrome (Stable, no drawElementImage at all) got a canvas.getContext("2d")
missing the method and crashed mid-capture with "ctx.drawElementImage is
not a function" instead of falling back (HF#2060).
Three changes:
- Bump puppeteer/puppeteer-core to ^25.2.1 across every package that
depends on it, and CHROME_VERSION to 152.0.7928.2 (today's Dev channel;
confirmed via direct probe to implement drawElementImage, unlike 131).
- `ensureBrowser({ preferManagedChrome: true })`, always used by `render`:
resolve straight to our pinned/cached build, skipping both the shared
puppeteer-cache preference and system Chrome. Rendering shouldn't depend
on whatever arbitrary Chrome a machine happens to have — that's exactly
how this regressed (any Mac with Chrome.app installed bypassed the CLI's
pin entirely).
- A runtime capability probe in the engine, right before any other
drawElement work: if `drawElementImage` isn't a function on the injected
canvas, route to the existing screenshot-fallback gate instead of
crashing. This is the real backstop — it protects every resolution path
(env override, stale cache entry, a future Chrome regression), not just
the ones `preferManagedChrome` reaches.
Verified end-to-end: rendering against chrome-headless-shell 131 (confirmed
to lack drawElementImage) now falls back cleanly and produces a valid MP4
instead of crashing; rendering against a capable build still engages
drawElement normally. 922 engine tests + 1373 CLI tests pass.
Fixes#2060.
* fix(core,producer,cli): pre-flight validation for empty/malformed sub-compositions
The #1 render failure bucket in production telemetry (PostHog project 356858,
dashboard 1783183 "HyperFrames — Bottom-Line & Activation"; ~65-69K
occurrences / ~27-28K affected users over 30 days, ~80% via AI-agent
authoring flows) is a `data-composition-src` reference pointing at a scene
file that is empty, malformed, or missing.
Root cause, traced end-to-end:
- The literal error "Composition HTML is empty or could not be parsed: <path>"
is real (not a PostHog paraphrase) — thrown by a since-reverted guard in
packages/core/src/compiler/inlineSubCompositions.ts (#1364), then changed to
a silent skip in #1678 to avoid aborting renders on partial content during
authoring. #1629 added per-assembler guards for 3 skill workflows
(product-launch-video, faceless-explainer, pr-to-video), but general-video
and hand-authored flows — where the dominant filename `scene-title.html`
(40K+/68K of the bucket) originates — have no assembler and thus no guard.
#1678 assumed the assembler guards from #1629 covered this pre-render; they
only covered 3 of the many authoring flows.
- On current `main`, an empty/malformed data-composition-src file no longer
crashes or throws during render — it's silently dropped by the tolerant
inliner. Reproduced locally: `hyperframes render` on a project with an
empty scene-title.html "succeeds" after ~93s (two 45s
pollSubCompositionTimelines timeouts) with the scene silently missing from
the output video. `hyperframes validate` also reports "No console errors"
for the same broken project.
- The raw `Cannot destructure property 'firstElementChild' of
'documentElement' as it is null` crash reproduces directly against
linkedom (the DOMParser polyfill packages/cli/src/utils/dom.ts installs in
the real CLI runtime) for empty and non-HTML input — confirmed with a
standalone repro script, not just inferred. jsdom/happy-dom (used in this
repo's own test environment) are spec-compliant and never produce a null
documentElement, which is why this needed a linkedom-specific test file.
Fix:
- New shared helper `checkSubCompositionUsability`
(packages/core/src/compiler/subCompositionValidity.ts) is the single
source of truth for "is this data-composition-src file usable" — mirrors
the inliner's own parse/template/body logic so all callers agree.
- `inlineSubCompositions.ts` (preview/studio bundling) now uses the shared
helper internally but keeps its #1678 tolerant skip-and-continue behavior
unchanged — mid-authoring iteration on a partial project must keep
working. `onMissingComposition` now also receives a human-readable reason.
- New render-only pre-flight (`assertSubCompositionsUsable` in
packages/producer/src/services/htmlCompiler.ts) walks every
data-composition-src reference (including nested ones, root-relative,
matching parseSubCompositions' own resolution) before any compilation
work starts, and throws naming every offending file at once. This is
unconditional — not gated behind --strict — because a render that
silently drops a scene is strictly worse than one that refuses to start.
Confirmed locally: render now fails in ~0.4s with an actionable message
instead of "succeeding" after 93s with a missing scene.
- New `hyperframes lint` rule `missing_or_empty_sub_composition`
(packages/cli/src/utils/lintProject.ts) surfaces the same check as a
file-scoped, actionable lint error (already unconditional — lint exits 1
on any error).
- `hyperframes validate` now also runs this check before launching a
browser, so it no longer reports "No console errors" for a project with a
broken sub-composition.
- `packages/core/src/parsers/htmlParser.ts`: guarded every
`documentElement`-may-be-null access (parseHtml, updateElementInHtml,
addElementToHtml, removeElementFromHtml, extractCompositionMetadata,
validateCompositionHtml) with a new typed `CompositionHtmlParseError` (or,
for validateCompositionHtml's collect-and-report contract, a typed
validation failure) instead of a raw crash.
Tests: empty file, whitespace-only, malformed/non-HTML, missing file, nested
sub-compositions (both happy path and broken-grandchild), and the happy path
— at the shared-helper, lint, and render pre-flight layers.
Not changed: the AI-agent authoring skills (skills/*). general-video and
hand-authored flows have no assemble-index.mjs equivalent to guard, so the
fix is at the CLI/render layer instead — flow-agnostic, covers every
authoring path, and the skills' existing "run lint/validate and stop on
failure" guidance now actually catches this class of mistake once run.
Not run in this environment: the producer package's full regression-harness
test suite (`bun test` in packages/producer) — it performs heavy real
rendering (S3 asset downloads, Google Fonts fetches, full video encodes) and
did not complete in a reasonable time in this sandbox. Verified instead via
the targeted test file for all touched code (76/76 passing), whole-repo
typecheck/build/oxlint, `fallow audit` (complexity/duplication/dead-code
gate, clean), and manual end-to-end CLI runs (render/lint/validate) against
reproduction projects, including a nested sub-composition scenario. CI
should run the full producer suite before merge.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
* refactor(parsers,lint): port empty-composition pre-flight to extracted packages
Rebased onto main, which extracted @hyperframes/lint from core (lint depends
only on parsers, not core). Relocate checkSubCompositionUsability from core to
@hyperframes/parsers so both core (inliner) and lint can consume it without a
core<->lint cycle; core keeps a @deprecated re-export shim.
Correctness fixes from code review:
- checkSubCompositionUsability now returns "no-composition-root" when the
<template>/<body> content has no [data-composition-id] element (previously
a marker-free placeholder body passed both guards).
- lint's missing/empty sub-composition rule now only checks files reachable
via data-composition-src from the root (matching render pre-flight), instead
of a raw filesystem walk that false-positived on orphaned files.
- drop `as string` cast in inlineSubCompositions in favor of an explicit
null guard (per CLAUDE.md).
Review-comment items:
- move EmptyCompositionError JSDoc above the class (was above the adapter fn).
- correct stale circular-ref comment to match actual silent-skip behavior.
- rewrite self-contradicting lint message ("silently drop") to describe the
new loud render-pre-flight abort.
- add the __PLACEHOLDER__ (/^__[A-Z_]+__$/) skip to the render pre-flight so
it agrees with lint.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
---------
Co-authored-by: Claude Sonnet 5 <noreply@anthropic.com>
Miguel Ángel