Files
hyperframes/packages/core
Miguel Angel Simon Sierra b2ef6192ed fix(media-use): replace regex SVG sanitizer with a DOM allowlist
Two rounds of regex/tokenizer patches to sanitizeSvg found new bypasses
in the same shape each time (unquoted href, style= url(), aliased
xlink prefix; then presentation-attribute url(), unquoted '=' handling,
SMIL animate/set href rewrite, self-closing-slash tag corruption,
data:image/ navigation via <a>). Denylisting attribute names against a
hand-rolled tokenizer was the wrong approach regardless of how careful
the regex.

Rewrote sanitizeSvg (packages/core/src/figma/sanitizeSvg.ts) as a real
DOM walk (linkedom, already a dependency of core and cli) with an
allowlist: known-safe elements and attributes only, everything else
dropped by construction rather than pattern-matched as dangerous.
href/xlink:href (any namespace prefix) kept only for a same-document
fragment, or data:image/ off non-<a> elements. Any attribute value or
<style> text containing url() kept only when every url() argument is a
fragment; @import/expression(/javascript: dropped from style content.
Serializing from a real DOM means output is always well-formed, so the
self-closing-slash corruption class of bug is gone by construction.

media-use's own copy (packages/cli/src/media-use/lib/svg-sanitize.mjs)
can't import linkedom directly: its CI test lane runs bare `node --test`
with no install step, so even an external dependency fails to resolve,
not just a workspace import. It's now a generated file instead of a
hand-copy: scripts/generate-media-use-svg-sanitize.mjs bundles the core
source (esbuild, minified, zero remaining imports) and
scripts/check-media-use-svg-sanitize-generated.test.mjs fails the build
on drift. Verified the generated file runs with plain node in an empty
directory with no node_modules on the path.

Every payload from both independent-review reports is now a
table-driven test in sanitizeSvg.test.ts (46 cases) and the same corpus
in check-svg-sanitize-parity.test.mjs (39 cases) asserts core and the
generated media-use copy agree and each independently rejects every
non-local url(), javascript:, data: href on <a>, and on* handler.
Mutation-proved against the real pre-fix blob, not a synthetic case.

Sampled 56 real theSVG icons across all 7 collections to check the
allowlist doesn't over-strip legitimate content: found and fixed three
missing attributes (fx/fy, enable-background, a blanket data-*
allowance) and one real behavioral bug - <style> elements were being
dropped outright, silently unstyling any Illustrator-exported logo that
colors paths via CSS classes. Fixed by keeping <style> on the allowlist
and content-checking its text the same way as an inline style=
attribute, with a regression test using that exact shape.

Full suite after the fix: sanitizeSvg.test.ts 46/46, parity+drift tests
39/39, media-use suite 298/298, tsc/oxlint/oxfmt clean.
2026-09-23 02:09:49 -04:00
..

@hyperframes/core

Types, parsers, generators, compiler, linter, runtime, and frame adapters for the Hyperframes video framework.

Install

npm install @hyperframes/core

Most users don't need to install core directly — the CLI, producer, and studio packages depend on it internally.

What's inside

Module Description
Types TimelineElement, CompositionSpec, Asset, canvas dimensions, defaults
Parsers parseHtml — extract timeline elements from HTML; parseGsapScript — parse GSAP animations
Generators generateHyperframesHtml — produce valid Hyperframes HTML from a composition spec
Compiler compileTimingAttrs — resolve data-start / data-duration into absolute times
Linter lintHyperframeHtml — validate Hyperframes HTML (missing attributes, overlapping tracks, etc.)
Runtime IIFE script injected into the browser — manages seek, media playback, and the window.__hf protocol
Frame Adapters Pluggable animation drivers (GSAP, Lottie, CSS, or custom)

Generated composition trust

Composition generators require trusted authors for code-bearing inputs. styles and generateHyperframesStyles preserve authored CSS, which can load external resources. animations may contain __raw: values that are emitted as JavaScript; includeScripts: true includes executable timeline code. serializeGsapAnimations also accepts raw preamble, postamble, and a code-bearing timelineVar. Never fill these inputs with untrusted data. Attribute encoding and closing-tag containment are not a sandbox; render untrusted compositions in an appropriately isolated execution environment and never serve them on a privileged origin.

Text content retains the supported inline-formatting sanitizer contract. The clip parser intentionally flattens inner formatting to text, so parse/generate is not a lossless replacement for editing the source HTML.

Frame Adapters

A frame adapter tells the engine how to seek your animation to a specific frame:

import { createGSAPFrameAdapter } from "@hyperframes/core";

const adapter = createGSAPFrameAdapter({
  getTimeline: () => gsap.timeline(),
  compositionId: "my-video",
});

Implement FrameAdapter for custom animation runtimes:

import type { FrameAdapter } from "@hyperframes/core";

const myAdapter: FrameAdapter = {
  id: "my-adapter",
  getDurationFrames: () => 300,
  seekFrame: (frame) => {
    /* seek your animation */
  },
};

Parsing and generating HTML

import { parseHtml, generateHyperframesHtml } from "@hyperframes/core";

const { elements, metadata } = parseHtml(htmlString);
const html = generateHyperframesHtml(spec);

Linting

import { lintHyperframeHtml } from "@hyperframes/core/lint";

const result = lintHyperframeHtml(htmlString);
// result.findings: { severity, message, elementId }[]

Documentation

Full documentation: hyperframes.heygen.com/packages/core