[valeriangalliat]

🤖 AI agent: Arcade fork patch. Do not merge.

This draft shows patch/probe-untraced-media-src against main, the upstream mirror, so the patch has one page for its diff, its revisions and its reason. Arcade's /hyperframes-update rebases the branch onto main and cherry-picks it onto arcade; this PR is not part of that flow. When a rebuild changes the patch, its git range-diff against the previous sync/<date>/probe-untraced-media-src tag is posted as a comment.

Why

The renderer extracts video frames from the static src unless a trigger makes it load the page. hasRuntimeMediaChanges only follows src writes whose target it can resolve statically (getElementById or querySelector('<literal>')). A write in a loop, like root.querySelectorAll("[data-media-key]").forEach(el => { el.src = S[key]; }), was dropped by the parser, so a timed video exported its authored clip while preview played the swapped one.

The parser now keeps such writes with selector: null, and a null selector loads the page when the document has any <video> or <audio>. Lint skips null selectors, so its output is unchanged.

Untimed videos already load the page through the auto-start trigger, which is why this only shows with data-start.

Review notes

• MediaSrcMutation.selector becomes string | null in @hyperframes/parsers, a breaking type change for external consumers. Arcade doesn't import it.
• With media on the page, any untraced x.src = … loads the page, even one aimed at an <img> or a plain object. That costs time, not correctness.
• Still missed: external scripts, Object.assign(el, { src }), writes after a setTimeout.
• Arcade side: once this is pinned, the renderer uses URLs from scene settings JSON, which Arcade's pre-export alt=media repair doesn't cover yet. That repair needs extending before the pin ships.

Verification

• probeStage.test.ts 71/71, two new tests: a loop write with a video probes (fails without the source change), a loop write on images only doesn't.
• Lint media.test.ts 137/137. tsc, oxfmt, oxlint and lefthook clean.
• Arcade render corpus on prod's a318cd008 plus an earlier revision that included this change: 22/22. Corpus row setting-src-keyed-loop (ArcadeHQ/arcade#13159) fails on a318cd008 alone and passes with it.

Upstream

Issue filed: heygen-com/hyperframes#7504, with a repro. No upstream PR. Upstream may prefer teaching the parser the forEach shape over "unknown target means maybe"; the issue asks.

Drop when

Upstream probes media src writes it cannot resolve statically.

Arcade

ARC-17431 · ArcadeHQ/arcade#13159 · ArcadeHQ/arcade#13115

[github-actions]

Edit accuracy: accurate 271 (base branch 271), smooth 130 of those

The gate passes.
Smoothness is reported in the artifact, not gated. A case fails only if it fails 2 of 3 runs.

Quarantined, measured but not gated (0)

Unstable (1)

• seqplainkeys-none-pct-r0-nested-z100: tracking 0.05, pressJump 0, drop 0, reload 0, render 0.02, renderKey -, undo false, teleport true / tracking 0.05, pressJump 0, drop 0, reload 0, render 0.02, renderKey -, undo true, teleport true / tracking 0.05, pressJump 0, drop 0, reload 0, render 0.02, renderKey -, undo true, teleport true

[valeriangalliat]

🤖 AI agent: sync/2026-11-10: rebased onto upstream cda84222a (just past v0.9.30). Conflict in mediaSrcMutation.ts: upstream #5255 resolves write targets in their lexical scopes. The patch is re-applied on that parser. Upstream issue filed: heygen-com/hyperframes#7504.

1:  b2d2e5302 ! 1:  647ff8c70 fix(render): probe media src writes the parser cannot trace
    @@ packages/parsers/src/mediaSrcMutation.ts: import * as acorn from "acorn";
        operation: "src_assignment" | "set_attribute";
        raw: string;
      }
    -@@ packages/parsers/src/mediaSrcMutation.ts: function lookupSelector(node: any, bindings: ReadonlyMap<string, string>): strin
    +@@ packages/parsers/src/mediaSrcMutation.ts: function selectorFromDomLookup(
        return method === "getElementById" ? `#${value}` : value;
      }
      
    @@ packages/parsers/src/mediaSrcMutation.ts: function lookupSelector(node: any, bin
        try {
          const ast = parseProgram(script);
     @@ packages/parsers/src/mediaSrcMutation.ts: export function extractMediaSrcMutations(script: string): MediaSrcMutation[] {
    -     acornWalk.simple(ast, {
    -       AssignmentExpression(node: any) {
    -         if (node.operator !== "=" || memberName(node.left) !== "src") return;
    --        const selector = lookupSelector(node.left.object, bindings);
    +           memberName(node.left) !== "src"
    +         )
    +           return;
    +-        const selector = lookupSelector(node.left.object, scopeAt(ancestors));
     -        if (!selector) return;
              mutations.push({
     -          selector,
    -+          selector: lookupSelector(node.left.object, bindings) ?? null,
    ++          selector: lookupSelector(node.left.object, scopeAt(ancestors)) ?? null,
                operation: "src_assignment",
                raw: script.slice(node.start, node.end),
              });
     @@ packages/parsers/src/mediaSrcMutation.ts: export function extractMediaSrcMutations(script: string): MediaSrcMutation[] {
    -       CallExpression(node: any) {
    -         if (memberName(node.callee) !== "setAttribute") return;
    -         if (literalString(node.arguments?.[0])?.toLowerCase() !== "src") return;
    --        const selector = lookupSelector(node.callee.object, bindings);
    +         if (node.callee.type !== "MemberExpression" || memberName(node.callee) !== "setAttribute")
    +           return;
    +         if (literalString(node.arguments[0])?.toLowerCase() !== "src") return;
    +-        const selector = lookupSelector(node.callee.object, scopeAt(ancestors));
     -        if (!selector) return;
              mutations.push({
     -          selector,
    -+          selector: lookupSelector(node.callee.object, bindings) ?? null,
    ++          selector: lookupSelector(node.callee.object, scopeAt(ancestors)) ?? null,
                operation: "set_attribute",
                raw: script.slice(node.start, node.end),
              });