fix(core): route window.__hyperframes to the scoped variant in sub-comps

packages/core/src/compiler/compositionScoping.test.ts

@@ -79,6 +79,59 @@ body { margin: 0; }
     expect(fakeWindow.__captured).toEqual({ title: "Pro", price: "$29" });
   });
 
+  it("routes the documented window.__hyperframes.getVariables() to the scoped variant too", () => {
+    // Regression: the docs (variables-and-media.md) show `window.__hyperframes.
+    // getVariables()`, but inside a sub-comp the scoped `window` proxy used to
+    // fall through to the HOST page's base __hyperframes, returning the wrong
+    // (or empty) variables — the bare `__hyperframes` param was the only form
+    // that worked. Both spellings must now resolve to this comp's variables.
+    const { document } = parseHTML(`<div data-composition-id="card-1"></div>`);
+    const fakeWindow: Record<string, unknown> = {
+      document,
+      __timelines: {},
+      __hfVariablesByComp: {
+        "card-1": { title: "Pro", price: "$29" },
+        "card-2": { title: "Enterprise", price: "Custom" },
+      },
+      __hyperframes: {
+        getVariables: () => ({ title: "TOP-LEVEL-LEAK" }),
+        fitTextFontSize: () => undefined,
+      },
+    };
+    const wrapped = wrapScopedCompositionScript(
+      `window.__captured = window.__hyperframes.getVariables();`,
+      "card-1",
+    );
+
+    new Function("window", wrapped)(fakeWindow);
+
+    expect(fakeWindow.__captured).toEqual({ title: "Pro", price: "$29" });
+  });
+
+  it("preserves non-getVariables members on window.__hyperframes (only getVariables is rescoped)", () => {
+    const { document } = parseHTML(`<div data-composition-id="card-1"></div>`);
+    let fitCalled = false;
+    const fakeWindow: Record<string, unknown> = {
+      document,
+      __timelines: {},
+      __hfVariablesByComp: { "card-1": { title: "Pro" } },
+      __hyperframes: {
+        getVariables: () => ({ title: "TOP-LEVEL-LEAK" }),
+        fitTextFontSize: () => {
+          fitCalled = true;
+        },
+      },
+    };
+    const wrapped = wrapScopedCompositionScript(
+      `window.__hyperframes.fitTextFontSize();`,
+      "card-1",
+    );
+
+    new Function("window", wrapped)(fakeWindow);
+
+    expect(fitCalled).toBe(true);
+  });
+
   it("scoped getVariables reads from the runtime composition id when it differs", () => {
     const { document } = parseHTML(`<div data-composition-id="scene"></div>`);
     const fakeWindow: Record<string, unknown> = {

packages/core/src/compiler/compositionScoping.ts

@@ -396,6 +396,16 @@
     ? new Proxy(window, {
         get: function(target, prop, receiver) {
           if (prop === "__timelines") return __hfGetTimelineRegistry();
+          // Inside a sub-composition, __hyperframes is passed as a bare script
+          // param bound to the SCOPED variant (per-comp getVariables). But
+          // authors routinely write the documented window.__hyperframes.
+          // getVariables() form, which would otherwise fall through to the host
+          // page's base __hyperframes and return the WRONG (or empty) variables
+          // for this instance. Route it to the scoped variant too so both
+          // spellings resolve to this composition's own variables.
+          // (__hfScopedHyperframes is a hoisted var assigned below, before any
+          // sub-comp script -- the only code that reads this -- runs.)
+          if (prop === "__hyperframes") return __hfScopedHyperframes;
           return Reflect.get(target, prop, target);
         },
         set: function(target, prop, value, receiver) {
@@ -489,7 +499,7 @@
   var __hfBaseHyperframes = window.__hyperframes;
   var __hfScopedHyperframes = !__hfBaseHyperframes
     ? __hfBaseHyperframes
     : Object.assign({}, __hfBaseHyperframes, {
         getVariables: function() {
           var byComp = window.__hfVariablesByComp;
           var scoped = byComp && __hfTimelineCompId ? byComp[__hfTimelineCompId] : null;