test(javascript): align semantic fixtures with runtime context

src/domain/javascript/javascriptStaticAnalysisReturnedInvocation.test.ts

@@ -168,7 +168,14 @@ it("retains a finite shared callable alias graph", () => {
     index.bindings,
     "direct-call",
   )(call.callee, call);
+  const declaration = parsed.program.body[0];
+  if (!t.isVariableDeclaration(declaration))
+    throw new Error("Expected root callable declaration");
+  const callable = declaration.declarations[0]?.init;
+  if (!t.isArrowFunctionExpression(callable))
+    throw new Error("Expected root arrow callable");
   expect(result).toEqual({
+    callables: new Set([callable]),
     references: [
       {
         node: expect.objectContaining({ type: "Identifier", name: "module" }),