Reject invalid Act outcome payloads

bin/aas.mjs

@@ -208,7 +208,12 @@ export function runAct(
     cwd: join(depsDir, "consequence-rail"),
   });
   if (result.status !== 0) throw childProcessError("act", result);
-  return { ok: true, raw: parseJsonOutput(result.stdout, "act"), status: 0 };
+  const payload = parseJsonOutput(result.stdout, "act");
+  if (!payload || typeof payload !== "object" || Array.isArray(payload)
+    || ![null, "settled", "compensated", "disputed"].includes(payload.outcome)) {
+    throw new Error("act did not return a valid outcome");
+  }
+  return { ok: true, raw: payload, status: 0 };
 }
 
 export function runProve(

test/stack.test.mjs

@@ -8,6 +8,7 @@ import { loadComponentLock, inspectDependencyDirectory, npmInvocation } from "..
 import {
   persistRunBundle,
   resolveComponentProvenance,
+  runAct,
   runDemo,
   writeAtomicFile,
 } from "../bin/aas.mjs";
@@ -128,6 +129,16 @@ test("Windows npm commands run through the npm JavaScript entrypoint", () => {
   );
 });
 
+test("act rejects a zero-exit payload without a valid outcome", () => {
+  assert.throws(
+    () => runAct("none", {
+      depsDir: tempRoot(),
+      runner: () => ({ status: 0, stdout: "{}\n", stderr: "", error: null }),
+    }),
+    /valid outcome/,
+  );
+});
+
 test("pass bundle contains stage status, provenance, and only current artifacts", async () => {
   const outputRoot = tempRoot();
   const result = await runDemo(["--response", "pass"], stubOptions(outputRoot, { runId: "pass-run" }));