Keep cold Candidate verification cooperative with controller renewals

test/evolution.test.ts

@@ -3,6 +3,7 @@ import { test } from "node:test";
 import { capabilityId as id, valueType, validateWorkspaceRevision } from "../src/capability-model/index.js";
 import {
   contentDigest,
+  contentDigestAsync,
   planEvolution,
   reviewSemanticMajors,
   runtimeContracts,
@@ -51,6 +52,27 @@ test("hashing is canonical and rejects values outside the persisted JSON contrac
   assert.throws(() => contentDigest(new Date()));
 });
 
+test("cooperative hashing preserves canonical identities and services the event loop", async () => {
+  const sparse = [1, 2, 3];
+  delete sparse[1];
+  const values = [null, false, -0, "中\\n\ud800", sparse, { z: 1, a: { omitted: undefined, b: [false, 1e100] } }];
+  for (const value of values) assert.equal(await contentDigestAsync(value), contentDigest(value));
+  for (const value of [undefined, NaN, Infinity, new Date(), [undefined]])
+    await assert.rejects(contentDigestAsync(value));
+  const large = Array.from({ length: 50000 }, (_, index) => ({ z: "definition".repeat(8), a: index }));
+  const expected = contentDigest(large);
+  let serviced = false;
+  const timer = setTimeout(() => {
+    serviced = true;
+  }, 0);
+  try {
+    assert.equal(await contentDigestAsync(large), expected);
+    assert.equal(serviced, true, "large verification must let host renewals and RPCs run");
+  } finally {
+    clearTimeout(timer);
+  }
+});
+
 test("a workspace root change and display names do not restart package runtimes", () => {
   const before = makeValidCapabilityWorkspace();
   const after = structuredClone(before);