test: add proposal w/300 E(chainTimerService).getTimerBrand() calls (#…

…10696)

## Description

@warner asked for a proposal that would ensure there were several more (300 was settled on) arbitrary calls in order to provoke bring-out-your-dead.

### Security Considerations

test environments only: aimed at mainFork.

### Scaling Considerations

No implications

### Documentation Considerations

Unnecessary

### Testing Considerations

For test environments.

### Upgrade Considerations

None.

packages/builders/scripts/testing/provokeBOYD.js

@@ -0,0 +1,54 @@
+/**
+ * @file call getTimerBrand() 300 times in hopes of provoking BOYD. This is
+ * intended for tests on mainFork for upgrade-18. If there's a similar need in
+ * other tests, it can be included there as well. There would be no value in
+ * including it in an upgrade of MainNet; it just spins cycles to provoke
+ * garbage collection.
+ */
+
+import { makeTracer } from '@agoric/internal';
+import { E } from '@endo/far';
+
+/// <reference types="@agoric/vats/src/core/types-ambient"/>
+/** @import {Instance} from '@agoric/zoe/src/zoeService/utils.js'; */
+
+const trace = makeTracer('provokeBOYD', true);
+
+/**
+ * @param {BootstrapPowers} powers
+ */
+export const provokeBOYD = async ({ consume: { chainTimerService } }) => {
+  trace(provokeBOYD.name);
+  await null;
+
+  for (let i = 0; i < 300; i += 1) {
+    await E(chainTimerService).getTimerBrand();
+  }
+  trace('done');
+};
+harden(provokeBOYD);
+
+export const getManifestForProvokeBOYD = () => {
+  return {
+    manifest: {
+      [provokeBOYD.name]: {
+        consume: { chainTimerService: true },
+      },
+    },
+  };
+};
+
+/** @type {import('@agoric/deploy-script-support/src/externalTypes.js').CoreEvalBuilder} */
+export const defaultProposalBuilder = async () =>
+  harden({
+    sourceSpec: '@agoric/builders/scripts/testing/provokeBOYD.js',
+    getManifestCall: ['getManifestForProvokeBOYD'],
+  });
+
+/** @type {import('@agoric/deploy-script-support/src/externalTypes.js').DeployScriptFunction} */
+export default async (homeP, endowments) => {
+  const dspModule = await import('@agoric/deploy-script-support');
+  const { makeHelpers } = dspModule;
+  const { writeCoreEval } = await makeHelpers(homeP, endowments);
+  await writeCoreEval(provokeBOYD.name, defaultProposalBuilder);
+};