test(electron): cover renderer recovery policy

packages/electron/renderer-recovery.mjs

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+const RECOVERY_WINDOW_MS = 60_000;
+const MAX_RECOVERY_ATTEMPTS = 3;
+
+const RECOVERABLE_REASONS = new Set([
+  'abnormal-exit',
+  'crashed',
+  'oom',
+  'memory-eviction',
+]);
+
+export const createRendererRecoveryPolicy = (now = Date.now) => {
+  let windowStartedAt = 0;
+  let attempts = 0;
+
+  return {
+    shouldReload: (reason) => {
+      if (!RECOVERABLE_REASONS.has(reason)) return false;
+
+      const currentTime = now();
+      if (currentTime - windowStartedAt >= RECOVERY_WINDOW_MS) {
+        windowStartedAt = currentTime;
+        attempts = 0;
+      }
+      if (attempts >= MAX_RECOVERY_ATTEMPTS) return false;
+
+      attempts += 1;
+      return true;
+    },
+  };
+};

packages/electron/renderer-recovery.test.mjs

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+import assert from 'node:assert/strict';
+import test from 'node:test';
+
+import { createRendererRecoveryPolicy } from './renderer-recovery.mjs';
+
+test('allows a bounded number of reloads for recoverable renderer failures', () => {
+  const policy = createRendererRecoveryPolicy(() => 1_000);
+
+  assert.equal(policy.shouldReload('crashed'), true);
+  assert.equal(policy.shouldReload('oom'), true);
+  assert.equal(policy.shouldReload('abnormal-exit'), true);
+  assert.equal(policy.shouldReload('memory-eviction'), false);
+});
+
+test('ignores clean and externally killed renderer exits', () => {
+  const policy = createRendererRecoveryPolicy(() => 1_000);
+
+  assert.equal(policy.shouldReload('clean-exit'), false);
+  assert.equal(policy.shouldReload('killed'), false);
+  assert.equal(policy.shouldReload('launch-failed'), false);
+});
+
+test('resets the recovery budget after the recovery window', () => {
+  let currentTime = 1_000;
+  const policy = createRendererRecoveryPolicy(() => currentTime);
+
+  assert.equal(policy.shouldReload('crashed'), true);
+  assert.equal(policy.shouldReload('crashed'), true);
+  assert.equal(policy.shouldReload('crashed'), true);
+  assert.equal(policy.shouldReload('crashed'), false);
+
+  currentTime += 60_000;
+  assert.equal(policy.shouldReload('crashed'), true);
+});