Fail closed on invalid telemetry files

packages/storage/src/__tests__/telemetry-repo.test.ts

@@ -180,6 +180,22 @@ describe('FileTelemetryRepo', () => {
     }
   });
 
+  test('load accepts legacy telemetry files with only known array sections', async () => {
+    const root = await mkdtemp(join(tmpdir(), 'maka-telemetry-legacy-'));
+    try {
+      await writeFile(join(root, 'telemetry.json'), JSON.stringify({ usageRecords: [] }) + '\n', 'utf8');
+      const repo = createTelemetryRepo(root);
+
+      await repo.load();
+
+      assert.deepEqual(repo.logs({ range: 'all' }), { rows: [], total: 0 });
+      assert.deepEqual(repo.listPricingOverrides(), []);
+    } finally {
+      await flushWrites();
+      await rm(root, { recursive: true, force: true, maxRetries: 5, retryDelay: 20 });
+    }
+  });
+
   test('load rejects corrupt telemetry.json without overwriting usage history bytes', async () => {
     const root = await mkdtemp(join(tmpdir(), 'maka-telemetry-corrupt-'));
     try {
@@ -194,6 +210,42 @@ describe('FileTelemetryRepo', () => {
       await rm(root, { recursive: true, force: true, maxRetries: 5, retryDelay: 20 });
     }
   });
+
+  test('load rejects wrong telemetry schema without overwriting bytes', async () => {
+    const root = await mkdtemp(join(tmpdir(), 'maka-telemetry-wrong-schema-'));
+    try {
+      const wrongShape = JSON.stringify({ reminders: [] }, null, 2) + '\n';
+      await writeFile(join(root, 'telemetry.json'), wrongShape, 'utf8');
+      const repo = createTelemetryRepo(root);
+
+      await assert.rejects(
+        () => repo.load(),
+        /expected known telemetry sections/,
+      );
+      assert.equal(await readFile(join(root, 'telemetry.json'), 'utf8'), wrongShape);
+    } finally {
+      await flushWrites();
+      await rm(root, { recursive: true, force: true, maxRetries: 5, retryDelay: 20 });
+    }
+  });
+
+  test('load rejects known telemetry sections with non-array values', async () => {
+    const root = await mkdtemp(join(tmpdir(), 'maka-telemetry-bad-section-'));
+    try {
+      const wrongShape = JSON.stringify({ usageRecords: {} }, null, 2) + '\n';
+      await writeFile(join(root, 'telemetry.json'), wrongShape, 'utf8');
+      const repo = createTelemetryRepo(root);
+
+      await assert.rejects(
+        () => repo.load(),
+        /usageRecords must be an array/,
+      );
+      assert.equal(await readFile(join(root, 'telemetry.json'), 'utf8'), wrongShape);
+    } finally {
+      await flushWrites();
+      await rm(root, { recursive: true, force: true, maxRetries: 5, retryDelay: 20 });
+    }
+  });
 });
 
 async function withRepo(fn: (repo: ReturnType<typeof createTelemetryRepo>) => Promise<void>): Promise<void> {

packages/storage/src/telemetry-repo.ts

@@ -234,15 +234,33 @@ function emptyFile(): TelemetryFile {
 }
 
 function normalizeFile(input: unknown): TelemetryFile {
-  if (!input || typeof input !== 'object') return emptyFile();
+  if (!input || typeof input !== 'object' || Array.isArray(input)) {
+    throw new Error('Invalid telemetry file: expected an object');
+  }
   const value = input as Partial<TelemetryFile>;
+  const hasKnownSection =
+    'usageRecords' in value ||
+    'toolInvocations' in value ||
+    'pricingOverrides' in value;
+  if (!hasKnownSection) {
+    throw new Error('Invalid telemetry file: expected known telemetry sections');
+  }
+  assertOptionalArraySection(value, 'usageRecords');
+  assertOptionalArraySection(value, 'toolInvocations');
+  assertOptionalArraySection(value, 'pricingOverrides');
   return {
-    usageRecords: Array.isArray(value.usageRecords) ? value.usageRecords.map(normalizeLlmCallRecord) : [],
-    toolInvocations: Array.isArray(value.toolInvocations) ? value.toolInvocations : [],
-    pricingOverrides: Array.isArray(value.pricingOverrides) ? value.pricingOverrides : [],
+    usageRecords: value.usageRecords ? value.usageRecords.map(normalizeLlmCallRecord) : [],
+    toolInvocations: value.toolInvocations ?? [],
+    pricingOverrides: value.pricingOverrides ?? [],
   };
 }
 
+function assertOptionalArraySection<T extends object>(value: T, key: keyof T): void {
+  if (key in value && !Array.isArray(value[key])) {
+    throw new Error(`Invalid telemetry file: ${String(key)} must be an array`);
+  }
+}
+
 function normalizeLlmCallRecord(input: unknown): PersistedLlmCallRecord {
   const row = input as Partial<PersistedLlmCallRecord>;
   const inputTokens = finiteNumber(row.inputTokens) ?? 0;