fix: Fix null payload data in historyFromJSON (#1109)

* fix: Fix null payload data in historyFromJSON

* Address review comments + general improvement

Author: mjameswh

package-lock.json

@@ -22,12 +22,36 @@ function fixEnumValue<O extends Record<string, any>>(obj: O, attr: keyof O, pref
   );
 }
 
+// fromProto3JSON doesn't allow null values on 'bytes' fields. This turns out to be a problem for payloads.
+// Recursively descend on objects and array, and fix in-place any payload that has a null data field
+function fixPayloads<T>(e: T): T {
+  function isPayload(p: any): p is JSONPayload {
+    return p && typeof p === 'object' && 'metadata' in p && 'data' in p;
+  }
+
+  if (e && typeof e === 'object') {
+    if (isPayload(e)) {
+      if (e.data === null) {
+        const { data: _data, ...rest } = e;
+        return rest as T;
+      }
+      return e;
+    }
+    if (Array.isArray(e)) return e.map(fixPayloads) as T;
+    return Object.fromEntries(Object.entries(e as object).map(([k, v]) => [k, fixPayloads(v)])) as T;
+  }
+  return e;
+}
+
 function fixHistoryEvent(e: Record<string, any>) {
   const type = Object.keys(e).find((k) => k.endsWith('EventAttributes'));
   if (!type) {
     throw new TypeError(`Missing attributes in history event: ${JSON.stringify(e)}`);
   }
 
+  // Fix payloads with null data
+  e = fixPayloads(e);
+
   return {
     ...e,
     ...fixEnumValue(e, 'eventType', 'EVENT_TYPE'),

packages/common/src/proto-utils.ts

@@ -22,3 +22,35 @@ test('cancel-fake-progress-replay', async (t) => {
   );
   t.is(hist.events?.[0].workflowExecutionStartedEventAttributes?.taskQueue?.kind, TaskQueueKind.TASK_QUEUE_KIND_NORMAL);
 });
+
+test('null payload data doesnt crash', async (t) => {
+  const historyJson = {
+    events: [
+      {
+        eventId: '16',
+        eventTime: '2022-07-06T00:33:18.000Z',
+        eventType: 'WorkflowExecutionCompleted',
+        version: '0',
+        taskId: '1057236',
+        workflowExecutionCompletedEventAttributes: {
+          result: { payloads: [{ metadata: { encoding: 'YmluYXJ5L251bGw=' }, data: null }] },
+          workflowTaskCompletedEventId: '15',
+          newExecutionRunId: '',
+        },
+      },
+    ],
+  };
+
+  // This would throw an error if payload data was still null
+  const history = historyFromJSON(historyJson);
+
+  // Make sure that other history properties were not corrupted
+  t.is(
+    Buffer.from(
+      // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+      history.events?.[0].workflowExecutionCompletedEventAttributes?.result?.payloads?.[0].metadata!
+        .encoding as Uint8Array
+    ).toString(),
+    'binary/null'
+  );
+});