fix: Redact anonymous context attributes in migration op and custom events

packages/shared/common/__tests__/internal/events/EventProcessor.test.ts

@@ -468,6 +468,54 @@ describe('given an event processor', () => {
     ]);
   });
 
+  it('redacts all attributes from anonymous context for migration op events', async () => {
+    const userObj = { key: 'user-key', kind: 'user', name: 'Example user', anonymous: true };
+    const context = Context.fromLDContext(userObj);
+
+    Date.now = jest.fn(() => 1000);
+    eventProcessor.sendEvent({
+      kind: 'migration_op',
+      operation: 'read',
+      creationDate: 1000,
+      context,
+      evaluation: {
+        key: 'flagkey',
+        value: 'live',
+        default: 'off',
+        reason: { kind: 'FALLTHROUGH' },
+      },
+      measurements: [],
+      samplingRatio: 1,
+    });
+
+    await eventProcessor.flush();
+
+    const redactedContext = {
+      kind: 'user',
+      key: 'user-key',
+      anonymous: true,
+      _meta: {
+        redactedAttributes: ['name'],
+      },
+    };
+
+    expect(mockSendEventData).toBeCalledWith(LDEventType.AnalyticsEvents, [
+      {
+        kind: 'migration_op',
+        operation: 'read',
+        creationDate: 1000,
+        context: redactedContext,
+        evaluation: {
+          key: 'flagkey',
+          value: 'live',
+          default: 'off',
+          reason: { kind: 'FALLTHROUGH' },
+        },
+        measurements: [],
+      },
+    ]);
+  });
+
   it('expires debug mode based on client time if client time is later than server time', async () => {
     Date.now = jest.fn(() => 2000);
 
@@ -689,6 +737,15 @@ describe('given an event processor', () => {
 
     await eventProcessor.flush();
 
+    // The custom event inlines the context, so an anonymous context's attributes are redacted.
+    // The index event is not subject to anonymous redaction and keeps the full context.
+    const redactedAnonUser = {
+      key: 'anon-user',
+      kind: 'user',
+      anonymous: true,
+      _meta: { redactedAttributes: ['name'] },
+    };
+
     expect(mockSendEventData).toBeCalledWith(LDEventType.AnalyticsEvents, [
       {
         kind: 'index',
@@ -700,7 +757,7 @@ describe('given an event processor', () => {
         key: 'eventkey',
         data: { thing: 'stuff' },
         creationDate: 1000,
-        context: { ...anonUser, kind: 'user' },
+        context: redactedAnonUser,
       },
     ]);
   });

packages/shared/common/src/internal/events/EventProcessor.ts

@@ -263,7 +263,9 @@ export default class EventProcessor implements LDEventProcessor {
       if (shouldSample(inputEvent.samplingRatio)) {
         const migrationEvent: MigrationOutputEvent = {
           ...inputEvent,
-          context: inputEvent.context ? this._contextFilter.filter(inputEvent.context) : undefined,
+          context: inputEvent.context
+            ? this._contextFilter.filter(inputEvent.context, true)
+            : undefined,
         };
         if (migrationEvent.samplingRatio === 1) {
           delete migrationEvent.samplingRatio;
@@ -359,7 +361,7 @@ export default class EventProcessor implements LDEventProcessor {
           kind: 'custom',
           creationDate: event.creationDate,
           key: event.key,
-          context: this._contextFilter.filter(event.context),
+          context: this._contextFilter.filter(event.context, true),
         };
 
         if (event.samplingRatio !== 1) {