fix: wrap child group transformer in try/catch to keep burst resilient

A throwing custom groupTransformer on a child group member would fail
the entire groups-phase burst. Apply the same try/catch + debug/warn
logging pattern already used for user member transformation.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Signed-off-by: pillaris <pillaris@adobe.com>

plugins/catalog-backend-module-msgraph-incremental/src/MicrosoftGraphIncrementalEntityProvider.test.ts

@@ -728,6 +728,70 @@ describe('MicrosoftGraphIncrementalEntityProvider', () => {
       expect(parentEntity!.entity.spec?.children).toHaveLength(0);
     });
 
+    it('logs a warning and skips a child group member when the transformer throws', async () => {
+      const throwingGroupTransformer = jest
+        .fn()
+        .mockResolvedValueOnce({
+          // first call: parent group transform succeeds
+          apiVersion: 'backstage.io/v1alpha1',
+          kind: 'Group',
+          metadata: {
+            name: 'parent-group',
+            annotations: { 'graph.microsoft.com/group-id': 'grp-parent' },
+          },
+          spec: { type: 'team', children: [], members: [] },
+        })
+        .mockRejectedValueOnce(new Error('Transformer error'));
+
+      (mockClient.getOrganization as jest.Mock).mockResolvedValue({
+        id: 'org-id',
+        displayName: 'My Org',
+      });
+      mockRequestOnePage.mockResolvedValueOnce({
+        items: [
+          {
+            id: 'grp-parent',
+            displayName: 'Parent',
+            mail: 'parent@example.com',
+          },
+        ],
+        nextLink: undefined,
+      });
+      (mockClient.getGroupMembers as jest.Mock).mockReturnValue(
+        asyncYield({
+          '@odata.type': '#microsoft.graph.group',
+          id: 'grp-child',
+          displayName: 'Child Group',
+          mail: 'child@example.com',
+        }),
+      );
+
+      const provider = new MicrosoftGraphIncrementalEntityProvider({
+        id: 'default',
+        provider: baseProviderConfig as any,
+        logger,
+        groupTransformer: throwingGroupTransformer,
+      });
+
+      const result = await provider.next(makeContext(), groupsCursor);
+
+      // Parent group still emitted despite child transformer throwing
+      const parentEntity = result.entities!.find(
+        e =>
+          e.entity.metadata.annotations?.[
+            MICROSOFT_GRAPH_GROUP_ID_ANNOTATION
+          ] === 'grp-parent',
+      );
+      expect(parentEntity).toBeDefined();
+      expect(parentEntity!.entity.spec?.children).toHaveLength(0);
+      expect(logger.warn).toHaveBeenCalledWith(
+        expect.stringContaining(
+          'group member child group grp-child failed to transform, skipping',
+        ),
+        expect.anything(),
+      );
+    });
+
     it('returns done:false with groups cursor when nextLink is present', async () => {
       const nextLink =
         'https://graph.microsoft.com/v1.0/groups?$skiptoken=page2';

plugins/catalog-backend-module-msgraph-incremental/src/MicrosoftGraphIncrementalEntityProvider.ts

@@ -481,14 +481,29 @@ export class MicrosoftGraphIncrementalEntityProvider
               // With a filter, child groups may not be ingested themselves,
               // which would produce dangling spec.children references.
               if (!provider.groupFilter && !provider.groupSearch) {
-                const childEntity = await groupTransformer(
-                  member as MicrosoftGraph.Group,
-                );
-                if (childEntity) {
-                  childEntity.metadata.name = capEntityName(
-                    childEntity.metadata.name,
+                try {
+                  const childEntity = await groupTransformer(
+                    member as MicrosoftGraph.Group,
+                  );
+                  if (childEntity) {
+                    childEntity.metadata.name = capEntityName(
+                      childEntity.metadata.name,
+                    );
+                    childRefs.push(stringifyEntityRef(childEntity));
+                  } else {
+                    this.options.logger.debug(
+                      `${this.getProviderName()}: group member child group ${
+                        member.id
+                      } could not be transformed (sparse object?), skipping`,
+                    );
+                  }
+                } catch (e) {
+                  this.options.logger.warn(
+                    `${this.getProviderName()}: group member child group ${
+                      member.id
+                    } failed to transform, skipping`,
+                    { error: e },
                   );
-                  childRefs.push(stringifyEntityRef(childEntity));
                 }
               }
             }