Transform all possible identity fields to formatted strings in wit_get_work_items_batch_by_ids (#410)

The function `get_work_items_batch_by_ids` transforms the field
`System.AssignedTo` to contain a simple `name <email>`. With pull
request #385 , users can choose returned fields. It would be great to
transform all possible identity fields:

- System.AssignedTo
- System.CreatedBy
- System.ChangedBy
- System.AuthorizedAs
- Microsoft.VSTS.Common.ActivatedBy
- Microsoft.VSTS.Common.ResolvedBy
- Microsoft.VSTS.Common.ClosedBy

The proposed implementation leverages a list of known identity fields.
An alternative would be to detect if the field looks like an identity.
The risk is that it might find false positives.

## GitHub issue number

#409 

## **Associated Risks**

_Replace_ by possible risks this pull request can bring you might have
thought of

## ✅ **PR Checklist**

- [x] **I have read the [contribution
guidelines](https://github.com/microsoft/azure-devops-mcp/blob/main/CONTRIBUTING.md)**
- [x] **I have read the [code of conduct
guidelines](https://github.com/microsoft/azure-devops-mcp/blob/main/CODE_OF_CONDUCT.md)**
- [x] Title of the pull request is clear and informative.
- [x] 👌 Code hygiene
- [x] 🔭 Telemetry added, updated, or N/A
- [x] 📄 Documentation added, updated, or N/A
- [x] 🛡️ Automated tests added, or N/A

## 🧪 **How did you test it?**

- Added new unit test

Co-authored-by: Francisco <[email protected]>
Co-authored-by: Dan Hellem <[email protected]>

Author: 3 people

src/tools/workitems.ts

@@ -142,15 +142,30 @@ function configureWorkItemTools(server: McpServer, tokenProvider: () => Promise<
 
       const workitems = await workItemApi.getWorkItemsBatch({ ids, fields: fieldsToUse }, project);
 
-      // Format the assignedTo field to include displayName and uniqueName
+      // List of identity fields that need to be transformed from objects to formatted strings
+      const identityFields = [
+        "System.AssignedTo",
+        "System.CreatedBy",
+        "System.ChangedBy",
+        "System.AuthorizedAs",
+        "Microsoft.VSTS.Common.ActivatedBy",
+        "Microsoft.VSTS.Common.ResolvedBy",
+        "Microsoft.VSTS.Common.ClosedBy",
+      ];
+
+      // Format identity fields to include displayName and uniqueName
       // Removing the identity object as the response. It's too much and not needed
       if (workitems && Array.isArray(workitems)) {
         workitems.forEach((item) => {
-          if (item.fields && item.fields["System.AssignedTo"] && typeof item.fields["System.AssignedTo"] === "object") {
-            const assignedTo = item.fields["System.AssignedTo"];
-            const name = assignedTo.displayName || "";
-            const email = assignedTo.uniqueName || "";
-            item.fields["System.AssignedTo"] = `${name} <${email}>`.trim();
+          if (item.fields) {
+            identityFields.forEach((fieldName) => {
+              if (item.fields && item.fields[fieldName] && typeof item.fields[fieldName] === "object") {
+                const identityField = item.fields[fieldName];
+                const name = identityField.displayName || "";
+                const email = identityField.uniqueName || "";
+                item.fields[fieldName] = `${name} <${email}>`.trim();
+              }
+            });
           }
         });
       }

test/src/tools/workitems.test.ts

@@ -571,6 +571,83 @@ describe("configureWorkItemTools", () => {
 
       expect(result.content[0].text).toBe(JSON.stringify(null, null, 2));
     });
+
+    it("should transform all user fields to formatted strings", async () => {
+      configureWorkItemTools(server, tokenProvider, connectionProvider, userAgentProvider);
+
+      const call = (server.tool as jest.Mock).mock.calls.find(([toolName]) => toolName === "wit_get_work_items_batch_by_ids");
+
+      if (!call) throw new Error("wit_get_work_items_batch_by_ids tool not registered");
+      const [, , , handler] = call;
+
+      // Mock work items with all user fields as objects
+      const mockWorkItemsWithUserFields = [
+        {
+          id: 297,
+          fields: {
+            "System.Id": 297,
+            "System.WorkItemType": "Bug",
+            "System.Title": "Test Bug",
+            "System.AssignedTo": {
+              displayName: "John Doe",
+              uniqueName: "[email protected]",
+              id: "12345",
+            },
+            "System.CreatedBy": {
+              displayName: "Jane Smith",
+              uniqueName: "[email protected]",
+              id: "67890",
+            },
+            "System.ChangedBy": {
+              displayName: "Bob Johnson",
+              uniqueName: "[email protected]",
+              id: "11111",
+            },
+            "System.AuthorizedAs": {
+              displayName: "Alice Brown",
+              uniqueName: "[email protected]",
+              id: "22222",
+            },
+            "Microsoft.VSTS.Common.ActivatedBy": {
+              displayName: "Charlie Wilson",
+              uniqueName: "[email protected]",
+              id: "33333",
+            },
+            "Microsoft.VSTS.Common.ResolvedBy": {
+              displayName: "Diana Clark",
+              uniqueName: "[email protected]",
+              id: "44444",
+            },
+            "Microsoft.VSTS.Common.ClosedBy": {
+              displayName: "Edward Davis",
+              uniqueName: "[email protected]",
+              id: "55555",
+            },
+          },
+        },
+      ];
+
+      (mockWorkItemTrackingApi.getWorkItemsBatch as jest.Mock).mockResolvedValue(mockWorkItemsWithUserFields);
+
+      const params = {
+        ids: [297],
+        project: "Contoso",
+      };
+
+      const result = await handler(params);
+
+      // Parse the returned JSON to verify transformation
+      const resultData = JSON.parse(result.content[0].text);
+
+      // Verify that all user fields are transformed to formatted strings
+      expect(resultData[0].fields["System.AssignedTo"]).toBe("John Doe <[email protected]>");
+      expect(resultData[0].fields["System.CreatedBy"]).toBe("Jane Smith <[email protected]>");
+      expect(resultData[0].fields["System.ChangedBy"]).toBe("Bob Johnson <[email protected]>");
+      expect(resultData[0].fields["System.AuthorizedAs"]).toBe("Alice Brown <[email protected]>");
+      expect(resultData[0].fields["Microsoft.VSTS.Common.ActivatedBy"]).toBe("Charlie Wilson <[email protected]>");
+      expect(resultData[0].fields["Microsoft.VSTS.Common.ResolvedBy"]).toBe("Diana Clark <[email protected]>");
+      expect(resultData[0].fields["Microsoft.VSTS.Common.ClosedBy"]).toBe("Edward Davis <[email protected]>");
+    });
   });
 
   describe("get_work_item tool", () => {