add wikis tests to improve code coverage (#244)

Improve Wikis code coverage from;

```sh
----------------|---------|----------|---------|---------|------------------------------------------------------
File            | % Stmts | % Branch | % Funcs | % Lines | Uncovered Line #s                                    
----------------|---------|----------|---------|---------|------------------------------------------------------
      wikis.ts  |     100 |    70.58 |     100 |     100 | 39,69-89,110,145
----------------|---------|----------|---------|---------|------------------------------------------------------
```

to

```sh
----------------|---------|----------|---------|---------|------------------------------------------------------
File            | % Stmts | % Branch | % Funcs | % Lines | Uncovered Line #s                                    
----------------|---------|----------|---------|---------|------------------------------------------------------
      wikis.ts  |     100 |      100 |     100 |     100 |
----------------|---------|----------|---------|---------|------------------------------------------------------
```

## GitHub issue number

#57 (Don't close the issue, there are other tools to improve test
coverages)

## **Associated Risks**

None

## ✅ **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?**

Run `npm run test` in the project root

Author: polatengin

test/src/tools/wiki.test.ts

@@ -104,6 +104,26 @@ describe("configureWikiTools", () => {
       expect(result.isError).toBe(true);
       expect(result.content[0].text).toBe("No wiki found");
     });
+
+    it("should handle unknown error type correctly", async () => {
+      configureWikiTools(server, tokenProvider, connectionProvider);
+      const call = (server.tool as jest.Mock).mock.calls.find(([toolName]) => toolName === "wiki_get_wiki");
+      if (!call) throw new Error("wiki_get_wiki tool not registered");
+      const [, , , handler] = call;
+
+      mockWikiApi.getWiki.mockRejectedValue("string error");
+
+      const params = {
+        wikiIdentifier: "wiki1",
+        project: "proj1",
+      };
+
+      const result = await handler(params);
+
+      expect(mockWikiApi.getWiki).toHaveBeenCalled();
+      expect(result.isError).toBe(true);
+      expect(result.content[0].text).toContain("Error fetching wiki: Unknown error occurred");
+    });
   });
 
   describe("list_wikis tool", () => {
@@ -168,6 +188,25 @@ describe("configureWikiTools", () => {
       expect(result.isError).toBe(true);
       expect(result.content[0].text).toBe("No wikis found");
     });
+
+    it("should handle unknown error type correctly", async () => {
+      configureWikiTools(server, tokenProvider, connectionProvider);
+      const call = (server.tool as jest.Mock).mock.calls.find(([toolName]) => toolName === "wiki_list_wikis");
+      if (!call) throw new Error("wiki_list_wikis tool not registered");
+      const [, , , handler] = call;
+
+      mockWikiApi.getAllWikis.mockRejectedValue("string error");
+
+      const params = {
+        project: "proj1",
+      };
+
+      const result = await handler(params);
+
+      expect(mockWikiApi.getAllWikis).toHaveBeenCalled();
+      expect(result.isError).toBe(true);
+      expect(result.content[0].text).toContain("Error fetching wikis: Unknown error occurred");
+    });
   });
 
   describe("list_wiki_pages tool", () => {
@@ -201,6 +240,31 @@ describe("configureWikiTools", () => {
       expect(result.isError).toBeUndefined();
     });
 
+    it("should use default top parameter when not provided", async () => {
+      configureWikiTools(server, tokenProvider, connectionProvider);
+      const call = (server.tool as jest.Mock).mock.calls.find(([toolName]) => toolName === "wiki_list_pages");
+      if (!call) throw new Error("wiki_list_pages tool not registered");
+      const [, , , handler] = call;
+      mockWikiApi.getPagesBatch.mockResolvedValue({ value: ["page1", "page2"] });
+
+      const params = {
+        wikiIdentifier: "wiki1",
+        project: "proj1",
+      };
+      const result = await handler(params);
+
+      expect(mockWikiApi.getPagesBatch).toHaveBeenCalledWith(
+        {
+          top: 20,
+          continuationToken: undefined,
+          pageViewsForDays: undefined,
+        },
+        "proj1",
+        "wiki1"
+      );
+      expect(result.isError).toBeUndefined();
+    });
+
     it("should handle API errors correctly", async () => {
       configureWikiTools(server, tokenProvider, connectionProvider);
       const call = (server.tool as jest.Mock).mock.calls.find(([toolName]) => toolName === "wiki_list_pages");
@@ -243,6 +307,27 @@ describe("configureWikiTools", () => {
       expect(result.isError).toBe(true);
       expect(result.content[0].text).toBe("No wiki pages found");
     });
+
+    it("should handle unknown error type correctly", async () => {
+      configureWikiTools(server, tokenProvider, connectionProvider);
+      const call = (server.tool as jest.Mock).mock.calls.find(([toolName]) => toolName === "wiki_list_pages");
+      if (!call) throw new Error("wiki_list_pages tool not registered");
+      const [, , , handler] = call;
+
+      mockWikiApi.getPagesBatch.mockRejectedValue("string error");
+
+      const params = {
+        wikiIdentifier: "wiki1",
+        project: "proj1",
+        top: 10,
+      };
+
+      const result = await handler(params);
+
+      expect(mockWikiApi.getPagesBatch).toHaveBeenCalled();
+      expect(result.isError).toBe(true);
+      expect(result.content[0].text).toContain("Error fetching wiki pages: Unknown error occurred");
+    });
   });
 
   describe("get_page_content tool", () => {
@@ -353,5 +438,26 @@ describe("configureWikiTools", () => {
       expect(result.isError).toBe(true);
       expect(result.content[0].text).toContain("Error fetching wiki page content: Stream read error");
     });
+
+    it("should handle unknown error type correctly", async () => {
+      configureWikiTools(server, tokenProvider, connectionProvider);
+      const call = (server.tool as jest.Mock).mock.calls.find(([toolName]) => toolName === "wiki_get_page_content");
+      if (!call) throw new Error("wiki_get_page_content tool not registered");
+      const [, , , handler] = call;
+
+      mockWikiApi.getPageText.mockRejectedValue("string error");
+
+      const params = {
+        wikiIdentifier: "wiki1",
+        project: "proj1",
+        path: "/page1",
+      };
+
+      const result = await handler(params);
+
+      expect(mockWikiApi.getPageText).toHaveBeenCalled();
+      expect(result.isError).toBe(true);
+      expect(result.content[0].text).toContain("Error fetching wiki page content: Unknown error occurred");
+    });
   });
 });