Add MCP Roots support (#5856)

Co-authored-by: Jacob Richman <[email protected]>

1 files changed, 56 insertions, 1 deletions

diff --git a/packages/core/src/tools/mcp-client.test.ts b/packages/core/src/tools/mcp-client.test.ts
index 1ccba76a..d37c6eae 100644
--- a/packages/core/src/tools/mcp-client.test.ts
+++ b/packages/core/src/tools/mcp-client.test.ts
@@ -13,6 +13,7 @@ import {
   discoverTools,
   discoverPrompts,
   hasValidTypes,
+  connectToMcpServer,
 } from './mcp-client.js';
 import { SSEClientTransport } from '@modelcontextprotocol/sdk/client/sse.js';
 import * as SdkClientStdioLib from '@modelcontextprotocol/sdk/client/stdio.js';
@@ -23,6 +24,8 @@ import { AuthProviderType } from '../config/config.js';
 import { PromptRegistry } from '../prompts/prompt-registry.js';
 
 import { DiscoveredMCPTool } from './mcp-tool.js';
+import { WorkspaceContext } from '../utils/workspaceContext.js';
+import { pathToFileURL } from 'node:url';
 
 vi.mock('@modelcontextprotocol/sdk/client/stdio.js');
 vi.mock('@modelcontextprotocol/sdk/client/index.js');
@@ -276,6 +279,56 @@ describe('mcp-client', () => {
     });
   });
 
+  describe('connectToMcpServer', () => {
+    it('should register a roots/list handler', async () => {
+      const mockedClient = {
+        registerCapabilities: vi.fn(),
+        setRequestHandler: vi.fn(),
+        callTool: vi.fn(),
+        connect: vi.fn(),
+      };
+      vi.mocked(ClientLib.Client).mockReturnValue(
+        mockedClient as unknown as ClientLib.Client,
+      );
+      vi.spyOn(SdkClientStdioLib, 'StdioClientTransport').mockReturnValue(
+        {} as SdkClientStdioLib.StdioClientTransport,
+      );
+      const mockWorkspaceContext = {
+        getDirectories: vi
+          .fn()
+          .mockReturnValue(['/test/dir', '/another/project']),
+      } as unknown as WorkspaceContext;
+
+      await connectToMcpServer(
+        'test-server',
+        {
+          command: 'test-command',
+        },
+        false,
+        mockWorkspaceContext,
+      );
+
+      expect(mockedClient.registerCapabilities).toHaveBeenCalledWith({
+        roots: {},
+      });
+      expect(mockedClient.setRequestHandler).toHaveBeenCalledOnce();
+      const handler = mockedClient.setRequestHandler.mock.calls[0][1];
+      const roots = await handler();
+      expect(roots).toEqual({
+        roots: [
+          {
+            uri: pathToFileURL('/test/dir').toString(),
+            name: 'dir',
+          },
+          {
+            uri: pathToFileURL('/another/project').toString(),
+            name: 'project',
+          },
+        ],
+      });
+    });
+  });
+
   describe('discoverPrompts', () => {
     const mockedPromptRegistry = {
       registerPrompt: vi.fn(),
@@ -486,7 +539,9 @@ describe('mcp-client', () => {
     });
 
     it('should connect via command', async () => {
-      const mockedTransport = vi.mocked(SdkClientStdioLib.StdioClientTransport);
+      const mockedTransport = vi
+        .spyOn(SdkClientStdioLib, 'StdioClientTransport')
+        .mockReturnValue({} as SdkClientStdioLib.StdioClientTransport);
 
       await createTransport(
         'test-server',