feat: add RPC request handling endpoint

package.json

@@ -25,6 +25,7 @@
   "devDependencies": {
     "@types/express": "^4.17.21",
     "@types/node": "^20.11.0",
+    "@types/uuid": "^11.0.0",
     "@typescript-eslint/eslint-plugin": "^6.15.0",
     "@typescript-eslint/parser": "^6.15.0",
     "eslint": "^8.56.0",
@@ -39,6 +40,7 @@
     "@modelcontextprotocol/sdk": "^1.8.0",
     "dotenv": "^16.4.7",
     "express": "^4.21.2",
-    "falkordb": "^6.2.07"
+    "falkordb": "^6.2.07",
+    "uuid": "^13.0.0"
   }
 }

src/controllers/mcp.controller.test.ts

@@ -1,6 +1,6 @@
 import { Request, Response } from 'express';
-import { mcpController } from './mcp.controller';
 import { falkorDBService } from '../services/falkordb.service';
+import { mcpController } from './mcp.controller';
 
 // Mock the falkorDBService
 jest.mock('../services/falkordb.service', () => ({
@@ -10,6 +10,11 @@ jest.mock('../services/falkordb.service', () => ({
   }
 }));
 
+// Mock uuid
+jest.mock('uuid', () => ({
+  v4: jest.fn(() => 'test-uuid')
+}));
+
 describe('MCP Controller', () => {
   let mockRequest: Partial<Request>;
   let mockResponse: Partial<Response>;
@@ -25,7 +30,8 @@ describe('MCP Controller', () => {
     mockStatus = jest.fn().mockReturnThis();
     mockResponse = {
       json: mockJson,
-      status: mockStatus
+      status: mockStatus,
+      header: jest.fn().mockReturnThis()
     };
   });
 
@@ -129,4 +135,217 @@ describe('MCP Controller', () => {
       }));
     });
   });
+
+  describe('initialize', () => {
+    test('should return 400 if jsonrpc version is invalid', async () => {
+      mockRequest = {
+        body: {
+          jsonrpc: '1.0',
+          id: 1,
+          method: 'initialize'
+        }
+      };
+
+      await mcpController.initialize(mockRequest as Request, mockResponse as Response);
+
+      expect(mockStatus).toHaveBeenCalledWith(400);
+      expect(mockJson).toHaveBeenCalledWith(expect.objectContaining({
+        error: expect.objectContaining({
+          code: -32600
+        })
+      }));
+    });
+
+    test('should initialize session successfully', async () => {
+      mockRequest = {
+        body: {
+          jsonrpc: '2.0',
+          id: 1,
+          method: 'initialize'
+        }
+      };
+
+      await mcpController.initialize(mockRequest as Request, mockResponse as Response);
+
+      expect(mockResponse.header).toHaveBeenCalledWith('Mcp-Session-Id', expect.any(String));
+      expect(mockStatus).toHaveBeenCalledWith(200);
+      expect(mockJson).toHaveBeenCalledWith(expect.objectContaining({
+        result: expect.objectContaining({
+          serverInfo: expect.objectContaining({
+            name: 'FalkorDB MCP Server'
+          })
+        })
+      }));
+    });
+  });
+
+  describe('processMetadataRequest', () => {
+    test('should return metadata', async () => {
+      await mcpController.processMetadataRequest(mockRequest as Request, mockResponse as Response);
+
+      expect(mockStatus).toHaveBeenCalledWith(200);
+      expect(mockJson).toHaveBeenCalledWith(expect.objectContaining({
+        provider: 'FalkorDB MCP Server',
+        capabilities: expect.any(Array)
+      }));
+    });
+  });
+
+  describe('handleRpcRequest', () => {
+    test('should delegate initialize', async () => {
+      mockRequest = { body: { method: 'initialize', jsonrpc: '2.0', id: 1 } };
+      const spy = jest.spyOn(mcpController, 'initialize');
+      await mcpController.handleRpcRequest(mockRequest as Request, mockResponse as Response);
+      expect(spy).toHaveBeenCalled();
+    });
+
+    test('should handle notifications/initialized', async () => {
+      mockRequest = { body: { method: 'notifications/initialized', jsonrpc: '2.0' } };
+      await mcpController.handleRpcRequest(mockRequest as Request, mockResponse as Response);
+      expect(mockStatus).toHaveBeenCalledWith(200);
+      expect(mockJson).toHaveBeenCalledWith(expect.objectContaining({ result: true }));
+    });
+
+    test('should handle ping', async () => {
+      mockRequest = { body: { method: 'ping', jsonrpc: '2.0', id: 1 } };
+      await mcpController.handleRpcRequest(mockRequest as Request, mockResponse as Response);
+      expect(mockStatus).toHaveBeenCalledWith(200);
+      expect(mockJson).toHaveBeenCalledWith(expect.objectContaining({ result: {} }));
+    });
+
+    test('should handle tools/list', async () => {
+      mockRequest = { body: { method: 'tools/list', jsonrpc: '2.0', id: 1 } };
+      await mcpController.handleRpcRequest(mockRequest as Request, mockResponse as Response);
+      expect(mockStatus).toHaveBeenCalledWith(200);
+      expect(mockJson).toHaveBeenCalledWith(expect.objectContaining({
+        result: expect.objectContaining({ tools: expect.any(Array) })
+      }));
+    });
+
+    test('should handle resources/list', async () => {
+      mockRequest = { body: { method: 'resources/list', jsonrpc: '2.0', id: 1 } };
+      await mcpController.handleRpcRequest(mockRequest as Request, mockResponse as Response);
+      expect(mockStatus).toHaveBeenCalledWith(200);
+    });
+
+    test('should handle prompts/list', async () => {
+      mockRequest = { body: { method: 'prompts/list', jsonrpc: '2.0', id: 1 } };
+      await mcpController.handleRpcRequest(mockRequest as Request, mockResponse as Response);
+      expect(mockStatus).toHaveBeenCalledWith(200);
+    });
+
+    test('should return error for unknown method', async () => {
+      mockRequest = { body: { method: 'unknown', jsonrpc: '2.0', id: 1 } };
+      await mcpController.handleRpcRequest(mockRequest as Request, mockResponse as Response);
+      expect(mockStatus).toHaveBeenCalledWith(200); // It returns 200 with error body
+      expect(mockJson).toHaveBeenCalledWith(expect.objectContaining({
+        error: expect.objectContaining({ code: -32601 })
+      }));
+    });
+
+    describe('tools/call', () => {
+      test('should return error if tool not found', async () => {
+        mockRequest = {
+          body: {
+            method: 'tools/call',
+            jsonrpc: '2.0',
+            id: 1,
+            params: { name: 'unknown_tool', arguments: {} }
+          }
+        };
+        await mcpController.handleRpcRequest(mockRequest as Request, mockResponse as Response);
+        expect(mockJson).toHaveBeenCalledWith(expect.objectContaining({
+          error: expect.objectContaining({ code: -32601 })
+        }));
+      });
+
+      test('graph_query success', async () => {
+        (falkorDBService.executeQuery as jest.Mock).mockResolvedValue([{ id: 1 }]);
+        mockRequest = {
+          body: {
+            method: 'tools/call',
+            jsonrpc: '2.0',
+            id: 1,
+            params: { name: 'graph_query', arguments: { graphName: 'g', query: 'match n return n' } }
+          }
+        };
+        await mcpController.handleRpcRequest(mockRequest as Request, mockResponse as Response);
+        expect(falkorDBService.executeQuery).toHaveBeenCalledWith('g', 'match n return n', {});
+        expect(mockJson).toHaveBeenCalledWith(expect.objectContaining({
+          result: expect.objectContaining({ content: expect.any(Array) })
+        }));
+      });
+
+      test('list_graphs success', async () => {
+        (falkorDBService.listGraphs as jest.Mock).mockResolvedValue(['g1']);
+        mockRequest = {
+          body: {
+            method: 'tools/call',
+            jsonrpc: '2.0',
+            id: 1,
+            params: { name: 'list_graphs', arguments: {} }
+          }
+        };
+        await mcpController.handleRpcRequest(mockRequest as Request, mockResponse as Response);
+        expect(falkorDBService.listGraphs).toHaveBeenCalled();
+        expect(mockJson).toHaveBeenCalledWith(expect.objectContaining({
+          result: expect.objectContaining({ content: expect.any(Array) })
+        }));
+      });
+
+      test('get_graph_schema success', async () => {
+        (falkorDBService.executeQuery as jest.Mock).mockImplementation((graph, query) => {
+          if (query.includes('labels')) return Promise.resolve([{ label: 'Person' }]);
+          if (query.includes('relationshipTypes')) return Promise.resolve([{ relationshipType: 'KNOWS' }]);
+          if (query.includes('MATCH')) return Promise.resolve([]);
+          return Promise.resolve([]);
+        });
+
+        mockRequest = {
+          body: {
+            method: 'tools/call',
+            jsonrpc: '2.0',
+            id: 1,
+            params: { name: 'get_graph_schema', arguments: { graphName: 'g' } }
+          }
+        };
+        await mcpController.handleRpcRequest(mockRequest as Request, mockResponse as Response);
+        expect(mockJson).toHaveBeenCalledWith(expect.objectContaining({
+          result: expect.objectContaining({ content: expect.any(Array) })
+        }));
+      });
+
+      test('get_node_properties success', async () => {
+        (falkorDBService.executeQuery as jest.Mock).mockResolvedValue([{ props: {} }]);
+        mockRequest = {
+          body: {
+            method: 'tools/call',
+            jsonrpc: '2.0',
+            id: 1,
+            params: { name: 'get_node_properties', arguments: { graphName: 'g', label: 'L' } }
+          }
+        };
+        await mcpController.handleRpcRequest(mockRequest as Request, mockResponse as Response);
+        expect(mockJson).toHaveBeenCalledWith(expect.objectContaining({
+          result: expect.objectContaining({ content: expect.any(Array) })
+        }));
+      });
+
+      test('get_relationship_properties success', async () => {
+        (falkorDBService.executeQuery as jest.Mock).mockResolvedValue([{ props: {} }]);
+        mockRequest = {
+          body: {
+            method: 'tools/call',
+            jsonrpc: '2.0',
+            id: 1,
+            params: { name: 'get_relationship_properties', arguments: { graphName: 'g', relationshipType: 'R' } }
+          }
+        };
+        await mcpController.handleRpcRequest(mockRequest as Request, mockResponse as Response);
+        expect(mockJson).toHaveBeenCalledWith(expect.objectContaining({
+          result: expect.objectContaining({ content: expect.any(Array) })
+        }));
+      });
+    });
+  });
 });