chore: upgrade Node.js to v22 for development and expand test coverage

.github/workflows/lint.yml

@@ -17,7 +17,7 @@ jobs:
       - name: Set up Node.js
         uses: actions/setup-node@v4
         with:
-          node-version: '18'
+          node-version: '22'
           cache: 'npm'
 
       - name: Install dependencies

.github/workflows/test.yml

@@ -13,7 +13,7 @@ jobs:
 
     strategy:
       matrix:
-        node-version: [18, 20]
+        node-version: [18, 20, 22, 23]
 
     steps:
       - uses: actions/checkout@v4

.nvmrc

@@ -1 +1 @@
-v18
+v22

README.md

@@ -24,6 +24,10 @@ This demo showcases how to build sophisticated AI agents using MCP over MQTT for
 - 🔍 **Auto Discovery**: Automatic server discovery over MQTT topics
 - 🌍 **Environment Detection**: Automatic browser/Node.js detection with appropriate defaults
 
+## Requirements
+
+- Node.js >= 18
+
 ## Installation
 
 ```bash

src/shared/utils.ts

@@ -36,18 +36,20 @@ export function createNotification(method: string, params?: Record<string, any>)
 }
 
 export function isRequest(message: any): message is JSONRPCRequest {
-  return message && typeof message === 'object' && message.jsonrpc === '2.0' && 'method' in message && 'id' in message
+  return Boolean(
+    message && typeof message === 'object' && message.jsonrpc === '2.0' && 'method' in message && 'id' in message,
+  )
 }
 
 export function isResponse(message: any): message is JSONRPCResponse {
-  return (
-    message && typeof message === 'object' && message.jsonrpc === '2.0' && 'id' in message && !('method' in message)
+  return Boolean(
+    message && typeof message === 'object' && message.jsonrpc === '2.0' && 'id' in message && !('method' in message),
   )
 }
 
 export function isNotification(message: any): message is JSONRPCNotification {
-  return (
-    message && typeof message === 'object' && message.jsonrpc === '2.0' && 'method' in message && !('id' in message)
+  return Boolean(
+    message && typeof message === 'object' && message.jsonrpc === '2.0' && 'method' in message && !('id' in message),
   )
 }
 

test/types.test.ts

@@ -0,0 +1,193 @@
+import { describe, it, expect } from '@jest/globals'
+import {
+  JSONRPCRequestSchema,
+  JSONRPCResponseSchema,
+  JSONRPCNotificationSchema,
+  ToolSchema,
+  ResourceSchema,
+  ErrorCode,
+} from '../src/types.js'
+
+describe('Types and Schemas', () => {
+  describe('JSONRPCRequestSchema', () => {
+    it('should validate a valid request', () => {
+      const request = {
+        jsonrpc: '2.0',
+        id: 'test-123',
+        method: 'tools/call',
+        params: { name: 'test-tool' },
+      }
+      const result = JSONRPCRequestSchema.safeParse(request)
+      expect(result.success).toBe(true)
+    })
+
+    it('should validate request with numeric id', () => {
+      const request = {
+        jsonrpc: '2.0',
+        id: 123,
+        method: 'test',
+      }
+      const result = JSONRPCRequestSchema.safeParse(request)
+      expect(result.success).toBe(true)
+    })
+
+    it('should reject invalid jsonrpc version', () => {
+      const request = {
+        jsonrpc: '1.0',
+        id: 'test',
+        method: 'test',
+      }
+      const result = JSONRPCRequestSchema.safeParse(request)
+      expect(result.success).toBe(false)
+    })
+
+    it('should reject request without method', () => {
+      const request = {
+        jsonrpc: '2.0',
+        id: 'test',
+      }
+      const result = JSONRPCRequestSchema.safeParse(request)
+      expect(result.success).toBe(false)
+    })
+  })
+
+  describe('JSONRPCResponseSchema', () => {
+    it('should validate a successful response', () => {
+      const response = {
+        jsonrpc: '2.0',
+        id: 'test-123',
+        result: { data: 'success' },
+      }
+      const result = JSONRPCResponseSchema.safeParse(response)
+      expect(result.success).toBe(true)
+    })
+
+    it('should validate an error response', () => {
+      const response = {
+        jsonrpc: '2.0',
+        id: 'test-123',
+        error: {
+          code: ErrorCode.INVALID_PARAMS,
+          message: 'Invalid parameters',
+        },
+      }
+      const result = JSONRPCResponseSchema.safeParse(response)
+      expect(result.success).toBe(true)
+    })
+
+    it('should validate error response with data', () => {
+      const response = {
+        jsonrpc: '2.0',
+        id: 'test-123',
+        error: {
+          code: ErrorCode.INTERNAL_ERROR,
+          message: 'Internal error',
+          data: { details: 'More info' },
+        },
+      }
+      const result = JSONRPCResponseSchema.safeParse(response)
+      expect(result.success).toBe(true)
+    })
+  })
+
+  describe('JSONRPCNotificationSchema', () => {
+    it('should validate a valid notification', () => {
+      const notification = {
+        jsonrpc: '2.0',
+        method: 'notifications/server/online',
+        params: { server_name: 'test' },
+      }
+      const result = JSONRPCNotificationSchema.safeParse(notification)
+      expect(result.success).toBe(true)
+    })
+
+    it('should validate notification without params', () => {
+      const notification = {
+        jsonrpc: '2.0',
+        method: 'notifications/disconnected',
+      }
+      const result = JSONRPCNotificationSchema.safeParse(notification)
+      expect(result.success).toBe(true)
+    })
+  })
+
+  describe('ToolSchema', () => {
+    it('should validate a valid tool', () => {
+      const tool = {
+        name: 'test-tool',
+        description: 'A test tool',
+        inputSchema: {
+          type: 'object',
+          properties: {
+            input: { type: 'string' },
+          },
+        },
+      }
+      const result = ToolSchema.safeParse(tool)
+      expect(result.success).toBe(true)
+    })
+
+    it('should validate tool without description', () => {
+      const tool = {
+        name: 'minimal-tool',
+        inputSchema: {},
+      }
+      const result = ToolSchema.safeParse(tool)
+      expect(result.success).toBe(true)
+    })
+
+    it('should reject tool without name', () => {
+      const tool = {
+        inputSchema: {},
+      }
+      const result = ToolSchema.safeParse(tool)
+      expect(result.success).toBe(false)
+    })
+  })
+
+  describe('ResourceSchema', () => {
+    it('should validate a valid resource', () => {
+      const resource = {
+        uri: 'file:///path/to/resource',
+        name: 'Test Resource',
+        description: 'A test resource',
+        mimeType: 'text/plain',
+      }
+      const result = ResourceSchema.safeParse(resource)
+      expect(result.success).toBe(true)
+    })
+
+    it('should validate resource with minimal fields', () => {
+      const resource = {
+        uri: 'file:///path',
+        name: 'Minimal',
+      }
+      const result = ResourceSchema.safeParse(resource)
+      expect(result.success).toBe(true)
+    })
+
+    it('should reject resource without uri', () => {
+      const resource = {
+        name: 'No URI',
+      }
+      const result = ResourceSchema.safeParse(resource)
+      expect(result.success).toBe(false)
+    })
+  })
+
+  describe('ErrorCode', () => {
+    it('should have correct JSON-RPC error codes', () => {
+      expect(ErrorCode.PARSE_ERROR).toBe(-32700)
+      expect(ErrorCode.INVALID_REQUEST).toBe(-32600)
+      expect(ErrorCode.METHOD_NOT_FOUND).toBe(-32601)
+      expect(ErrorCode.INVALID_PARAMS).toBe(-32602)
+      expect(ErrorCode.INTERNAL_ERROR).toBe(-32603)
+    })
+
+    it('should have correct MCP-specific error codes', () => {
+      expect(ErrorCode.INVALID_MESSAGE).toBe(-32000)
+      expect(ErrorCode.TOOL_NOT_FOUND).toBe(-32001)
+      expect(ErrorCode.RESOURCE_NOT_FOUND).toBe(-32002)
+    })
+  })
+})

test/utils.test.ts

@@ -5,7 +5,18 @@ jest.mock('nanoid', () => ({
   nanoid: jest.fn(() => 'mock-id-123'),
 }))
 
-import { createRequest, createResponse, createNotification, generateId, McpError } from '../src/shared/utils.js'
+import {
+  createRequest,
+  createResponse,
+  createNotification,
+  generateId,
+  McpError,
+  isRequest,
+  isResponse,
+  isNotification,
+  isNode,
+  isBrowser,
+} from '../src/shared/utils.js'
 import { ErrorCode } from '../src/types.js'
 
 describe('Utils', () => {
@@ -94,5 +105,117 @@ describe('Utils', () => {
         throw new McpError(ErrorCode.INTERNAL_ERROR, 'Something went wrong')
       }).toThrow(McpError)
     })
+
+    it('should serialize to JSON correctly', () => {
+      const error = new McpError(ErrorCode.INVALID_PARAMS, 'Invalid parameters', { field: 'name' })
+      const json = error.toJSON()
+
+      expect(json).toEqual({
+        code: ErrorCode.INVALID_PARAMS,
+        message: 'Invalid parameters',
+        data: { field: 'name' },
+      })
+    })
+
+    it('should serialize to JSON without data when not provided', () => {
+      const error = new McpError(ErrorCode.INTERNAL_ERROR, 'Internal error')
+      const json = error.toJSON()
+
+      expect(json).toEqual({
+        code: ErrorCode.INTERNAL_ERROR,
+        message: 'Internal error',
+      })
+      expect('data' in json).toBe(false)
+    })
+  })
+
+  describe('isRequest', () => {
+    it('should return true for valid request', () => {
+      const request = { jsonrpc: '2.0', id: '123', method: 'test' }
+      expect(isRequest(request)).toBe(true)
+    })
+
+    it('should return false for response', () => {
+      const response = { jsonrpc: '2.0', id: '123', result: {} }
+      expect(isRequest(response)).toBe(false)
+    })
+
+    it('should return false for notification', () => {
+      const notification = { jsonrpc: '2.0', method: 'test' }
+      expect(isRequest(notification)).toBe(false)
+    })
+
+    it('should return false for invalid objects', () => {
+      expect(isRequest(null)).toBe(false)
+      expect(isRequest(undefined)).toBe(false)
+      expect(isRequest({})).toBe(false)
+      expect(isRequest({ jsonrpc: '1.0', id: '1', method: 'test' })).toBe(false)
+    })
+  })
+
+  describe('isResponse', () => {
+    it('should return true for valid response with result', () => {
+      const response = { jsonrpc: '2.0', id: '123', result: { data: 'test' } }
+      expect(isResponse(response)).toBe(true)
+    })
+
+    it('should return true for valid response with error', () => {
+      const response = { jsonrpc: '2.0', id: '123', error: { code: -32600, message: 'Invalid' } }
+      expect(isResponse(response)).toBe(true)
+    })
+
+    it('should return false for request', () => {
+      const request = { jsonrpc: '2.0', id: '123', method: 'test' }
+      expect(isResponse(request)).toBe(false)
+    })
+
+    it('should return false for notification', () => {
+      const notification = { jsonrpc: '2.0', method: 'test' }
+      expect(isResponse(notification)).toBe(false)
+    })
+
+    it('should return false for invalid objects', () => {
+      expect(isResponse(null)).toBe(false)
+      expect(isResponse(undefined)).toBe(false)
+      expect(isResponse({})).toBe(false)
+    })
+  })
+
+  describe('isNotification', () => {
+    it('should return true for valid notification', () => {
+      const notification = { jsonrpc: '2.0', method: 'test' }
+      expect(isNotification(notification)).toBe(true)
+    })
+
+    it('should return true for notification with params', () => {
+      const notification = { jsonrpc: '2.0', method: 'test', params: { key: 'value' } }
+      expect(isNotification(notification)).toBe(true)
+    })
+
+    it('should return false for request', () => {
+      const request = { jsonrpc: '2.0', id: '123', method: 'test' }
+      expect(isNotification(request)).toBe(false)
+    })
+
+    it('should return false for response', () => {
+      const response = { jsonrpc: '2.0', id: '123', result: {} }
+      expect(isNotification(response)).toBe(false)
+    })
+
+    it('should return false for invalid objects', () => {
+      expect(isNotification(null)).toBe(false)
+      expect(isNotification(undefined)).toBe(false)
+      expect(isNotification({})).toBe(false)
+    })
+  })
+
+  describe('Environment detection', () => {
+    it('should detect Node.js environment', () => {
+      expect(isNode()).toBe(true)
+    })
+
+    it('should not detect browser environment in Node.js', () => {
+      expect(isBrowser()).toBe(false)
+    })
   })
 })