test: migrate test suite from Jest to Bun test framework

- Convert test files to use Bun's test framework and mocking utilities
- Update import statements and test syntax
- Add comprehensive test utilities and mock implementations
- Create test migration guide documentation
- Implement helper functions for consistent test setup and teardown
- Add type definitions for improved type safety in tests

__tests__/core/server.test.ts

@@ -0,0 +1,77 @@
+import { describe, expect, test, beforeEach, afterEach, mock } from "bun:test";
+import {
+    type MockLiteMCPInstance,
+    type Tool,
+    createMockLiteMCPInstance,
+    createMockServices,
+    setupTestEnvironment,
+    cleanupMocks
+} from '../utils/test-utils';
+
+describe('Home Assistant MCP Server', () => {
+    let liteMcpInstance: MockLiteMCPInstance;
+    let addToolCalls: Tool[];
+    let mocks: ReturnType<typeof setupTestEnvironment>;
+
+    beforeEach(async () => {
+        // Setup test environment
+        mocks = setupTestEnvironment();
+        liteMcpInstance = createMockLiteMCPInstance();
+
+        // Import the module which will execute the main function
+        await import('../../src/index.js');
+
+        // Get the mock instance and tool calls
+        addToolCalls = liteMcpInstance.addTool.mock.calls.map(call => call.args[0]);
+    });
+
+    afterEach(() => {
+        cleanupMocks({ liteMcpInstance, ...mocks });
+    });
+
+    test('should connect to Home Assistant', async () => {
+        await new Promise(resolve => setTimeout(resolve, 0));
+        // Verify connection
+        expect(mocks.mockFetch.mock.calls.length).toBeGreaterThan(0);
+        expect(liteMcpInstance.start.mock.calls.length).toBeGreaterThan(0);
+    });
+
+    test('should handle connection errors', async () => {
+        // Setup error response
+        mocks.mockFetch = mock(() => Promise.reject(new Error('Connection failed')));
+        globalThis.fetch = mocks.mockFetch;
+
+        // Import module again with error mock
+        await import('../../src/index.js');
+
+        // Verify error handling
+        expect(mocks.mockFetch.mock.calls.length).toBeGreaterThan(0);
+        expect(liteMcpInstance.start.mock.calls.length).toBe(0);
+    });
+
+    describe('Tool Registration', () => {
+        test('should register all required tools', () => {
+            const toolNames = addToolCalls.map(tool => tool.name);
+
+            expect(toolNames).toContain('list_devices');
+            expect(toolNames).toContain('control');
+            expect(toolNames).toContain('get_history');
+            expect(toolNames).toContain('scene');
+            expect(toolNames).toContain('notify');
+            expect(toolNames).toContain('automation');
+            expect(toolNames).toContain('addon');
+            expect(toolNames).toContain('package');
+            expect(toolNames).toContain('automation_config');
+        });
+
+        test('should configure tools with correct parameters', () => {
+            const listDevicesTool = addToolCalls.find(tool => tool.name === 'list_devices');
+            expect(listDevicesTool).toBeDefined();
+            expect(listDevicesTool?.parameters).toBeDefined();
+
+            const controlTool = addToolCalls.find(tool => tool.name === 'control');
+            expect(controlTool).toBeDefined();
+            expect(controlTool?.parameters).toBeDefined();
+        });
+    });
+});