Android UI Assist MCP Server

import { getPNGDimensions, binaryToBase64, captureScreenshotResponse, } from '../../src/utils/screenshot'; import { captureScreenshot } from '../../src/utils/adb'; // Mock captureScreenshot jest.mock('../../src/utils/adb', () => ({ captureScreenshot: jest.fn(), })); describe('Screenshot Utilities', () => { const mockCaptureScreenshot = captureScreenshot as jest.MockedFunction<typeof captureScreenshot>; beforeEach(() => { jest.clearAllMocks(); }); describe('getPNGDimensions', () => { it('should correctly extract dimensions from PNG data', () => { // Create a minimal PNG with known dimensions (100x200) // PNG signature + IHDR chunk with width=100, height=200 const pngData = Buffer.from([ 0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a, // PNG signature 0x00, 0x00, 0x00, 0x0d, // IHDR chunk size (13 bytes) 0x49, 0x48, 0x44, 0x52, // IHDR chunk type 0x00, 0x00, 0x00, 0x64, // Width: 100 0x00, 0x00, 0x00, 0xc8, // Height: 200 0x08, // Bit depth: 8 0x02, // Color type: RGB 0x00, // Compression method: 0 0x00, // Filter method: 0 0x00, // Interlace method: 0 0x00, 0x00, 0x00, 0x00, // CRC (not needed for this test) ]); const dimensions = getPNGDimensions(pngData); expect(dimensions.width).toBe(100); expect(dimensions.height).toBe(200); }); it('should throw error for invalid PNG data', () => { const invalidData = Buffer.from([0x00, 0x01, 0x02, 0x03]); expect(() => getPNGDimensions(invalidData)).toThrow('Invalid PNG data'); }); it('should throw error for PNG data that is too short', () => { const shortData = Buffer.from([0x89, 0x50, 0x4e, 0x47]); expect(() => getPNGDimensions(shortData)).toThrow('Invalid PNG data'); }); }); describe('binaryToBase64', () => { it('should correctly convert binary data to base64', () => { const binaryData = Buffer.from('Hello, World!', 'utf-8'); const expectedBase64 = Buffer.from('Hello, World!', 'utf-8').toString('base64'); const result = binaryToBase64(binaryData); expect(result).toBe(expectedBase64); }); it('should handle empty buffer', () => { const emptyBuffer = Buffer.alloc(0); const result = binaryToBase64(emptyBuffer); expect(result).toBe(''); }); }); describe('captureScreenshotResponse', () => { it('should capture screenshot and return formatted response', async () => { // Create a minimal PNG with known dimensions (100x200) const pngData = Buffer.from([ 0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a, // PNG signature 0x00, 0x00, 0x00, 0x0d, // IHDR chunk size (13 bytes) 0x49, 0x48, 0x44, 0x52, // IHDR chunk type 0x00, 0x00, 0x00, 0x64, // Width: 100 0x00, 0x00, 0x00, 0xc8, // Height: 200 0x08, // Bit depth: 8 0x02, // Color type: RGB 0x00, // Compression method: 0 0x00, // Filter method: 0 0x00, // Interlace method: 0 0x00, 0x00, 0x00, 0x00, // CRC (not needed for this test) ]); mockCaptureScreenshot.mockReturnValue(pngData.toString('binary')); // Mock Date.now() to get consistent timestamp const originalDateNow = Date.now; Date.now = jest.fn(() => 1634567890123); const result = await captureScreenshotResponse('emulator-5554'); expect(result).toEqual({ data: pngData.toString('base64'), format: 'png', width: 100, height: 200, deviceId: 'emulator-5554', timestamp: 1634567890123, }); expect(mockCaptureScreenshot).toHaveBeenCalledWith('emulator-5554'); // Restore Date.now Date.now = originalDateNow; }); it('should use default deviceId if not provided', async () => { const pngData = Buffer.from([ 0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a, // PNG signature 0x00, 0x00, 0x00, 0x0d, // IHDR chunk size (13 bytes) 0x49, 0x48, 0x44, 0x52, // IHDR chunk type 0x00, 0x00, 0x00, 0x64, // Width: 100 0x00, 0x00, 0x00, 0xc8, // Height: 200 0x08, // Bit depth: 8 0x02, // Color type: RGB 0x00, // Compression method: 0 0x00, // Filter method: 0 0x00, // Interlace method: 0 0x00, 0x00, 0x00, 0x00, // CRC (not needed for this test) ]); mockCaptureScreenshot.mockReturnValue(pngData.toString('binary')); const result = await captureScreenshotResponse(); expect(result.deviceId).toBe('default'); expect(mockCaptureScreenshot).toHaveBeenCalledWith(undefined); }); it('should throw error if screenshot capture fails', async () => { mockCaptureScreenshot.mockImplementation(() => { throw new Error('Failed to capture screenshot'); }); await expect(captureScreenshotResponse('emulator-5554')).rejects.toThrow( 'Failed to capture screenshot: Failed to capture screenshot' ); }); }); });