MCP Image Extractor

import { describe, it, expect, beforeEach } from '@jest/globals'; import * as fs from 'fs'; import * as path from 'path'; import { extractImageFromFile } from '../src/image-utils'; // Test file paths const TEST_IMAGE_PATH = path.join(__dirname, '../test_image.png'); describe('Image Extractor File Tests', () => { let originalReadFileSync: typeof fs.readFileSync; let originalExistsSync: typeof fs.existsSync; beforeEach(() => { // Save original functions originalReadFileSync = fs.readFileSync; originalExistsSync = fs.existsSync; }); afterEach(() => { // Restore original functions (fs as any).readFileSync = originalReadFileSync; (fs as any).existsSync = originalExistsSync; }); it('extracts image from file', async () => { // Only run this test if the test file exists if (fs.existsSync(TEST_IMAGE_PATH)) { const result = await extractImageFromFile({ file_path: TEST_IMAGE_PATH, resize: true, max_width: 800, max_height: 800 }); // Basic validation of the result expect(result).toBeDefined(); expect(result.content).toHaveLength(2); // Validate metadata const metadata = JSON.parse(result.content[0].text as string); expect(metadata.width).toBeDefined(); expect(metadata.height).toBeDefined(); expect(metadata.format).toBeDefined(); expect(metadata.size).toBeDefined(); // Validate image data expect(result.content[1].type).toBe('image'); expect(result.content[1].data).toBeDefined(); expect(result.content[1].mimeType).toBeDefined(); } else { console.warn(`Test file not found: ${TEST_IMAGE_PATH}`); } }); it('handles non-existent files', async () => { // Mock fs.existsSync to return false (fs as any).existsSync = jest.fn().mockReturnValue(false); const result = await extractImageFromFile({ file_path: 'non-existent-file.png', resize: true, max_width: 800, max_height: 800 }); expect(result.isError).toBe(true); expect(result.content[0].text).toContain('does not exist'); }); it('handles file reading errors', async () => { // Mock fs.existsSync to return true but fs.readFileSync to throw (fs as any).existsSync = jest.fn().mockReturnValue(true); (fs as any).readFileSync = jest.fn().mockImplementation(() => { throw new Error('Simulated read error'); }); const result = await extractImageFromFile({ file_path: 'error-file.png', resize: true, max_width: 800, max_height: 800 }); expect(result.isError).toBe(true); expect(result.content[0].text).toContain('Error:'); }); it('handles base64 encoding from test.js', async () => { // Only run this test if the test file exists if (fs.existsSync(TEST_IMAGE_PATH)) { const result = await extractImageFromFile({ file_path: TEST_IMAGE_PATH, resize: true, max_width: 800, max_height: 800 }); // Validate base64 data expect(result.content[1].data).toBeDefined(); expect(typeof result.content[1].data).toBe('string'); // Basic validation that it's a base64 string const base64Data = result.content[1].data as string; expect(base64Data.length % 4).toBe(0); // Base64 length multiple of 4 } else { console.warn(`Test file not found: ${TEST_IMAGE_PATH}`); } }); it('compresses images to reduce file size', async () => { // Only run this test if the test file exists if (fs.existsSync(TEST_IMAGE_PATH)) { // Get original file size const originalSize = fs.statSync(TEST_IMAGE_PATH).size; // Extract and compress the image const result = await extractImageFromFile({ file_path: TEST_IMAGE_PATH, resize: true, max_width: 800, max_height: 800 }); // Get metadata with compressed size const metadata = JSON.parse(result.content[0].text as string); console.log(`Original size: ${originalSize}, Compressed size: ${metadata.size}`); // The compressed size should be smaller than the original expect(metadata.size).toBeLessThan(originalSize); } else { console.warn(`Test file not found: ${TEST_IMAGE_PATH}`); } }); });