MCP Image Extractor

import { describe, it, expect, beforeEach } from '@jest/globals'; import { extractImageFromBase64 } from '../src/image-utils'; describe('Base64 Image Extraction Tests', () => { // Valid PNG image in base64 format (1x1 transparent pixel) const validPngBase64 = 'iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR42mNkYAAAAAYAAjCB0C8AAAAASUVORK5CYII='; // Invalid base64 string const invalidBase64 = 'this-is-not-base64!'; it('successfully processes valid base64 image data', async () => { const result = await extractImageFromBase64({ base64: validPngBase64, mime_type: 'image/png', resize: true, max_width: 800, max_height: 800 }); // Validate the result expect(result.isError).toBeUndefined(); 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).toBe('image/png'); }); it('handles invalid base64 data', async () => { const result = await extractImageFromBase64({ base64: invalidBase64, mime_type: 'image/png', resize: true, max_width: 800, max_height: 800 }); // Should return an error expect(result.isError).toBe(true); expect(result.content[0].text).toContain('Error: Invalid base64 string'); }); it('compresses base64 images', async () => { // Generate a larger base64 image (larger than our 1x1 pixel) // We'll simulate this with the existing base64 string repeated const largerBase64 = validPngBase64.repeat(10); const result = await extractImageFromBase64({ base64: largerBase64, mime_type: 'image/png', resize: true, max_width: 800, max_height: 800 }); // Validate the result includes compressed data const metadata = JSON.parse(result.content[0].text as string); // The compressed size should be reported in the metadata expect(metadata.size).toBeDefined(); // The output base64 should be different from input // (due to compression and/or resizing) expect(result.content[1].data).not.toBe(largerBase64); }); });