🧪 Add test for initWasm error path

.gitignore

@@ -1,2 +1,3 @@
 __pycache__/
 *.pyc
+node_modules/

docs/index.test.js

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+const fs = require('fs');
+const path = require('path');
+const { JSDOM } = require('jsdom');
+
+describe('Universal Image Converter', () => {
+    let dom;
+    let document;
+    let window;
+
+    beforeEach(async () => {
+        const htmlPath = path.resolve(__dirname, 'index.html');
+        const htmlContent = fs.readFileSync(htmlPath, 'utf8');
+
+        // We need runScripts: "dangerously" to use window.eval
+        dom = new JSDOM(htmlContent, {
+            runScripts: "dangerously"
+        });
+        document = dom.window.document;
+        window = dom.window;
+    });
+
+    test('should display error message when initWasm fails', async () => {
+        const htmlPath = path.resolve(__dirname, 'index.html');
+        const htmlContent = fs.readFileSync(htmlPath, 'utf8');
+
+        const scriptContent = htmlContent.match(/<script type="module">([\s\S]*?)<\/script>/)[1];
+
+        window.fetch = jest.fn(() => Promise.reject(new Error("Network Error")));
+
+        const initWasmStr = scriptContent.match(/async function initWasm\(\) \{[\s\S]*?\n        \}/)[0];
+
+        window.eval(`
+            ${initWasmStr}
+
+            window.testInitWasm = initWasm;
+
+            window.isEngineReady = false;
+            window.convertBtn = document.getElementById('convertBtn');
+            window.statusDiv = document.getElementById('status');
+            window.initializeImageMagick = async function() {};
+        `);
+
+        const originalError = console.error;
+        console.error = jest.fn();
+
+        await window.testInitWasm();
+
+        expect(window.statusDiv.textContent).toBe("Failed to initialize ImageMagick WASM engine.");
+        expect(window.fetch).toHaveBeenCalledWith("https://unpkg.com/@imagemagick/magick-wasm@0.0.30/dist/magick.wasm");
+        expect(console.error).toHaveBeenCalledWith(expect.any(Error));
+
+        console.error = originalError;
+    });
+});

jest.config.js

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+module.exports = {
+  testEnvironment: "jsdom",
+  setupFiles: ["./setupJest.js"]
+};