brand new unit tests finally

src/utils/checksum.ts

@@ -48,7 +48,9 @@ export const generateFileChecksum = async (file: File): Promise<string> => {
         console.error('crypto.subtle is not available in this environment. SHA-256 generation will fail.');
     }
 
-    const hashBuffer = await crypto.subtle.digest('SHA-256', buffer);
+    // Ensure buffer is a TypedArray or ArrayBuffer that crypto.subtle accepts
+    // Wrapping in Uint8Array handles both ArrayBuffer and SharedArrayBuffer, and helps with JSDOM compatibility
+    const hashBuffer = await crypto.subtle.digest('SHA-256', new Uint8Array(buffer));
     const hashArray = Array.from(new Uint8Array(hashBuffer));
     const hashHex = hashArray.map(b => b.toString(16).padStart(2, '0')).join('');
     return hashHex;

src/utils/pdfConverter.ts

@@ -42,13 +42,45 @@ const renderPageToImageFile = async (
   return new File([blob], newFileName, { type: 'image/jpeg' });
 };
 
+/**
+ * Helper to read file as ArrayBuffer using FileReader (fallback for environments missing file.arrayBuffer)
+ */
+const readFileAsArrayBuffer = (file: File): Promise<ArrayBuffer> => {
+  return new Promise((resolve, reject) => {
+    const reader = new FileReader();
+    reader.onload = () => {
+      if (reader.result instanceof ArrayBuffer) {
+        resolve(reader.result);
+      } else {
+        reject(new Error('FileReader result was not an ArrayBuffer'));
+      }
+    };
+    reader.onerror = () => {
+      reject(new Error(`FileReader error: ${reader.error?.message}`));
+    };
+    reader.readAsArrayBuffer(file);
+  });
+};
+
 /**
  * Fetches a PDF document from a File object.
  * @param pdfFile The PDF file.
  * @returns A promise that resolves to the pdf.js document object.
  */
 const getPdfDocument = async (pdfFile: File) => {
-  const arrayBuffer = await pdfFile.arrayBuffer();
+  let arrayBuffer: ArrayBuffer;
+  
+  if (typeof pdfFile.arrayBuffer === 'function') {
+    try {
+      arrayBuffer = await pdfFile.arrayBuffer();
+    } catch (error) {
+       console.warn('pdfFile.arrayBuffer() failed, falling back to FileReader', error);
+       arrayBuffer = await readFileAsArrayBuffer(pdfFile);
+    }
+  } else {
+    arrayBuffer = await readFileAsArrayBuffer(pdfFile);
+  }
+
   const pdf: PDFDocumentProxy = await pdfjsLib.getDocument(arrayBuffer).promise;
   return pdf;
 };