fix: replace Node.js Buffer APIs with browser-native alternatives

Buffer.from, Buffer.isBuffer, and buffer-crc32 crash in browser/CDN
environments. Use Uint8Array, ArrayBuffer.isView, TextEncoder, and a
custom CRC32 table instead.

Author: caio-pizzol

packages/super-editor/src/core/DocxZipper.js

@@ -1,6 +1,6 @@
 import * as xmljs from 'xml-js';
 import JSZip from 'jszip';
-import { getContentTypesFromXml } from './super-converter/helpers.js';
+import { getContentTypesFromXml, base64ToUint8Array } from './super-converter/helpers.js';
 import { ensureXmlString, isXmlLike } from './encoding-helpers.js';
 
 /**
@@ -303,7 +303,7 @@ class DocxZipper {
     });
 
     Object.keys(media).forEach((path) => {
-      const binaryData = Buffer.from(media[path], 'base64');
+      const binaryData = base64ToUint8Array(media[path]);
       zip.file(path, binaryData);
     });
 

packages/super-editor/src/core/super-converter/SuperConverter.js

@@ -1,9 +1,9 @@
+/* global TextEncoder */
 import * as xmljs from 'xml-js';
 import { v4 as uuidv4 } from 'uuid';
-import crc32 from 'buffer-crc32';
 import { DocxExporter, exportSchemaToJson } from './exporter';
 import { createDocumentJson, addDefaultStylesIfMissing } from './v2/importer/docxImporter.js';
-import { deobfuscateFont, getArrayBufferFromUrl } from './helpers.js';
+import { deobfuscateFont, getArrayBufferFromUrl, computeCrc32Hex } from './helpers.js';
 import { baseNumbering } from './v2/exporter/helpers/base-list.definitions.js';
 import { DEFAULT_CUSTOM_XML, DEFAULT_DOCX_DEFS } from './exporter-docx-defs.js';
 import {
@@ -758,9 +758,8 @@ class SuperConverter {
    */
   #generateIdentifierHash() {
     const combined = `${this.documentGuid}|${this.getDocumentCreatedTimestamp()}`;
-    const buffer = Buffer.from(combined, 'utf8');
-    const hash = crc32(buffer);
-    return `HASH-${hash.toString('hex').toUpperCase()}`;
+    const data = new TextEncoder().encode(combined);
+    return `HASH-${computeCrc32Hex(data).toUpperCase()}`;
   }
 
   /**
@@ -775,21 +774,21 @@ class SuperConverter {
     }
 
     try {
-      let buffer;
+      let data;
 
-      if (Buffer.isBuffer(this.fileSource)) {
-        buffer = this.fileSource;
+      if (ArrayBuffer.isView(this.fileSource)) {
+        const view = this.fileSource;
+        data = new Uint8Array(view.buffer, view.byteOffset, view.byteLength);
       } else if (this.fileSource instanceof ArrayBuffer) {
-        buffer = Buffer.from(this.fileSource);
+        data = new Uint8Array(this.fileSource);
       } else if (this.fileSource instanceof Blob || this.fileSource instanceof File) {
         const arrayBuffer = await this.fileSource.arrayBuffer();
-        buffer = Buffer.from(arrayBuffer);
+        data = new Uint8Array(arrayBuffer);
       } else {
         return `HASH-${uuidv4().replace(/-/g, '').substring(0, 8).toUpperCase()}`;
       }
 
-      const hash = crc32(buffer);
-      return `HASH-${hash.toString('hex').toUpperCase()}`;
+      return `HASH-${computeCrc32Hex(data).toUpperCase()}`;
     } catch (e) {
       console.warn('[super-converter] Could not generate content hash:', e);
       return `HASH-${uuidv4().replace(/-/g, '').substring(0, 8).toUpperCase()}`;

packages/super-editor/src/core/super-converter/helpers.js

@@ -1,6 +1,38 @@
 import { parseSizeUnit } from '../utilities/index.js';
 import { xml2js } from 'xml-js';
 
+// --- Browser-compatible CRC32 (replaces buffer-crc32 to avoid Node.js Buffer dependency) ---
+const CRC32_TABLE = new Uint32Array(256);
+for (let i = 0; i < 256; i++) {
+  let c = i;
+  for (let j = 0; j < 8; j++) {
+    c = c & 1 ? 0xedb88320 ^ (c >>> 1) : c >>> 1;
+  }
+  CRC32_TABLE[i] = c;
+}
+
+/**
+ * Compute CRC32 of a Uint8Array and return as 8-char lowercase hex string.
+ * Drop-in replacement for `buffer-crc32(buf).toString('hex')`.
+ */
+function computeCrc32Hex(data) {
+  let crc = 0xffffffff;
+  for (let i = 0; i < data.length; i++) {
+    crc = CRC32_TABLE[(crc ^ data[i]) & 0xff] ^ (crc >>> 8);
+  }
+  return ((crc ^ 0xffffffff) >>> 0).toString(16).padStart(8, '0');
+}
+
+/** Decode a base64 string to Uint8Array (works in both Node 16+ and browsers). */
+function base64ToUint8Array(base64) {
+  const binary = atob(base64);
+  const bytes = new Uint8Array(binary.length);
+  for (let i = 0; i < binary.length; i++) {
+    bytes[i] = binary.charCodeAt(i);
+  }
+  return bytes;
+}
+
 // CSS pixels per inch; used to convert between Word's inch-based measurements and DOM pixels.
 const PIXELS_PER_INCH = 96;
 
@@ -276,21 +308,7 @@ const getArrayBufferFromUrl = async (input) => {
   // If this is a data URI we need only the payload portion
   const base64Payload = isDataUri ? trimmed.split(',', 2)[1] : trimmed.replace(/\s/g, '');
 
-  try {
-    if (typeof globalThis.atob === 'function') {
-      const binary = globalThis.atob(base64Payload);
-      const bytes = new Uint8Array(binary.length);
-      for (let i = 0; i < binary.length; i++) {
-        bytes[i] = binary.charCodeAt(i);
-      }
-      return bytes.buffer;
-    }
-  } catch (err) {
-    console.warn('atob failed, falling back to Buffer:', err);
-  }
-
-  const buf = Buffer.from(base64Payload, 'base64');
-  return buf.buffer.slice(buf.byteOffset, buf.byteOffset + buf.byteLength);
+  return base64ToUint8Array(base64Payload).buffer;
 };
 
 const getContentTypesFromXml = (contentTypesXml) => {
@@ -620,4 +638,6 @@ export {
   convertSizeToCSS,
   resolveShadingFillColor,
   resolveOpcTargetPath,
+  computeCrc32Hex,
+  base64ToUint8Array,
 };