Replace Buffer usage with Uint8Array (#633)

Co-authored-by: Borewit <Borewit@users.noreply.github.com>

core.d.ts

@@ -323,13 +323,13 @@ export type ReadableStreamWithFileType = ReadableStream & {
 };
 
 /**
-Detect the file type of a `Buffer`, `Uint8Array`, or `ArrayBuffer`.
+Detect the file type of a `Uint8Array`, or `ArrayBuffer`.
 
 The file type is detected by checking the [magic number](https://en.wikipedia.org/wiki/Magic_number_(programming)#Magic_numbers_in_files) of the buffer.
 
 If file access is available, it is recommended to use `.fromFile()` instead.
 
-@param buffer - An Uint8Array or Buffer representing file data. It works best if the buffer contains the entire file. It may work with a smaller portion as well.
+@param buffer - An Uint8Array or ArrayBuffer representing file data. It works best if the buffer contains the entire file. It may work with a smaller portion as well.
 @returns The detected file type, or `undefined` when there is no match.
 */
 export function fileTypeFromBuffer(buffer: Uint8Array | ArrayBuffer): Promise<FileTypeResult | undefined>;

core.js

@@ -1,6 +1,6 @@
-import {Buffer} from 'node:buffer';
 import * as Token from 'token-types';
 import * as strtok3 from 'strtok3/core';
+import {includes, indexOf, getUintBE} from 'uint8array-extras';
 import {
  stringToBytes,
  tarHeaderChecksumMatches,
@@ -75,7 +75,7 @@ export class FileTypeParser {
 
  async fromBuffer(input) {
  if (!(input instanceof Uint8Array || input instanceof ArrayBuffer)) {
- throw new TypeError(`Expected the \`input\` argument to be of type \`Uint8Array\` or \`Buffer\` or \`ArrayBuffer\`, got \`${typeof input}\``);
+ throw new TypeError(`Expected the \`input\` argument to be of type \`Uint8Array\` or \`ArrayBuffer\`, got \`${typeof input}\``);
  }
 
  const buffer = input instanceof Uint8Array ? input : new Uint8Array(input);
@@ -116,7 +116,7 @@ export class FileTypeParser {
  const outputStream = stream.pipeline ? stream.pipeline(readableStream, pass, () => {}) : readableStream.pipe(pass);
 
  // Read the input stream and detect the filetype
- const chunk = readableStream.read(sampleSize) ?? readableStream.read() ?? Buffer.alloc(0);
+ const chunk = readableStream.read(sampleSize) ?? readableStream.read() ?? new Uint8Array(0);
  try {
  pass.fileType = await this.fromBuffer(chunk);
  } catch (error) {
@@ -145,7 +145,7 @@ export class FileTypeParser {
  }
 
  async parse(tokenizer) {
- this.buffer = Buffer.alloc(minimumBytes);
+ this.buffer = new Uint8Array(minimumBytes);
 
  // Keep reading until EOF if the file size is unknown.
  if (tokenizer.fileInfo.size === undefined) {
@@ -372,12 +372,14 @@ export class FileTypeParser {
  while (tokenizer.position + 30 < tokenizer.fileInfo.size) {
  await tokenizer.readBuffer(this.buffer, {length: 30});
 
+ const view = new DataView(this.buffer.buffer);
+
  // https://en.wikipedia.org/wiki/Zip_(file_format)#File_headers
  const zipHeader = {
- compressedSize: this.buffer.readUInt32LE(18),
- uncompressedSize: this.buffer.readUInt32LE(22),
- filenameLength: this.buffer.readUInt16LE(26),
- extraFieldLength: this.buffer.readUInt16LE(28),
+ compressedSize: view.getUint32(18, true),
+ uncompressedSize: view.getUint32(22, true),
+ filenameLength: view.getUint16(26, true),
+ extraFieldLength: view.getUint16(28, true),
  };
 
  zipHeader.filename = await tokenizer.readToken(new Token.StringType(zipHeader.filenameLength, 'utf-8'));
@@ -472,7 +474,8 @@ export class FileTypeParser {
  while (nextHeaderIndex < 0 && (tokenizer.position < tokenizer.fileInfo.size)) {
  await tokenizer.peekBuffer(this.buffer, {mayBeLess: true});
 
- nextHeaderIndex = this.buffer.indexOf('504B0304', 0, 'hex');
+ nextHeaderIndex = indexOf(this.buffer, new Uint8Array([0x50, 0x4B, 0x03, 0x04]));
+
  // Move position to the next header if found, skip the whole buffer otherwise
  await tokenizer.ignore(nextHeaderIndex >= 0 ? nextHeaderIndex : this.buffer.length);
  }
@@ -495,7 +498,7 @@ export class FileTypeParser {
  if (this.checkString('OggS')) {
  // This is an OGG container
  await tokenizer.ignore(28);
- const type = Buffer.alloc(8);
+ const type = new Uint8Array(8);
  await tokenizer.readBuffer(type);
 
  // Needs to be before `ogg` check
@@ -576,7 +579,7 @@ export class FileTypeParser {
  ) {
  // They all can have MIME `video/mp4` except `application/mp4` special-case which is hard to detect.
  // For some cases, we're specific, everything else falls to `video/mp4` with `mp4` extension.
- const brandMajor = this.buffer.toString('binary', 8, 12).replace('\0', ' ').trim();
+ const brandMajor = new Token.StringType(4, 'latin1').get(this.buffer, 8).replace('\0', ' ').trim();
  switch (brandMajor) {
  case 'avif':
  case 'avis':
@@ -706,11 +709,11 @@ export class FileTypeParser {
  try {
  await tokenizer.ignore(1350);
  const maxBufferSize = 10 * 1024 * 1024;
- const buffer = Buffer.alloc(Math.min(maxBufferSize, tokenizer.fileInfo.size));
+ const buffer = new Uint8Array(Math.min(maxBufferSize, tokenizer.fileInfo.size));
  await tokenizer.readBuffer(buffer, {mayBeLess: true});
 
  // Check if this is an Adobe Illustrator file
- if (buffer.includes(Buffer.from('AIPrivateData'))) {
+ if (includes(buffer, new TextEncoder().encode('AIPrivateData'))) {
  return {
  ext: 'ai',
  mime: 'application/postscript',
@@ -765,35 +768,39 @@ export class FileTypeParser {
  async function readField() {
  const msb = await tokenizer.peekNumber(Token.UINT8);
  let mask = 0x80;
- let ic = 0; // 0 = A, 1 = B, 2 = C, 3
- // = D
+ let ic = 0; // 0 = A, 1 = B, 2 = C, 3 = D
 
  while ((msb & mask) === 0 && mask !== 0) {
  ++ic;
  mask >>= 1;
  }
 
- const id = Buffer.alloc(ic + 1);
+ const id = new Uint8Array(ic + 1);
  await tokenizer.readBuffer(id);
  return id;
  }
 
  async function readElement() {
- const id = await readField();
+ const idField = await readField();
  const lengthField = await readField();
+
  lengthField[0] ^= 0x80 >> (lengthField.length - 1);
  const nrLength = Math.min(6, lengthField.length); // JavaScript can max read 6 bytes integer
+
+ const idView = new DataView(idField.buffer);
+ const lengthView = new DataView(lengthField.buffer, lengthField.length - nrLength, nrLength);
+
  return {
- id: id.readUIntBE(0, id.length),
- len: lengthField.readUIntBE(lengthField.length - nrLength, nrLength),
+ id: getUintBE(idView),
+ len: getUintBE(lengthView),
  };
  }
 
  async function readChildren(children) {
  while (children > 0) {
  const element = await readElement();
  if (element.id === 0x42_82) {
- const rawValue = await tokenizer.readToken(new Token.StringType(element.len, 'utf-8'));
+ const rawValue = await tokenizer.readToken(new Token.StringType(element.len));
  return rawValue.replaceAll(/\00.*$/g, ''); // Return DocType
  }
 
@@ -1059,7 +1066,7 @@ export class FileTypeParser {
  }
 
  if (this.checkString('AC')) {
- const version = this.buffer.toString('binary', 2, 6);
+ const version = new Token.StringType(4, 'latin1').get(this.buffer, 2);
  if (version.match('^d*') && version >= 1000 && version <= 1050) {
  return {
  ext: 'dwg',
@@ -1126,7 +1133,7 @@ export class FileTypeParser {
  async function readChunkHeader() {
  return {
  length: await tokenizer.readToken(Token.INT32_BE),
- type: await tokenizer.readToken(new Token.StringType(4, 'binary')),
+ type: await tokenizer.readToken(new Token.StringType(4, 'latin1')),
  };
  }
 
@@ -1213,7 +1220,7 @@ export class FileTypeParser {
  // ASF_Header_Object first 80 bytes
  if (this.check([0x30, 0x26, 0xB2, 0x75, 0x8E, 0x66, 0xCF, 0x11, 0xA6, 0xD9])) {
  async function readHeader() {
- const guid = Buffer.alloc(16);
+ const guid = new Uint8Array(16);
  await tokenizer.readBuffer(guid);
  return {
  id: guid,
@@ -1228,7 +1235,7 @@ export class FileTypeParser {
  let payload = header.size - 24;
  if (_check(header.id, [0x91, 0x07, 0xDC, 0xB7, 0xB7, 0xA9, 0xCF, 0x11, 0x8E, 0xE6, 0x00, 0xC0, 0x0C, 0x20, 0x53, 0x65])) {
  // Sync on Stream-Properties-Object (B7DC0791-A9B7-11CF-8EE6-00C00C205365)
- const typeId = Buffer.alloc(16);
+ const typeId = new Uint8Array(16);
  payload -= await tokenizer.readBuffer(typeId);
 
  if (_check(typeId, [0x40, 0x9E, 0x69, 0xF8, 0x4D, 0x5B, 0xCF, 0x11, 0xA8, 0xFD, 0x00, 0x80, 0x5F, 0x5C, 0x44, 0x2B])) {
@@ -1432,10 +1439,11 @@ export class FileTypeParser {
  }
 
  if (this.check([0x04, 0x00, 0x00, 0x00]) && this.buffer.length >= 16) { // Rough & quick check Pickle/ASAR
- const jsonSize = this.buffer.readUInt32LE(12);
+ const jsonSize = new DataView(this.buffer.buffer).getUint32(12, true);
+
  if (jsonSize > 12 && this.buffer.length >= jsonSize + 16) {
  try {
- const header = this.buffer.slice(16, jsonSize + 16).toString();
+ const header = new TextDecoder().decode(this.buffer.slice(16, jsonSize + 16));
  const json = JSON.parse(header);
  // Check if Pickle is ASAR
  if (json.files) { // Final check, assuring Pickle/ASAR format

index.test-d.ts

@@ -1,4 +1,3 @@
-import {Buffer} from 'node:buffer';
 import {createReadStream} from 'node:fs';
 import {expectType} from 'tsd';
 import {
@@ -18,12 +17,11 @@ import {
  type MimeType,
 } from './index.js';
 
-expectType<Promise<FileTypeResult | undefined>>(fileTypeFromBuffer(Buffer.from([0xFF, 0xD8, 0xFF])));
 expectType<Promise<FileTypeResult | undefined>>(fileTypeFromBuffer(new Uint8Array([0xFF, 0xD8, 0xFF])));
 expectType<Promise<FileTypeResult | undefined>>(fileTypeFromBuffer(new ArrayBuffer(42)));
 
 (async () => {
- const result = await fileTypeFromBuffer(Buffer.from([0xFF, 0xD8, 0xFF]));
+ const result = await fileTypeFromBuffer(new Uint8Array([0xFF, 0xD8, 0xFF]));
  if (result !== undefined) {
  expectType<FileExtension>(result.ext);
  expectType<MimeType>(result.mime);

package.json

@@ -1,7 +1,7 @@
 {
  "name": "file-type",
  "version": "19.0.0",
- "description": "Detect the file type of a Buffer/Uint8Array/ArrayBuffer",
+ "description": "Detect the file type of a Uint8Array/ArrayBuffer",
  "license": "MIT",
  "repository": "sindresorhus/file-type",
  "funding": "https://github.com/sindresorhus/file-type?sponsor=1",
@@ -211,8 +211,9 @@
  ],
  "dependencies": {
  "readable-web-to-node-stream": "^3.0.2",
- "strtok3": "^7.0.0",
- "token-types": "^5.0.1"
+ "strtok3": "^7.1.0",
+ "token-types": "^6.0.0",
+ "uint8array-extras": "^1.3.0"
  },
  "devDependencies": {
  "@tokenizer/token": "^0.3.0",

readme.md

@@ -1,6 +1,6 @@
 # file-type
 
-> Detect the file type of a Buffer/Uint8Array/ArrayBuffer
+> Detect the file type of a Uint8Array/ArrayBuffer
 
 The file type is detected by checking the [magic number](https://en.wikipedia.org/wiki/Magic_number_(programming)#Magic_numbers_in_files) of the buffer.
 
@@ -31,7 +31,7 @@ console.log(await fileTypeFromFile('Unicorn.png'));
 //=> {ext: 'png', mime: 'image/png'}
 ```
 
-Determine file type from a Buffer, which may be a portion of the beginning of a file:
+Determine file type from a Uint8Array/ArrayBuffer, which may be a portion of the beginning of a file:
 
 ```js
 import {fileTypeFromBuffer} from 'file-type';
@@ -107,7 +107,7 @@ console.log(fileType);
 
 ### fileTypeFromBuffer(buffer)
 
-Detect the file type of a `Buffer`, `Uint8Array`, or `ArrayBuffer`.
+Detect the file type of a `Uint8Array`, or `ArrayBuffer`.
 
 The file type is detected by checking the [magic number](https://en.wikipedia.org/wiki/Magic_number_(programming)#Magic_numbers_in_files) of the buffer.
 
@@ -122,7 +122,7 @@ Or `undefined` when there is no match.
 
 #### buffer
 
-Type: `Buffer | Uint8Array | ArrayBuffer`
+Type: `Uint8Array | ArrayBuffer`
 
 A buffer representing file data. It works best if the buffer contains the entire file. It may work with a smaller portion as well.
 
@@ -335,7 +335,7 @@ const customDetectors = [
  async tokenizer => {
  const unicornHeader = [85, 78, 73, 67, 79, 82, 78]; // 'UNICORN' as decimal string
 
- const buffer = Buffer.alloc(7);
+ const buffer = new Uint8Array(7);
  await tokenizer.peekBuffer(buffer, {length: unicornHeader.length, mayBeLess: true});
 
  if (unicornHeader.every((value, index) => value === buffer[index])) {
@@ -346,7 +346,7 @@ const customDetectors = [
  },
 ];
 
-const buffer = Buffer.from('UNICORN');
+const buffer = new Uint8Array(new TextEncoder().encode('UNICORN'));
 const parser = new FileTypeParser({customDetectors});
 const fileType = await parser.fromBuffer(buffer);
 console.log(fileType);