Add TIFF parser and buffer-based image size APIs

Introduce a TIFF parser and integrate it into the image detection/size parsing pipeline. Add buffer-based APIs (detectImageTypeFromBuffer, imageSizeFromBuffer, imageSizeFromBufferFallBack) and a helper to convert Buffer to a Readable stream; refactor parser registry into a type-to-parser map and a first-byte fast-path map for quicker detection. Harden WebP parsing with safer length checks. Add sample image resources and a comprehensive Vitest test suite (packages/napcat-test) with updated package dependency and resolve aliases. pnpm-lock updated to link the new package.

packages/napcat-image-size/src/index.ts

@@ -2,9 +2,11 @@ import { BmpParser } from '@/napcat-image-size/src/parser/BmpParser';
 import { GifParser } from '@/napcat-image-size/src/parser/GifParser';
 import { JpegParser } from '@/napcat-image-size/src/parser/JpegParser';
 import { PngParser } from '@/napcat-image-size/src/parser/PngParser';
+import { TiffParser } from '@/napcat-image-size/src/parser/TiffParser';
 import { WebpParser } from '@/napcat-image-size/src/parser/WebpParser';
 import * as fs from 'fs';
 import { ReadStream } from 'fs';
+import { Readable } from 'stream';
 
 export interface ImageSize {
   width: number;
@@ -17,6 +19,7 @@ export enum ImageType {
   BMP = 'bmp',
   GIF = 'gif',
   WEBP = 'webp',
+  TIFF = 'tiff',
   UNKNOWN = 'unknown',
 }
 
@@ -40,13 +43,39 @@ export function matchMagic (buffer: Buffer, magic: number[], offset = 0): boolea
   return true;
 }
 
-const parsers: ReadonlyArray<ImageParser> = [
-  new PngParser(),
-  new JpegParser(),
-  new BmpParser(),
-  new GifParser(),
-  new WebpParser(),
-];
+// 所有解析器实例
+const parserInstances = {
+  png: new PngParser(),
+  jpeg: new JpegParser(),
+  bmp: new BmpParser(),
+  gif: new GifParser(),
+  webp: new WebpParser(),
+  tiff: new TiffParser(),
+};
+
+// 首字节到可能的图片类型映射，用于快速筛选
+const firstByteMap = new Map<number, ImageType[]>([
+  [0x42, [ImageType.BMP]],       // 'B' - BMP
+  [0x47, [ImageType.GIF]],       // 'G' - GIF
+  [0x49, [ImageType.TIFF]],      // 'I' - TIFF (II - little endian)
+  [0x4D, [ImageType.TIFF]],      // 'M' - TIFF (MM - big endian)
+  [0x52, [ImageType.WEBP]],      // 'R' - RIFF (WebP)
+  [0x89, [ImageType.PNG]],       // PNG signature
+  [0xFF, [ImageType.JPEG]],      // JPEG SOI
+]);
+
+// 类型到解析器的映射
+const typeToParser = new Map<ImageType, ImageParser>([
+  [ImageType.PNG, parserInstances.png],
+  [ImageType.JPEG, parserInstances.jpeg],
+  [ImageType.BMP, parserInstances.bmp],
+  [ImageType.GIF, parserInstances.gif],
+  [ImageType.WEBP, parserInstances.webp],
+  [ImageType.TIFF, parserInstances.tiff],
+]);
+
+// 所有解析器列表（用于回退）
+const parsers: ReadonlyArray<ImageParser> = Object.values(parserInstances);
 
 export async function detectImageType (filePath: string): Promise<ImageType> {
   return new Promise((resolve, reject) => {
@@ -56,18 +85,22 @@ export async function detectImageType (filePath: string): Promise<ImageType> {
       end: 63,
     });
 
-    let buffer: Buffer | null = null;
+    const chunks: Buffer[] = [];
 
-    stream.once('error', (err) => {
+    stream.on('error', (err) => {
       stream.destroy();
       reject(err);
     });
 
-    stream.once('readable', () => {
-      buffer = stream.read(64) as Buffer;
-      stream.destroy();
+    stream.on('data', (chunk: Buffer | string) => {
+      const chunkBuffer = Buffer.isBuffer(chunk) ? chunk : Buffer.from(chunk);
+      chunks.push(chunkBuffer);
+    });
 
-      if (!buffer) {
+    stream.on('end', () => {
+      const buffer = Buffer.concat(chunks);
+
+      if (buffer.length === 0) {
         return resolve(ImageType.UNKNOWN);
       }
 
@@ -79,12 +112,6 @@ export async function detectImageType (filePath: string): Promise<ImageType> {
 
       resolve(ImageType.UNKNOWN);
     });
-
-    stream.once('end', () => {
-      if (!buffer) {
-        resolve(ImageType.UNKNOWN);
-      }
-    });
   });
 }
 
@@ -92,7 +119,7 @@ export async function imageSizeFromFile (filePath: string): Promise<ImageSize |
   try {
     // 先检测类型
     const type = await detectImageType(filePath);
-    const parser = parsers.find(p => p.type === type);
+    const parser = typeToParser.get(type);
     if (!parser) {
       return undefined;
     }
@@ -124,3 +151,71 @@ export async function imageSizeFallBack (
 ): Promise<ImageSize> {
   return await imageSizeFromFile(filePath) ?? fallback;
 }
+
+// 从 Buffer 创建可读流
+function bufferToReadStream (buffer: Buffer): ReadStream {
+  const readable = new Readable({
+    read () {
+      this.push(buffer);
+      this.push(null);
+    }
+  });
+  return readable as unknown as ReadStream;
+}
+
+// 从 Buffer 检测图片类型（使用首字节快速筛选）
+export function detectImageTypeFromBuffer (buffer: Buffer): ImageType {
+  if (buffer.length === 0) {
+    return ImageType.UNKNOWN;
+  }
+
+  const firstByte = buffer[0]!;
+  const possibleTypes = firstByteMap.get(firstByte);
+
+  if (possibleTypes) {
+    // 根据首字节快速筛选可能的类型
+    for (const type of possibleTypes) {
+      const parser = typeToParser.get(type);
+      if (parser && parser.canParse(buffer)) {
+        return parser.type;
+      }
+    }
+  }
+
+  // 回退：遍历所有解析器
+  for (const parser of parsers) {
+    if (parser.canParse(buffer)) {
+      return parser.type;
+    }
+  }
+
+  return ImageType.UNKNOWN;
+}
+
+// 从 Buffer 解析图片尺寸
+export async function imageSizeFromBuffer (buffer: Buffer): Promise<ImageSize | undefined> {
+  const type = detectImageTypeFromBuffer(buffer);
+  const parser = typeToParser.get(type);
+  if (!parser) {
+    return undefined;
+  }
+
+  try {
+    const stream = bufferToReadStream(buffer);
+    return await parser.parseSize(stream);
+  } catch (err) {
+    console.error(`解析图片尺寸出错: ${err}`);
+    return undefined;
+  }
+}
+
+// 从 Buffer 解析图片尺寸，带回退值
+export async function imageSizeFromBufferFallBack (
+  buffer: Buffer,
+  fallback: ImageSize = {
+    width: 1024,
+    height: 1024,
+  }
+): Promise<ImageSize> {
+  return await imageSizeFromBuffer(buffer) ?? fallback;
+}