fix(processor): 修复 GIF 下载策略在开启格式转换时不生效的问题

Author: Shirolin

scratch_test.ts

@@ -0,0 +1,63 @@
+import { ImageItem, Settings } from "./src/types";
+
+// 模拟逻辑测试函数 (简化版，不包含 DOM 操作)
+function simulateConvertLogic(blobType: string, img: ImageItem, settings: Settings) {
+  const targetFormat = settings.downloadLogic?.targetFormat || "original";
+  const gifStrategy = settings.gifStrategy || "keep";
+  
+  const originalFormat = img.format.toLowerCase();
+  const actualMimeType = blobType.toLowerCase();
+
+  const isGif = originalFormat === "gif" || actualMimeType === "image/gif";
+  
+  let shouldConvert = false;
+  let extension = "png";
+  
+  // 模拟后缀逻辑
+  const urlExt = img.url.split(".").pop()?.split(/[?#]/)[0]?.toLowerCase();
+  if (originalFormat !== "unknown" && originalFormat.length <= 5) {
+    extension = originalFormat;
+  } else {
+    extension = urlExt && urlExt.length <= 5 ? urlExt : "png";
+  }
+  if (extension === "jpeg") extension = "jpg";
+
+  console.log(`- 输入: URL=${img.url}, SnifferFormat=${img.format}, BlobType=${blobType}`);
+  console.log(`- 识别结果: isGif=${isGif}, 策略=${gifStrategy}, 目标格式=${targetFormat}`);
+
+  if (isGif) {
+    if (gifStrategy === "keep") {
+      return { action: "KEEP", extension: "gif" };
+    } else if (gifStrategy === "firstFrame") {
+      shouldConvert = true;
+    } else if (gifStrategy === "skip") {
+      return { action: "SKIP" };
+    }
+  }
+
+  if (targetFormat !== "original") {
+    if (targetFormat !== originalFormat || isGif) {
+      shouldConvert = true;
+    }
+  }
+
+  return { action: shouldConvert ? "CONVERT" : "DOWNLOAD", extension };
+}
+
+// 测试用例
+const settings: Settings = {
+  gifStrategy: "keep",
+  downloadLogic: { targetFormat: "webp", quality: 80 }
+} as any;
+
+console.log("场景 1: GIF 保持原图 (即使开启了 WebP 转换)");
+console.log(simulateConvertLogic("image/gif", { url: "test.gif", format: "GIF" } as any, settings));
+
+console.log("\n场景 2: 伪装 URL 的 GIF (Sniffer 识别错误)");
+console.log(simulateConvertLogic("image/gif", { url: "test.jpg", format: "JPG" } as any, settings));
+
+console.log("\n场景 3: 跳过 GIF");
+console.log(simulateConvertLogic("image/gif", { url: "test.gif", format: "GIF" } as any, { ...settings, gifStrategy: "skip" } as any));
+
+console.log("\n场景 4: GIF 提取首帧");
+console.log(simulateConvertLogic("image/gif", { url: "test.gif", format: "GIF" } as any, { ...settings, gifStrategy: "firstFrame" } as any));

src/core/processor.ts

@@ -79,6 +79,10 @@ export class ImageProcessor {
             blob = converted.blob;
             extension = converted.extension;
           } catch (convErr) {
+            if (convErr instanceof Error && convErr.message === "SKIP_GIF") {
+              console.log(`[Processor] Skipping GIF after fetch: ${img.url}`);
+              continue;
+            }
             console.warn(
               `[Processor] Format conversion failed, using original:`,
               convErr,
@@ -189,6 +193,10 @@ export class ImageProcessor {
             blob = converted.blob;
             extension = converted.extension;
           } catch (convErr) {
+            if (convErr instanceof Error && convErr.message === "SKIP_GIF") {
+              console.log(`[Processor] ZIP: Skipping GIF after fetch: ${img.url}`);
+              continue;
+            }
             console.warn(`[Processor] ZIP conversion failed:`, convErr);
           }
 

src/core/utils/image-converter.ts

@@ -13,9 +13,11 @@ export async function convertImage(
   const quality = (settings.downloadLogic?.quality || 85) / 100;
 
   const originalFormat = img.format.toLowerCase();
+  const actualMimeType = blob.type.toLowerCase();
 
   // 1. Check if conversion is needed
-  const isGif = originalFormat === "gif";
+  // Use both metadata and actual blob type for robustness
+  const isGif = originalFormat === "gif" || actualMimeType === "image/gif";
 
   let shouldConvert = false;
 
@@ -25,24 +27,32 @@ export async function convertImage(
     extension = originalFormat !== "unknown" ? originalFormat : "png";
   } else {
     const urlExt = img.url.split(".").pop()?.split(/[?#]/)[0]?.toLowerCase();
-    extension =
-      urlExt && urlExt.length <= 5
-        ? urlExt
-        : originalFormat !== "unknown"
-          ? originalFormat
-          : "png";
+    // Prioritize original format if it's known and consistent with blob
+    if (originalFormat !== "unknown" && originalFormat.length <= 5) {
+      extension = originalFormat;
+    } else {
+      extension = urlExt && urlExt.length <= 5 ? urlExt : "png";
+    }
   }
+
+  // Final extension cleanup
   if (extension === "jpeg") extension = "jpg";
 
+  // GIF Special Handling: This should take PRECEDENCE over targetFormat
   if (isGif) {
-    if (gifStrategy === "firstFrame") {
+    if (gifStrategy === "keep") {
+      // Force .gif extension for kept GIFs
+      return { blob, extension: "gif" };
+    } else if (gifStrategy === "firstFrame") {
       shouldConvert = true;
-    } else if (gifStrategy === "keep") {
-      return { blob, extension };
+    } else if (gifStrategy === "skip") {
+      // If we somehow reached here with skip strategy (e.g. processor sniffer failure)
+      // we throw to allow processor to catch and skip
+      throw new Error("SKIP_GIF");
     }
-    // "skip" is handled in processor
   }
 
+  // Global format conversion (only if not already handled by gifStrategy or if it's a non-GIF)
   if (targetFormat !== "original") {
     // If target format is different from original, or if it's a GIF being flattened
     if (targetFormat !== originalFormat || isGif) {